Tomcat sets fields to null when unloading the web application.

h2/src/docsrc/html/changelog.html

@@ -24,11 +24,11 @@ Change Log
 </li><li>Connection.isValid is a bit faster.
 </li><li>H2 Console: The autocomplete feature has been improved a bit. It can now better
     parse conditions.
-</li><li>When restarting a web application in Tomcat, an exception is thrown sometimes.
-    In most cases this is a NullPointerException.
+</li><li>When restarting a web application in Tomcat, an exception was thrown sometimes.
+    In most cases this was a NullPointerException. A workaround in H2 has been implemented.
     The root cause of the problem is now documented in the FAQ:
     Tomcat sets all static fields (final or non-final) to null when unloading a web application.
-    A workaround is to set the system property
+    A workaround is to put the h2.jar in the lib directory, or set the system property
     org.apache.catalina.loader.WebappClassLoader.ENABLE_CLEAR_REFERENCES
     to false.
 </li></ul>

h2/src/docsrc/html/faq.html

@@ -46,17 +46,20 @@ Frequently Asked Questions
 Usually, bugs get fixes as they are found. There is a release every few weeks.
 Here is the list of known and confirmed issues:
 </p>
-<ul>
-<li>Some problems have been found with right outer join. Internally, it is converted to left outer join, which
-    does not always produce the same results as other databases when used in combination with other joins.
+<ul><li>Tomcat and Glassfish 3 sets all static fields (final or non-final) to null when 
+    unloading a web application. This can cause a NullPointerException in H2 versions 
+    1.1.107 and older, and may still not work in newer versions. Please report it if you 
+    run into this issue. In Tomcat >= 6.0 this behavior can be disabled by setting the 
+    system property org.apache.catalina.loader.WebappClassLoader.ENABLE_CLEAR_REFERENCES
+    to false, however Tomcat may then run out of memory. A known workaround is to 
+    put the h2.jar file in the <code>lib</code> directory.
+</li><li>Some problems have been found with right outer join. Internally, it is converted 
+    to left outer join, which does not always produce the same results as other databases 
+    when used in combination with other joins.
 </li><li>When using Install4j before 4.1.4 on Linux and enabling 'pack200',
     the h2*.jar becomes corrupted by the install process, causing application failure.
     A workaround is to add an empty file h2*.jar.nopack next to the h2*.jar file.
     This problem is solved in Install4j 4.1.4.
-</li><li>Tomcat sets all static fields (final or non-final) to null when unloading a web application.
-    This can cause a NullPointerException in H2. In Tomcat >= 6.0 this behavior can be disabled
-    by setting the system property org.apache.catalina.loader.WebappClassLoader.ENABLE_CLEAR_REFERENCES
-    to false.
 </li></ul>
 
 <br /><a name="open_source"></a>

h2/src/main/org/h2/command/Parser.java

@@ -659,7 +659,7 @@ public class Parser {
                 read("=");
                 Expression expression;
                 if (readIf("DEFAULT")) {
-                    expression = ValueExpression.DEFAULT;
+                    expression = ValueExpression.getDefault();
                 } else {
                     expression = readExpression();
                 }
@@ -2344,7 +2344,7 @@ public class Parser {
             break;
         case NULL:
             read();
-            r = ValueExpression.NULL;
+            r = ValueExpression.getNull();
             break;
         case VALUE:
             r = ValueExpression.get(currentValue);
@@ -2376,7 +2376,7 @@ public class Parser {
     private Expression readWhen(Expression left) throws SQLException {
         if (readIf("END")) {
             readIf("CASE");
-            return ValueExpression.NULL;
+            return ValueExpression.getNull();
         }
         if (readIf("ELSE")) {
             Expression elsePart = readExpression();

h2/src/main/org/h2/command/dml/ScriptBase.java

@@ -87,7 +87,7 @@ public abstract class ScriptBase extends Prepared implements DataHandler {
             if (fileName == null || fileName.trim().length() == 0) {
                 fileName = "script.sql";
             }
-            fileName = SysProperties.scriptDirectory + fileName;
+            fileName = SysProperties.getScriptDirectory() + fileName;
         }
         return fileName;
     }

h2/src/main/org/h2/command/dml/ScriptCommand.java

 /*
- * Copyright 2004-2009 H2 Group. Multiple-Licensed under the H2 License,
- * Version 1.0, and under the Eclipse Public License, Version 1.0
- * (http://h2database.com/html/license.html).
- * Initial Developer: H2 Group
+ * Copyright 2004-2009 H2 Group. Multiple-Licensed under the H2 License, Version
+ * 1.0, and under the Eclipse Public License, Version 1.0
+ * (http://h2database.com/html/license.html). Initial Developer: H2 Group
  */
 package org.h2.command.dml;
 
@@ -16,7 +15,6 @@ import java.sql.PreparedStatement;
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.util.Comparator;
-
 import org.h2.command.Parser;
 import org.h2.constant.SysProperties;
 import org.h2.constraint.Constraint;
@@ -61,14 +59,6 @@ import org.h2.value.ValueString;
  */
 public class ScriptCommand extends ScriptBase {
 
-    private static final Comparator TABLE_COMPARATOR = new Comparator() {
-        public int compare(Object o1, Object o2) {
-            Table t1 = (Table) o1;
-            Table t2 = (Table) o2;
-            return t1.getId() - t2.getId();
-        }
-    };
-
     private boolean passwords;
     private boolean data;
     private boolean settings;
@@ -196,7 +186,13 @@ public class ScriptCommand extends ScriptBase {
             ObjectArray tables = db.getAllSchemaObjects(DbObject.TABLE_OR_VIEW);
             // sort by id, so that views are after tables and views on views
             // after the base views
-            tables.sort(TABLE_COMPARATOR);
+            tables.sort(new Comparator() {
+                public int compare(Object o1, Object o2) {
+                    Table t1 = (Table) o1;
+                    Table t2 = (Table) o2;
+                    return t1.getId() - t2.getId();
+                }
+            });
             for (int i = 0; i < tables.size(); i++) {
                 Table table = (Table) tables.get(i);
                 table.lock(session, false, false);

h2/src/main/org/h2/command/dml/SetTypes.java

@@ -6,7 +6,7 @@
  */
 package org.h2.command.dml;
 
-import org.h2.util.ObjectArray;
+import java.util.ArrayList;
 
 /**
  * The list of setting for a SET statement.
@@ -193,56 +193,51 @@ public class SetTypes {
      */
     public static final int QUERY_TIMEOUT = 36;
 
-    private static ObjectArray types = new ObjectArray();
-
-    static {
-        setType(IGNORECASE, "IGNORECASE");
-        setType(MAX_LOG_SIZE, "MAX_LOG_SIZE");
-        setType(MODE, "MODE");
-        setType(READONLY, "READONLY");
-        setType(LOCK_TIMEOUT, "LOCK_TIMEOUT");
-        setType(DEFAULT_LOCK_TIMEOUT, "DEFAULT_LOCK_TIMEOUT");
-        setType(DEFAULT_TABLE_TYPE, "DEFAULT_TABLE_TYPE");
-        setType(CACHE_SIZE, "CACHE_SIZE");
-        setType(TRACE_LEVEL_SYSTEM_OUT, "TRACE_LEVEL_SYSTEM_OUT");
-        setType(TRACE_LEVEL_FILE, "TRACE_LEVEL_FILE");
-        setType(TRACE_MAX_FILE_SIZE, "TRACE_MAX_FILE_SIZE");
-        setType(COLLATION, "COLLATION");
-        setType(CLUSTER, "CLUSTER");
-        setType(WRITE_DELAY, "WRITE_DELAY");
-        setType(DATABASE_EVENT_LISTENER, "DATABASE_EVENT_LISTENER");
-        setType(MAX_MEMORY_ROWS, "MAX_MEMORY_ROWS");
-        setType(LOCK_MODE, "LOCK_MODE");
-        setType(DB_CLOSE_DELAY, "DB_CLOSE_DELAY");
-        setType(LOG, "LOG");
-        setType(THROTTLE, "THROTTLE");
-        setType(MAX_MEMORY_UNDO, "MAX_MEMORY_UNDO");
-        setType(MAX_LENGTH_INPLACE_LOB, "MAX_LENGTH_INPLACE_LOB");
-        setType(COMPRESS_LOB, "COMPRESS_LOB");
-        setType(ALLOW_LITERALS, "ALLOW_LITERALS");
-        setType(MULTI_THREADED, "MULTI_THREADED");
-        setType(SCHEMA, "SCHEMA");
-        setType(OPTIMIZE_REUSE_RESULTS, "OPTIMIZE_REUSE_RESULTS");
-        setType(SCHEMA_SEARCH_PATH, "SCHEMA_SEARCH_PATH");
-        setType(UNDO_LOG, "UNDO_LOG");
-        setType(REFERENTIAL_INTEGRITY, "REFERENTIAL_INTEGRITY");
-        setType(MVCC, "MVCC");
-        setType(MAX_OPERATION_MEMORY, "MAX_OPERATION_MEMORY");
-        setType(EXCLUSIVE, "EXCLUSIVE");
-        setType(CREATE_BUILD, "CREATE_BUILD");
-        setType(VARIABLE, "@");
-        setType(QUERY_TIMEOUT, "QUERY_TIMEOUT");
-    }
+    private static final ArrayList TYPES = new ArrayList();
 
     private SetTypes() {
         // utility class
     }
 
-    private static void setType(int type, String name) {
-        while (types.size() <= type) {
-            types.add(null);
-        }
-        types.set(type, name);
+    static {
+        ArrayList list = TYPES;
+        list.add(null);
+        list.add(IGNORECASE, "IGNORECASE");
+        list.add(MAX_LOG_SIZE, "MAX_LOG_SIZE");
+        list.add(MODE, "MODE");
+        list.add(READONLY, "READONLY");
+        list.add(LOCK_TIMEOUT, "LOCK_TIMEOUT");
+        list.add(DEFAULT_LOCK_TIMEOUT, "DEFAULT_LOCK_TIMEOUT");
+        list.add(DEFAULT_TABLE_TYPE, "DEFAULT_TABLE_TYPE");
+        list.add(CACHE_SIZE, "CACHE_SIZE");
+        list.add(TRACE_LEVEL_SYSTEM_OUT, "TRACE_LEVEL_SYSTEM_OUT");
+        list.add(TRACE_LEVEL_FILE, "TRACE_LEVEL_FILE");
+        list.add(TRACE_MAX_FILE_SIZE, "TRACE_MAX_FILE_SIZE");
+        list.add(COLLATION, "COLLATION");
+        list.add(CLUSTER, "CLUSTER");
+        list.add(WRITE_DELAY, "WRITE_DELAY");
+        list.add(DATABASE_EVENT_LISTENER, "DATABASE_EVENT_LISTENER");
+        list.add(MAX_MEMORY_ROWS, "MAX_MEMORY_ROWS");
+        list.add(LOCK_MODE, "LOCK_MODE");
+        list.add(DB_CLOSE_DELAY, "DB_CLOSE_DELAY");
+        list.add(LOG, "LOG");
+        list.add(THROTTLE, "THROTTLE");
+        list.add(MAX_MEMORY_UNDO, "MAX_MEMORY_UNDO");
+        list.add(MAX_LENGTH_INPLACE_LOB, "MAX_LENGTH_INPLACE_LOB");
+        list.add(COMPRESS_LOB, "COMPRESS_LOB");
+        list.add(ALLOW_LITERALS, "ALLOW_LITERALS");
+        list.add(MULTI_THREADED, "MULTI_THREADED");
+        list.add(SCHEMA, "SCHEMA");
+        list.add(OPTIMIZE_REUSE_RESULTS, "OPTIMIZE_REUSE_RESULTS");
+        list.add(SCHEMA_SEARCH_PATH, "SCHEMA_SEARCH_PATH");
+        list.add(UNDO_LOG, "UNDO_LOG");
+        list.add(REFERENTIAL_INTEGRITY, "REFERENTIAL_INTEGRITY");
+        list.add(MVCC, "MVCC");
+        list.add(MAX_OPERATION_MEMORY, "MAX_OPERATION_MEMORY");
+        list.add(EXCLUSIVE, "EXCLUSIVE");
+        list.add(CREATE_BUILD, "CREATE_BUILD");
+        list.add(VARIABLE, "@");
+        list.add(QUERY_TIMEOUT, "QUERY_TIMEOUT");
     }
 
     /**
@@ -252,16 +247,16 @@ public class SetTypes {
      * @return the number
      */
     public static int getType(String name) {
-        for (int i = 0; i < types.size(); i++) {
-            if (name.equals(types.get(i))) {
+        for (int i = 0; i < getTypes().size(); i++) {
+            if (name.equals(getTypes().get(i))) {
                 return i;
             }
         }
         return -1;
     }
 
-    public static ObjectArray getSettings() {
-        return types;
+    public static ArrayList getTypes() {
+        return TYPES;
     }
 
     /**
@@ -271,7 +266,7 @@ public class SetTypes {
      * @return the name
      */
     public static String getTypeName(int type) {
-        return (String) types.get(type);
+        return (String) getTypes().get(type);
     }
 
 }

h2/src/main/org/h2/command/dml/Update.java

@@ -94,7 +94,7 @@ public class Update extends Prepared {
                         Value newValue;
                         if (newExpr == null) {
                             newValue = oldRow.getValue(i);
-                        } else if (newExpr == ValueExpression.DEFAULT) {
+                        } else if (newExpr == ValueExpression.getDefault()) {
                             Column column = table.getColumn(i);
                             Expression defaultExpr = column.getDefaultExpression();
                             Value v;

h2/src/main/org/h2/compress/CompressLZF.java

@@ -45,7 +45,7 @@ public class CompressLZF implements Compressor {
     private static final int MAX_OFF = 1 << 13;
     private static final int MAX_REF = (1 << 8) + (1 << 3);
 
-    private int[] hashTab;
+    private int[] cachedHashTable;
 
     public void setOptions(String options) {
         // nothing to do
@@ -70,11 +70,12 @@ public class CompressLZF implements Compressor {
 
     public int compress(byte[] in, int inLen, byte[] out, int outPos) {
         int inPos = 0;
-        if (hashTab == null) {
-            hashTab = new int[HASH_SIZE];
+        if (cachedHashTable == null) {
+            cachedHashTable = new int[HASH_SIZE];
         } else {
-            System.arraycopy(EMPTY, 0, hashTab, 0, HASH_SIZE);
+            System.arraycopy(EMPTY, 0, cachedHashTable, 0, HASH_SIZE);
         }
+        int[] hashTab = cachedHashTable;
         int literals = 0;
         int hash = first(in, inPos);
         while (true) {

h2/src/main/org/h2/constant/SysProperties.java

@@ -492,14 +492,6 @@ public class SysProperties {
      */
     public static boolean runFinalize = getBooleanSetting("h2.runFinalize", true);
 
-    /**
-     * System property <code>h2.scriptDirectory</code> (default: empty
-     * string).<br />
-     * Relative or absolute directory where the script files are stored to or
-     * read from.
-     */
-    public static String scriptDirectory = getStringSetting("h2.scriptDirectory", "");
-
     /**
      * System property <code>h2.serverCachedObjects</code> (default: 64).<br />
      * TCP Server: number of cached objects per session.
@@ -566,7 +558,7 @@ public class SysProperties {
      */
     public static final int COLLATOR_CACHE_SIZE = getCollatorCacheSize();
 
-    private static String baseDir = getStringSetting("h2.baseDir", null);
+    private static final String H2_BASE_DIR = "h2.baseDir";
 
     private SysProperties() {
         // utility class
@@ -623,14 +615,32 @@ public class SysProperties {
         if (!dir.endsWith("/")) {
             dir += "/";
         }
-        baseDir = dir;
+        System.setProperty(H2_BASE_DIR, dir);
     }
 
     /**
      * INTERNAL
      */
     public static String getBaseDir() {
-        return baseDir;
+        return getStringSetting(H2_BASE_DIR, null);
+    }
+
+    /**
+     * INTERNAL
+     * System property <code>h2.scriptDirectory</code> (default: empty
+     * string).<br />
+     * Relative or absolute directory where the script files are stored to or
+     * read from.
+     */
+    public static String getScriptDirectory() {
+        return getStringSetting("h2.scriptDirectory", "");
+    }
+
+    /**
+     * INTERNAL
+     */
+    public static void setScriptDirectory(String dir) {
+        System.setProperty("h2.scriptDirectory", dir);
     }
 
     /**

h2/src/main/org/h2/engine/ConnectionInfo.java

@@ -7,10 +7,10 @@
 package org.h2.engine;
 
 import java.sql.SQLException;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashSet;
 import java.util.Properties;
-
 import org.h2.api.DatabaseEventListener;
 import org.h2.command.dml.SetTypes;
 import org.h2.constant.ErrorCode;
@@ -20,7 +20,6 @@ import org.h2.security.SHA256;
 import org.h2.util.ByteUtils;
 import org.h2.util.FileUtils;
 import org.h2.util.MathUtils;
-import org.h2.util.ObjectArray;
 import org.h2.util.StringUtils;
 
 /**
@@ -44,25 +43,6 @@ public class ConnectionInfo implements Cloneable {
     private boolean persistent;
     private boolean unnamed;
 
-    static {
-        ObjectArray list = SetTypes.getSettings();
-        for (int i = 0; i < list.size(); i++) {
-            KNOWN_SETTINGS.add(list.get(i));
-        }
-        // TODO document these settings
-        String[] connectionTime = new String[] { "ACCESS_MODE_LOG", "ACCESS_MODE_DATA", "AUTOCOMMIT", "CIPHER",
-                "CREATE", "CACHE_TYPE", "DB_CLOSE_ON_EXIT", "FILE_LOCK", "IGNORE_UNKNOWN_SETTINGS", "IFEXISTS",
-                "PASSWORD", "RECOVER", "USER", "DATABASE_EVENT_LISTENER_OBJECT", "AUTO_SERVER",
-                "AUTO_RECONNECT", "OPEN_NEW" };
-        for (int i = 0; i < connectionTime.length; i++) {
-            String key = connectionTime[i];
-            if (SysProperties.CHECK && KNOWN_SETTINGS.contains(key)) {
-                Message.throwInternalError(key);
-            }
-            KNOWN_SETTINGS.add(key);
-        }
-    }
-
     /**
      * Create a connection info object.
      *
@@ -93,6 +73,30 @@ public class ConnectionInfo implements Cloneable {
         parseName();
     }
 
+    static {
+        ArrayList list = SetTypes.getTypes();
+        HashSet set = KNOWN_SETTINGS;
+        for (int i = 0; i < list.size(); i++) {
+            set.add(list.get(i));
+        }
+        // TODO document these settings
+        String[] connectionTime = new String[] { "ACCESS_MODE_LOG", "ACCESS_MODE_DATA", "AUTOCOMMIT", "CIPHER",
+                "CREATE", "CACHE_TYPE", "DB_CLOSE_ON_EXIT", "FILE_LOCK", "IGNORE_UNKNOWN_SETTINGS", "IFEXISTS",
+                "PASSWORD", "RECOVER", "USER", "DATABASE_EVENT_LISTENER_OBJECT", "AUTO_SERVER",
+                "AUTO_RECONNECT", "OPEN_NEW" };
+        for (int i = 0; i < connectionTime.length; i++) {
+            String key = connectionTime[i];
+            if (SysProperties.CHECK && set.contains(key)) {
+                Message.throwInternalError(key);
+            }
+            set.add(key);
+        }
+    }
+
+    private static boolean isKnownSetting(String s) {
+        return KNOWN_SETTINGS.contains(s);
+    }
+
     public Object clone() throws CloneNotSupportedException {
         ConnectionInfo clone = (ConnectionInfo) super.clone();
         clone.prop = (Properties) prop.clone();
@@ -174,7 +178,7 @@ public class ConnectionInfo implements Cloneable {
             if (prop.containsKey(key)) {
                 throw Message.getSQLException(ErrorCode.DUPLICATE_PROPERTY_1, key);
             }
-            if (KNOWN_SETTINGS.contains(key)) {
+            if (isKnownSetting(key)) {
                 prop.put(key, info.get(list[i]));
             }
         }
@@ -195,7 +199,7 @@ public class ConnectionInfo implements Cloneable {
                 String value = setting.substring(equal + 1);
                 String key = setting.substring(0, equal);
                 key = StringUtils.toUpperEnglish(key);
-                if (!KNOWN_SETTINGS.contains(key)) {
+                if (!isKnownSetting(key)) {
                     throw Message.getSQLException(ErrorCode.UNSUPPORTED_SETTING_1, key);
                 }
                 String old = prop.getProperty(key);
@@ -293,7 +297,7 @@ public class ConnectionInfo implements Cloneable {
      * @return the value
      */
     String removeProperty(String key, String defaultValue) {
-        if (SysProperties.CHECK && !KNOWN_SETTINGS.contains(key)) {
+        if (SysProperties.CHECK && !isKnownSetting(key)) {
             Message.throwInternalError(key);
         }
         Object x = prop.remove(key);
@@ -378,7 +382,7 @@ public class ConnectionInfo implements Cloneable {
      * @return the value as a String
      */
     public String getProperty(String key, String defaultValue) {
-        if (SysProperties.CHECK && !KNOWN_SETTINGS.contains(key)) {
+        if (SysProperties.CHECK && !isKnownSetting(key)) {
             Message.throwInternalError(key);
         }
         String s = getProperty(key);

h2/src/main/org/h2/engine/Database.java

@@ -60,7 +60,6 @@ import org.h2.util.CacheLRU;
 import org.h2.util.ClassUtils;
 import org.h2.util.FileUtils;
 import org.h2.util.IntHashMap;
-import org.h2.util.MemoryUtils;
 import org.h2.util.NetUtils;
 import org.h2.util.ObjectArray;
 import org.h2.util.SmallLRUCache;
@@ -1007,14 +1006,6 @@ public class Database implements DataHandler {
         if (closing) {
             return;
         }
-        if (MemoryUtils.isShutdown()) {
-            try {
-                traceSystem.getTrace(Trace.DATABASE).error("already shut down");
-            } catch (Exception e) {
-                // ignore
-            }
-            return;
-        }
         closing = true;
         stopServer();
         if (userSessions.size() > 0) {

h2/src/main/org/h2/engine/Engine.java

@@ -27,9 +27,8 @@ import org.h2.util.StringUtils;
 public class Engine {
 
     private static final Engine INSTANCE = new Engine();
+    private static final HashMap DATABASES = new HashMap();
     private static volatile long wrongPasswordDelay = SysProperties.DELAY_WRONG_PASSWORD_MIN;
-    private static Object wrongPasswordSync = new Object();
-    private final HashMap databases = new HashMap();
 
     private Engine() {
         // don't allow others to instantiate
@@ -46,7 +45,7 @@ public class Engine {
         if (openNew || ci.isUnnamedInMemory()) {
             database = null;
         } else {
-            database = (Database) databases.get(name);
+            database = (Database) DATABASES.get(name);
         }
         User user = null;
         boolean opened = false;
@@ -65,7 +64,7 @@ public class Engine {
                 database.setMasterUser(user);
             }
             if (!ci.isUnnamedInMemory()) {
-                databases.put(name, database);
+                DATABASES.put(name, database);
             }
             database.opened();
         }
@@ -182,7 +181,7 @@ public class Engine {
      * @param name the database name
      */
     public void close(String name) {
-        databases.remove(name);
+        DATABASES.remove(name);
     }
 
     /**
@@ -208,10 +207,10 @@ public class Engine {
             if (delay > min && delay > 0) {
                 // the first correct password must be blocked,
                 // otherwise parallel attacks are possible
-                synchronized (wrongPasswordSync) {
+                synchronized (INSTANCE) {
                     // delay up to the last delay
                     // an attacker can't know how long it will be
-                    delay = RandomUtils.nextInt((int) delay);
+                    delay = RandomUtils.nextSecureInt((int) delay);
                     try {
                         Thread.sleep(delay);
                     } catch (InterruptedException e) {
@@ -223,7 +222,7 @@ public class Engine {
         } else {
             // this method is not synchronized on the Engine, so that
             // regular successful attempts are not blocked
-            synchronized (wrongPasswordSync) {
+            synchronized (INSTANCE) {
                 long delay = wrongPasswordDelay;
                 int max = SysProperties.DELAY_WRONG_PASSWORD_MAX;
                 if (max <= 0) {

h2/src/main/org/h2/engine/MetaRecord.java

@@ -24,19 +24,6 @@ import org.h2.value.ValueString;
  */
 public class MetaRecord {
 
-    private static final Comparator META_RECORD_COMPARATOR = new Comparator() {
-        public int compare(Object o1, Object o2) {
-            MetaRecord m1 = (MetaRecord) o1;
-            MetaRecord m2 = (MetaRecord) o2;
-            int c1 = DbObjectBase.getCreateOrder(m1.getObjectType());
-            int c2 = DbObjectBase.getCreateOrder(m2.getObjectType());
-            if (c1 != c2) {
-                return c1 - c2;
-            }
-            return m1.getId() - m2.getId();
-        }
-    };
-
     private int id;
     private int objectType;
     private int headPos;
@@ -62,7 +49,18 @@ public class MetaRecord {
      * @param records the list of meta records
      */
     public static void sort(ObjectArray records) {
-        records.sort(META_RECORD_COMPARATOR);
+        records.sort(new Comparator() {
+            public int compare(Object o1, Object o2) {
+                MetaRecord m1 = (MetaRecord) o1;
+                MetaRecord m2 = (MetaRecord) o2;
+                int c1 = DbObjectBase.getCreateOrder(m1.getObjectType());
+                int c2 = DbObjectBase.getCreateOrder(m2.getObjectType());
+                if (c1 != c2) {
+                    return c1 - c2;
+                }
+                return m1.getId() - m2.getId();
+            }
+        });
     }
 
     void setRecord(SearchRow r) {

h2/src/main/org/h2/expression/CompareLike.java

@@ -76,7 +76,7 @@ public class CompareLike extends Condition {
             Value l = left.getValue(session);
             if (l == ValueNull.INSTANCE) {
                 // NULL LIKE something > NULL
-                return ValueExpression.NULL;
+                return ValueExpression.getNull();
             }
         }
         if (escape != null) {
@@ -89,11 +89,11 @@ public class CompareLike extends Condition {
             Value r = right.getValue(session);
             if (r == ValueNull.INSTANCE) {
                 // something LIKE NULL > NULL
-                return ValueExpression.NULL;
+                return ValueExpression.getNull();
             }
             Value e = escape == null ? null : escape.getValue(session);
             if (e == ValueNull.INSTANCE) {
-                return ValueExpression.NULL;
+                return ValueExpression.getNull();
             }
             String p = r.getString();
             initPattern(p, getEscapeChar(e));

h2/src/main/org/h2/expression/Comparison.java

@@ -119,7 +119,7 @@ public class Comparison extends Condition {
 
     private Expression getCast(Expression expr, int dataType, long precision, int scale, int displaySize, Session session)
             throws SQLException {
-        if (expr == ValueExpression.NULL) {
+        if (expr == ValueExpression.getNull()) {
             return expr;
         }
         Function function = Function.getFunction(session.getDatabase(), "CAST");
@@ -186,10 +186,10 @@ public class Comparison extends Condition {
             if (SysProperties.CHECK && (left == null || right == null)) {
                 Message.throwInternalError();
             }
-            if (left == ValueExpression.NULL || right == ValueExpression.NULL) {
+            if (left == ValueExpression.getNull() || right == ValueExpression.getNull()) {
                 // TODO NULL handling: maybe issue a warning when comparing with
                 // a NULL constants
-                return ValueExpression.NULL;
+                return ValueExpression.getNull();
             }
             if (left.isConstant() && right.isConstant()) {
                 return ValueExpression.get(getValue(session));

h2/src/main/org/h2/expression/ConditionIn.java

@@ -85,7 +85,7 @@ public class ConditionIn extends Condition {
         }
         left = left.optimize(session);
         boolean constant = left.isConstant();
-        if (constant && left == ValueExpression.NULL) {
+        if (constant && left == ValueExpression.getNull()) {
             return left;
         }
         boolean allValuesConstant = true;

h2/src/main/org/h2/expression/ConditionNot.java

@@ -55,7 +55,7 @@ public class ConditionNot extends Condition {
         if (expr.isConstant()) {
             Value v = expr.getValue(session);
             if (v == ValueNull.INSTANCE) {
-                return ValueExpression.NULL;
+                return ValueExpression.getNull();
             }
             return ValueExpression.get(v.convertTo(Value.BOOLEAN).negate());
         }

h2/src/main/org/h2/expression/Function.java

@@ -1621,7 +1621,7 @@ public class Function extends Expression implements FunctionCall {
             displaySize = 0;
             for (int i = 0; i < args.length; i++) {
                 Expression e = args[i];
-                if (e != ValueExpression.NULL && e.getType() != Value.UNKNOWN) {
+                if (e != ValueExpression.getNull() && e.getType() != Value.UNKNOWN) {
                     dataType = Value.getHigherOrder(dataType, e.getType());
                     scale = Math.max(scale, e.getScale());
                     precision = Math.max(precision, e.getPrecision());

h2/src/main/org/h2/expression/ValueExpression.java

@@ -22,21 +22,39 @@ public class ValueExpression extends Expression {
     /**
      * The expression represents ValueNull.INSTANCE.
      */
-    public static final ValueExpression NULL = new ValueExpression(ValueNull.INSTANCE);
+    private static final Object NULL = new ValueExpression(ValueNull.INSTANCE);
 
     /**
      * This special expression represents the default value. It is used for
      * UPDATE statements of the form SET COLUMN = DEFAULT. The value is
      * ValueNull.INSTANCE, but should never be accessed.
      */
-    public static final ValueExpression DEFAULT = new ValueExpression(ValueNull.INSTANCE);
+    private static final Object DEFAULT = new ValueExpression(ValueNull.INSTANCE);
 
-    private Value value;
+    private final Value value;
 
     private ValueExpression(Value value) {
         this.value = value;
     }
 
+    /**
+     * Get the NULL expression.
+     *
+     * @return the NULL expression
+     */
+    public static ValueExpression getNull() {
+        return (ValueExpression) NULL;
+    }
+
+    /**
+     * Get the DEFAULT expression.
+     *
+     * @return the DEFAULT expression
+     */
+    public static ValueExpression getDefault() {
+        return (ValueExpression) DEFAULT;
+    }
+
     /**
      * Create a new expression with the given value.
      *
@@ -45,7 +63,7 @@ public class ValueExpression extends Expression {
      */
     public static ValueExpression get(Value value) {
         if (value == ValueNull.INSTANCE) {
-            return ValueExpression.NULL;
+            return getNull();
         }
         return new ValueExpression(value);
     }

h2/src/main/org/h2/jdbcx/JdbcDataSourceFactory.java

@@ -30,20 +30,18 @@ implements ObjectFactory
 //## Java 1.4 end ##
 {
 
-    private static TraceSystem traceSystem;
+    private static TraceSystem cachedTraceSystem;
     private Trace trace;
 
     static {
         org.h2.Driver.load();
-        traceSystem = new TraceSystem(SysProperties.CLIENT_TRACE_DIRECTORY + "h2datasource" + Constants.SUFFIX_TRACE_FILE, false);
-        traceSystem.setLevelFile(SysProperties.DATASOURCE_TRACE_LEVEL);
     }
 
     /**
      * The public constructor to create new factory objects.
      */
     public JdbcDataSourceFactory() {
-        trace = traceSystem.getTrace("JDBCX");
+        trace = getTraceSystem().getTrace("JDBCX");
     }
 
     /**
@@ -77,8 +75,12 @@ implements ObjectFactory
     }
 //## Java 1.4 end ##
 
-    TraceSystem getTraceSystem() {
-        return traceSystem;
+    private TraceSystem getTraceSystem() {
+        if (cachedTraceSystem == null) {
+            cachedTraceSystem = new TraceSystem(SysProperties.CLIENT_TRACE_DIRECTORY + "h2datasource" + Constants.SUFFIX_TRACE_FILE, false);
+            cachedTraceSystem.setLevelFile(SysProperties.DATASOURCE_TRACE_LEVEL);
+        }
+        return cachedTraceSystem;
     }
 
     Trace getTrace() {

h2/src/main/org/h2/log/LogSystem.java

@@ -37,12 +37,6 @@ public class LogSystem {
      */
     public static final int LOG_WRITTEN = -1;
 
-    private static final Comparator LOG_FILE_COMPARATOR = new Comparator() {
-        public int compare(Object a, Object b) {
-            return ((LogFile) a).getId() - ((LogFile) b).getId();
-        }
-    };
-
     private Database database;
     private ObjectArray activeLogs;
     private LogFile currentLog;
@@ -319,7 +313,11 @@ public class LogSystem {
                 }
             }
         }
-        activeLogs.sort(LOG_FILE_COMPARATOR);
+        activeLogs.sort(new Comparator() {
+            public int compare(Object a, Object b) {
+                return ((LogFile) a).getId() - ((LogFile) b).getId();
+            }
+        });
         if (activeLogs.size() == 0) {
             LogFile l = new LogFile(this, 0, fileNamePrefix);
             activeLogs.add(l);

h2/src/main/org/h2/message/Message.java

@@ -78,7 +78,11 @@ public class Message {
     }
 
     private static String translate(String key, String[] param) {
-        String message = MESSAGES.getProperty(key);
+        String message = null;
+        if (MESSAGES != null) {
+            // Tomcat sets final static fields to null sometimes
+            message = MESSAGES.getProperty(key);
+        }
         if (message == null) {
             message = "(Message " + key + " not found)";
         }

h2/src/main/org/h2/store/DiskFile.java

@@ -80,18 +80,6 @@ public class DiskFile implements CacheWriter {
     private static final int OFFSET = FileStore.HEADER_LENGTH;
     private static final int FREE_PAGE = -1;
 
-    private static final Comparator REDO_LOG_COMPARATOR = new Comparator() {
-        public int compare(Object o1, Object o2) {
-            RedoLogRecord e1 = (RedoLogRecord) o1;
-            RedoLogRecord e2 = (RedoLogRecord) o2;
-            int comp = e1.recordId - e2.recordId;
-            if (comp == 0) {
-                comp = e1.sequenceId - e2.sequenceId;
-            }
-            return comp;
-        }
-    };
-
     private Database database;
     private String fileName;
     private FileStore file;
@@ -1203,7 +1191,17 @@ public class DiskFile implements CacheWriter {
             if (redoBuffer.size() == 0) {
                 return;
             }
-            redoBuffer.sort(REDO_LOG_COMPARATOR);
+            redoBuffer.sort(new Comparator() {
+                public int compare(Object o1, Object o2) {
+                    RedoLogRecord e1 = (RedoLogRecord) o1;
+                    RedoLogRecord e2 = (RedoLogRecord) o2;
+                    int comp = e1.recordId - e2.recordId;
+                    if (comp == 0) {
+                        comp = e1.sequenceId - e2.sequenceId;
+                    }
+                    return comp;
+                }
+            });
             // first write all deleted entries
             // because delete entries are always 1 block,
             // while not-deleted entries can be many blocks

h2/src/main/org/h2/store/fs/FileObjectMemory.java

@@ -25,7 +25,7 @@ public class FileObjectMemory implements FileObject {
     private static final int BLOCK_SIZE_MASK = BLOCK_SIZE - 1;
     private static final CompressLZF LZF = new CompressLZF();
     private static final byte[] BUFFER = new byte[BLOCK_SIZE * 2];
-    private static final byte[] COMPRESSED_BLOCK;
+    private static byte[] cachedCompressedEmptyBlock;
 
 //## Java 1.4 begin ##
     private static final Cache COMPRESS_LATER = new Cache(CACHE_SIZE);
@@ -137,11 +137,14 @@ public class FileObjectMemory implements FileObject {
         }
     }
 
-    static {
-        byte[] n = new byte[BLOCK_SIZE];
-        int len = LZF.compress(n, BLOCK_SIZE, BUFFER, 0);
-        COMPRESSED_BLOCK = new byte[len];
-        System.arraycopy(BUFFER, 0, COMPRESSED_BLOCK, 0, len);
+    static byte[] getCompressedEmptyBlock() {
+        if (cachedCompressedEmptyBlock == null) {
+            byte[] n = new byte[BLOCK_SIZE];
+            int len = LZF.compress(n, BLOCK_SIZE, BUFFER, 0);
+            cachedCompressedEmptyBlock = new byte[len];
+            System.arraycopy(BUFFER, 0, cachedCompressedEmptyBlock, 0, len);
+        }
+        return cachedCompressedEmptyBlock;
     }
 
     private void touch() {
@@ -186,7 +189,7 @@ public class FileObjectMemory implements FileObject {
             byte[][] n = new byte[blocks][];
             System.arraycopy(data, 0, n, 0, Math.min(data.length, n.length));
             for (int i = data.length; i < blocks; i++) {
-                n[i] = COMPRESSED_BLOCK;
+                n[i] = getCompressedEmptyBlock();
             }
             data = n;
         }

h2/src/main/org/h2/store/fs/FileSystemMemory.java

@@ -25,7 +25,7 @@ import org.h2.util.RandomUtils;
 public class FileSystemMemory extends FileSystem {
 
     private static final FileSystemMemory INSTANCE = new FileSystemMemory();
-    private final HashMap memoryFiles = new HashMap();
+    private static final HashMap MEMORY_FILES = new HashMap();
 
     private FileSystemMemory() {
         // don't allow construction
@@ -42,16 +42,16 @@ public class FileSystemMemory extends FileSystem {
     public void rename(String oldName, String newName) {
         oldName = normalize(oldName);
         newName = normalize(newName);
-        synchronized (memoryFiles) {
+        synchronized (MEMORY_FILES) {
             FileObjectMemory f = getMemoryFile(oldName);
             f.setName(newName);
-            memoryFiles.remove(oldName);
-            memoryFiles.put(newName, f);
+            MEMORY_FILES.remove(oldName);
+            MEMORY_FILES.put(newName, f);
         }
     }
 
     public boolean createNewFile(String fileName) {
-        synchronized (memoryFiles) {
+        synchronized (MEMORY_FILES) {
             if (exists(fileName)) {
                 return false;
             }
@@ -62,29 +62,29 @@ public class FileSystemMemory extends FileSystem {
 
     public boolean exists(String fileName) {
         fileName = normalize(fileName);
-        synchronized (memoryFiles) {
-            return memoryFiles.get(fileName) != null;
+        synchronized (MEMORY_FILES) {
+            return MEMORY_FILES.get(fileName) != null;
         }
     }
 
     public void delete(String fileName) {
         fileName = normalize(fileName);
-        synchronized (memoryFiles) {
-            memoryFiles.remove(fileName);
+        synchronized (MEMORY_FILES) {
+            MEMORY_FILES.remove(fileName);
         }
     }
 
     public boolean tryDelete(String fileName) {
         fileName = normalize(fileName);
-        synchronized (memoryFiles) {
-            memoryFiles.remove(fileName);
+        synchronized (MEMORY_FILES) {
+            MEMORY_FILES.remove(fileName);
         }
         return true;
     }
 
     public String createTempFile(String name, String suffix, boolean deleteOnExit, boolean inTempDir) {
         name += ".";
-        synchronized (memoryFiles) {
+        synchronized (MEMORY_FILES) {
             for (int i = 0;; i++) {
                 String n = name + (RandomUtils.getSecureLong() >>> 1) + suffix;
                 if (!exists(n)) {
@@ -97,8 +97,8 @@ public class FileSystemMemory extends FileSystem {
 
     public String[] listFiles(String path) {
         ObjectArray list = new ObjectArray();
-        synchronized (memoryFiles) {
-            for (Iterator it = memoryFiles.keySet().iterator(); it.hasNext();) {
+        synchronized (MEMORY_FILES) {
+            for (Iterator it = MEMORY_FILES.keySet().iterator(); it.hasNext();) {
                 String name = (String) it.next();
                 if (name.startsWith(path)) {
                     list.add(name);
@@ -112,8 +112,8 @@ public class FileSystemMemory extends FileSystem {
 
     public void deleteRecursive(String fileName) throws SQLException {
         fileName = normalize(fileName);
-        synchronized (memoryFiles) {
-            Iterator it = memoryFiles.keySet().iterator();
+        synchronized (MEMORY_FILES) {
+            Iterator it = MEMORY_FILES.keySet().iterator();
             while (it.hasNext()) {
                 String name = (String) it.next();
                 if (name.startsWith(fileName)) {
@@ -217,12 +217,12 @@ public class FileSystemMemory extends FileSystem {
 
     private FileObjectMemory getMemoryFile(String fileName) {
         fileName = normalize(fileName);
-        synchronized (memoryFiles) {
-            FileObjectMemory m = (FileObjectMemory) memoryFiles.get(fileName);
+        synchronized (MEMORY_FILES) {
+            FileObjectMemory m = (FileObjectMemory) MEMORY_FILES.get(fileName);
             if (m == null) {
                 boolean compress = fileName.startsWith(FileSystem.PREFIX_MEMORY_LZF);
                 m = new FileObjectMemory(fileName, compress);
-                memoryFiles.put(fileName, m);
+                MEMORY_FILES.put(fileName, m);
             }
             return m;
         }

h2/src/main/org/h2/table/MetaTable.java

@@ -16,6 +16,7 @@ import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.sql.Timestamp;
 import java.text.Collator;
+import java.util.ArrayList;
 import java.util.Locale;
 
 import org.h2.command.Command;
@@ -865,7 +866,7 @@ public class MetaTable extends Table {
             add(rows, new String[]{"h2.recompileAlways", "" + SysProperties.RECOMPILE_ALWAYS});
             add(rows, new String[]{"h2.redoBufferSize", "" + SysProperties.REDO_BUFFER_SIZE});
             add(rows, new String[]{"h2.runFinalize", "" + SysProperties.runFinalize});
-            add(rows, new String[]{"h2.scriptDirectory", SysProperties.scriptDirectory});
+            add(rows, new String[]{"h2.scriptDirectory", SysProperties.getScriptDirectory()});
             add(rows, new String[]{"h2.serverCachedObjects", "" + SysProperties.SERVER_CACHED_OBJECTS});
             add(rows, new String[]{"h2.serverResultSetFetchSize", "" + SysProperties.SERVER_RESULT_SET_FETCH_SIZE});
             add(rows, new String[]{"h2.sortNullsHigh", "" + SysProperties.SORT_NULLS_HIGH});
@@ -887,7 +888,7 @@ public class MetaTable extends Table {
             break;
         }
         case TYPE_INFO: {
-            ObjectArray types = DataType.getTypes();
+            ArrayList types = DataType.getTypes();
             for (int i = 0; i < types.size(); i++) {
                 DataType t = (DataType) types.get(i);
                 if (t.hidden || t.sqlType == Value.NULL) {

h2/src/main/org/h2/tools/CompressTool.java

@@ -34,22 +34,22 @@ import org.h2.util.StringUtils;
  */
 public class CompressTool {
 
-    private static CompressTool instance = new CompressTool();
-    private static byte[] buffer;
-    private static final int MAX_BUFFER_SIZE = 64 * 1024 * 1024;
+    private static final CompressTool INSTANCE = new CompressTool();
+    private static final int MAX_BUFFER_SIZE = 64 * 1024;
+    private byte[] cachedBuffer;
 
     private CompressTool() {
         // don't allow construction
     }
 
-    private static byte[] getBuffer(int min) {
+    private byte[] getBuffer(int min) {
         if (min > MAX_BUFFER_SIZE) {
             return ByteUtils.newBytes(min);
         }
-        if (buffer == null || buffer.length < min) {
-            buffer = ByteUtils.newBytes(min);
+        if (cachedBuffer == null || cachedBuffer.length < min) {
+            cachedBuffer = ByteUtils.newBytes(min);
         }
-        return buffer;
+        return cachedBuffer;
     }
 
     /**
@@ -58,7 +58,7 @@ public class CompressTool {
      * @return the singleton
      */
     public static CompressTool getInstance() {
-        return instance;
+        return INSTANCE;
     }
 
     /**

h2/src/main/org/h2/tools/MultiDimension.java

@@ -23,7 +23,7 @@ import org.h2.util.StringUtils;
  */
 public class MultiDimension {
 
-    private static MultiDimension instance = new MultiDimension();
+    private static final MultiDimension INSTANCE = new MultiDimension();
 
     private MultiDimension() {
         // don't allow construction
@@ -35,7 +35,7 @@ public class MultiDimension {
      * @return the singleton
      */
     public static MultiDimension getInstance() {
-        return instance;
+        return INSTANCE;
     }
 
     /**

h2/src/main/org/h2/util/CacheObject.java

@@ -18,11 +18,9 @@ import org.h2.store.DiskFile;
 public abstract class CacheObject {
 
     /**
-     * Ensure the class is loaded when initialized, so that sorting is possible
-     * even when loading new classes is not allowed any more. This can occur
-     * when stopping a web application.
+     * Compare cache objects by position.
      */
-    private static final Comparator CACHE_COMPARATOR = new Comparator() {
+    private static class CacheComparator implements Comparator {
         public int compare(Object a, Object b) {
             int pa = ((CacheObject) a).getPos();
             int pb = ((CacheObject) b).getPos();
@@ -30,6 +28,15 @@ public abstract class CacheObject {
         }
     };
 
+    /**
+     * Ensure the class is loaded when initialized, so that sorting is possible
+     * even when loading new classes is not allowed any more. This can occur
+     * when stopping a web application.
+     */
+    static {
+        new CacheComparator();
+    }
+
     /**
      * The previous element in the LRU linked list. If the previous element is
      * the head, then this element is the most recently used object.
@@ -75,7 +82,7 @@ public abstract class CacheObject {
      * @param recordList the list of cache objects
      */
     public static void sort(ObjectArray recordList) {
-        recordList.sort(CACHE_COMPARATOR);
+        recordList.sort(new CacheComparator());
     }
 
     public void setBlockCount(int size) {

h2/src/main/org/h2/util/DateTimeUtils.java

@@ -30,7 +30,7 @@ public class DateTimeUtils {
     private static final int DEFAULT_DAY = 1;
     private static final int DEFAULT_HOUR = 0;
 
-    private static Calendar calendar = Calendar.getInstance();
+    private static Calendar cachedCalendar = Calendar.getInstance();
 
     private DateTimeUtils() {
         // utility class
@@ -40,7 +40,14 @@ public class DateTimeUtils {
      * Reset the calendar, for example after changing the default timezone.
      */
     public static void resetCalendar() {
-        calendar = Calendar.getInstance();
+        cachedCalendar = null;
+    }
+
+    private static Calendar getCalendar() {
+        if (cachedCalendar == null) {
+            cachedCalendar = Calendar.getInstance();
+        }
+        return cachedCalendar;
     }
 
     /**
@@ -67,7 +74,7 @@ public class DateTimeUtils {
      * @return the time value without the date component
      */
     public static Time cloneAndNormalizeTime(Time value) {
-        Calendar cal = calendar;
+        Calendar cal = getCalendar();
         long time;
         synchronized (cal) {
             cal.setTime(value);
@@ -86,7 +93,7 @@ public class DateTimeUtils {
      * @return the date value at midnight
      */
     public static Date cloneAndNormalizeDate(Date value) {
-        Calendar cal = calendar;
+        Calendar cal = getCalendar();
         long time;
         synchronized (cal) {
             cal.setTime(value);
@@ -147,7 +154,7 @@ public class DateTimeUtils {
             throw Message.getInvalidValueException("calendar", null);
         }
         source = (Calendar) source.clone();
-        Calendar universal = calendar;
+        Calendar universal = getCalendar();
         synchronized (universal) {
             source.setTime(x);
             convertTime(source, universal);
@@ -334,7 +341,7 @@ public class DateTimeUtils {
     private static long getTime(boolean lenient, TimeZone tz, int year, int month, int day, int hour, int minute, int second, boolean setMillis, int nano) {
         Calendar c;
         if (tz == null) {
-            c = calendar;
+            c = getCalendar();
         } else {
             c = Calendar.getInstance(tz);
         }
@@ -369,7 +376,7 @@ public class DateTimeUtils {
      * @return the value
      */
     public static int getDatePart(java.util.Date d, int field) {
-        Calendar c = calendar;
+        Calendar c = getCalendar();
         int value;
         synchronized (c) {
             c.setTime(d);

h2/src/main/org/h2/util/JdbcDriverUtils.java

@@ -75,8 +75,4 @@ public class JdbcDriverUtils {
         }
     }
 
-    static boolean isShutdown() {
-        return DRIVERS == null;
-    }
-
 }

h2/src/main/org/h2/util/MemoryUtils.java

@@ -80,16 +80,4 @@ public class MemoryUtils {
         reserveMemory = null;
     }
 
-    /**
-     * Check if Tomcat has set the static references to null,
-     * which can cause a NullPointerException. A workaround is to
-     * disable the system property org.apache.catalina.loader.
-     * WebappClassLoader.ENABLE_CLEAR_REFERENCES
-     *
-     * @return true if static references are set to null
-     */
-    public static boolean isShutdown() {
-        return StringCache.isShutdown() || JdbcDriverUtils.isShutdown() || Resources.isShutdown();
-    }
-
 }

h2/src/main/org/h2/util/RandomUtils.java

@@ -25,28 +25,29 @@ public class RandomUtils {
     /**
      * The secure random object.
      */
-    static SecureRandom secureRandom;
+    static SecureRandom cachedSecureRandom;
 
     /**
      * True if the secure random object is seeded.
      */
     static volatile boolean seeded;
-    private static Random random  = new Random();
+
+    private static final Random RANDOM  = new Random();
 
     private RandomUtils() {
         // utility class
     }
 
     private static synchronized SecureRandom getSecureRandom() {
-        if (secureRandom != null) {
-            return secureRandom;
+        if (cachedSecureRandom != null) {
+            return cachedSecureRandom;
         }
         // Workaround for SecureRandom problem as described in
         // http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6202721
         // Can not do that in a static initializer block, because
-        // threads are not started after the initializer block exits
+        // threads are not started until after the initializer block exits
         try {
-            secureRandom = SecureRandom.getInstance("SHA1PRNG");
+            cachedSecureRandom = SecureRandom.getInstance("SHA1PRNG");
             // On some systems, secureRandom.generateSeed() is very slow.
             // In this case it is initialized using our own seed implementation
             // and afterwards (in the thread) using the regular algorithm.
@@ -55,8 +56,8 @@ public class RandomUtils {
                     try {
                         SecureRandom sr = SecureRandom.getInstance("SHA1PRNG");
                         byte[] seed = sr.generateSeed(20);
-                        synchronized (secureRandom) {
-                            secureRandom.setSeed(seed);
+                        synchronized (cachedSecureRandom) {
+                            cachedSecureRandom.setSeed(seed);
                             seeded = true;
                         }
                     } catch (NoSuchAlgorithmException e) {
@@ -78,15 +79,15 @@ public class RandomUtils {
             if (!seeded) {
                 byte[] seed = generateAlternativeSeed();
                 // this never reduces randomness
-                synchronized (secureRandom) {
-                    secureRandom.setSeed(seed);
+                synchronized (cachedSecureRandom) {
+                    cachedSecureRandom.setSeed(seed);
                 }
             }
         } catch (NoSuchAlgorithmException e) {
             warn("SecureRandom", e);
-            secureRandom = new SecureRandom();
+            cachedSecureRandom = new SecureRandom();
         }
-        return secureRandom;
+        return cachedSecureRandom;
     }
 
     private static byte[] generateAlternativeSeed() {
@@ -183,15 +184,29 @@ public class RandomUtils {
         return buff;
     }
 
+    /**
+     * Get a pseudo random int value between 0 (including and the given value
+     * (excluding). The value is not cryptographically secure.
+     *
+     * @param lowerThan the value returned will be lower than this value
+     * @return the random long value
+     */
+    public static int nextInt(int lowerThan) {
+        return RANDOM.nextInt(lowerThan);
+    }
+
     /**
      * Get a cryptographically secure pseudo random int value between 0
      * (including and the given value (excluding).
      *
-     * @param lower the value returned will be lower than this value
+     * @param lowerThan the value returned will be lower than this value
      * @return the random long value
      */
-    public static int nextInt(int lower) {
-        return random.nextInt(lower);
+    public static int nextSecureInt(int lowerThan) {
+        SecureRandom sr = getSecureRandom();
+        synchronized (sr) {
+            return sr.nextInt(lowerThan);
+        }
     }
 
     /**

h2/src/main/org/h2/util/Resources.java

@@ -79,8 +79,4 @@ public class Resources {
         return data == null ? new byte[0] : data;
     }
 
-    static boolean isShutdown() {
-        return FILES == null;
-    }
-
 }

h2/src/main/org/h2/util/StringCache.java

@@ -120,8 +120,4 @@ public class StringCache {
         softCache = new SoftReference(null);
     }
 
-    static boolean isShutdown() {
-        return softCache == null;
-    }
-
 }

h2/src/main/org/h2/value/DataType.java

@@ -18,6 +18,7 @@ import java.sql.SQLException;
 import java.sql.Time;
 import java.sql.Timestamp;
 import java.sql.Types;
+import java.util.ArrayList;
 import java.util.HashMap;
 
 import org.h2.constant.ErrorCode;
@@ -27,7 +28,6 @@ import org.h2.jdbc.JdbcBlob;
 import org.h2.jdbc.JdbcClob;
 import org.h2.jdbc.JdbcConnection;
 import org.h2.message.Message;
-import org.h2.util.ObjectArray;
 import org.h2.util.ObjectUtils;
 import org.h2.util.StringUtils;
 
@@ -49,9 +49,13 @@ public class DataType {
      */
     public static final int TYPE_DATALINK = 70;
 
-    private static final ObjectArray TYPES = new ObjectArray();
+    /**
+     * The list of types. An ArrayList so that Tomcat doesn't set it to null
+     * when clearing references.
+     */
+    private static final ArrayList TYPES = new ArrayList();
     private static final HashMap TYPES_BY_NAME = new HashMap();
-    private static final DataType[] TYPES_BY_VALUE_TYPE = new DataType[Value.TYPE_COUNT];
+    private static final ArrayList TYPES_BY_VALUE_TYPE = new ArrayList();
 
     /**
      * The value type of this data type.
@@ -160,6 +164,9 @@ public class DataType {
     public int memory;
 
     static {
+        for (int i = 0; i < Value.TYPE_COUNT; i++) {
+            TYPES_BY_VALUE_TYPE.add(null);
+        }
         //## Java 1.4 begin ##
         if (TYPE_BOOLEAN != Types.BOOLEAN) {
             new Exception("Types.BOOLEAN: " + Types.BOOLEAN).printStackTrace();
@@ -318,8 +325,8 @@ public class DataType {
                 new String[]{"RESULT_SET"},
                 20
         );
-        for (int i = 0; i < TYPES_BY_VALUE_TYPE.length; i++) {
-            DataType dt = TYPES_BY_VALUE_TYPE[i];
+        for (int i = 0; i < TYPES_BY_VALUE_TYPE.size(); i++) {
+            DataType dt = (DataType) TYPES_BY_VALUE_TYPE.get(i);
             if (dt == null) {
                 Message.throwInternalError("unmapped type " + i);
             }
@@ -357,8 +364,8 @@ public class DataType {
                 }
             }
             TYPES_BY_NAME.put(dt.name, dt);
-            if (TYPES_BY_VALUE_TYPE[type] == null) {
-                TYPES_BY_VALUE_TYPE[type] = dt;
+            if (TYPES_BY_VALUE_TYPE.get(type) == null) {
+                TYPES_BY_VALUE_TYPE.set(type, dt);
             }
             TYPES.add(dt);
         }
@@ -411,7 +418,7 @@ public class DataType {
      *
      * @return the list
      */
-    public static ObjectArray getTypes() {
+    public static ArrayList getTypes() {
         return TYPES;
     }
 
@@ -639,9 +646,9 @@ public class DataType {
      * @return the data type object
      */
     public static DataType getDataType(int type) {
-        DataType dt = TYPES_BY_VALUE_TYPE[type];
+        DataType dt = (DataType) TYPES_BY_VALUE_TYPE.get(type);
         if (dt == null) {
-            dt = TYPES_BY_VALUE_TYPE[Value.NULL];
+            dt = (DataType) TYPES_BY_VALUE_TYPE.get(Value.NULL);
         }
         return dt;
     }

h2/src/main/org/h2/value/Value.java

@@ -329,8 +329,11 @@ public abstract class Value {
      */
     static Value cache(Value v) {
         if (SysProperties.OBJECT_CACHE) {
-            Value[] cache = (Value[]) softCache.get();
             int hash = v.hashCode();
+            if (softCache == null) {
+                softCache = new SoftReference(null);
+            }
+            Value[] cache = (Value[]) softCache.get();
             if (cache == null) {
                 cache = new Value[SysProperties.OBJECT_CACHE_SIZE];
                 softCache = new SoftReference(cache);

h2/src/main/org/h2/value/ValueBoolean.java

@@ -25,8 +25,11 @@ public class ValueBoolean extends Value {
      */
     public static final int DISPLAY_SIZE = 5;
 
-    private static final ValueBoolean TRUE = new ValueBoolean(true);
-    private static final ValueBoolean FALSE = new ValueBoolean(false);
+    /**
+     * Of type Object so that Tomcat doesn't set it to null.
+     */
+    private static final Object TRUE = new ValueBoolean(true);
+    private static final Object FALSE = new ValueBoolean(false);
 
     private final Boolean value;
 
@@ -47,7 +50,7 @@ public class ValueBoolean extends Value {
     }
 
     public Value negate() {
-        return value.booleanValue() ? FALSE : TRUE;
+        return (ValueBoolean) (value.booleanValue() ? FALSE : TRUE);
     }
 
     public Boolean getBoolean() {
@@ -83,7 +86,7 @@ public class ValueBoolean extends Value {
      * @return the value
      */
     public static ValueBoolean get(boolean b) {
-        return b ? TRUE : FALSE;
+        return (ValueBoolean) (b ? TRUE : FALSE);
     }
 
     public int getDisplaySize() {

h2/src/main/org/h2/value/ValueDecimal.java

@@ -38,8 +38,8 @@ public class ValueDecimal extends Value {
     private static final int DIVIDE_SCALE_ADD = 25;
     private static final BigDecimal DEC_ZERO = new BigDecimal("0");
     private static final BigDecimal DEC_ONE = new BigDecimal("1");
-    private static final ValueDecimal ZERO = new ValueDecimal(DEC_ZERO);
-    private static final ValueDecimal ONE = new ValueDecimal(DEC_ONE);
+    private static final Object ZERO = new ValueDecimal(DEC_ZERO);
+    private static final Object ONE = new ValueDecimal(DEC_ONE);
 
     private final BigDecimal value;
     private String valueString;
@@ -187,9 +187,9 @@ public class ValueDecimal extends Value {
      */
     public static ValueDecimal get(BigDecimal dec) {
         if (DEC_ZERO.equals(dec)) {
-            return ZERO;
+            return (ValueDecimal) ZERO;
         } else if (DEC_ONE.equals(dec)) {
-            return ONE;
+            return (ValueDecimal) ONE;
         }
         // TODO value optimization: find a way to read size of BigDecimal,
         // check max cache size

h2/src/test/org/h2/test/TestAll.java

@@ -102,6 +102,7 @@ import org.h2.test.synth.thread.TestMulti;
 import org.h2.test.unit.SelfDestructor;
 import org.h2.test.unit.TestBitField;
 import org.h2.test.unit.TestCache;
+import org.h2.test.unit.TestClearReferences;
 import org.h2.test.unit.TestCompress;
 import org.h2.test.unit.TestDataPage;
 import org.h2.test.unit.TestDate;
@@ -282,6 +283,9 @@ java org.h2.test.TestAll timer
 
 /*
 
+include ClearReferences test case
+isShutdown
+
 PageStore.switchLogIfPossible()
 
 drop table test;
@@ -609,6 +613,7 @@ http://www.w3schools.com/sql/
     private void testUnit() {
         new TestBitField().runTest(this);
         new TestCache().runTest(this);
+        new TestClearReferences().runTest(this);
         new TestCompress().runTest(this);
         new TestDataPage().runTest(this);
         new TestDate().runTest(this);

h2/src/test/org/h2/test/synth/TestRandomSQL.java

@@ -165,17 +165,20 @@ public class TestRandomSQL extends TestBase {
     }
 
     public void testCase(int i) throws SQLException {
-        String old = SysProperties.scriptDirectory;
-        SysProperties.scriptDirectory = "dataScript/";
-        seed = i;
-        printTime("seed: " + seed);
+        String old = SysProperties.getScriptDirectory();
         try {
-            deleteDb();
-        } catch (SQLException e) {
-            processException("deleteDb", e);
+            SysProperties.setScriptDirectory("dataScript/");
+            seed = i;
+            printTime("seed: " + seed);
+            try {
+                deleteDb();
+            } catch (SQLException e) {
+                processException("deleteDb", e);
+            }
+            testWithSeed(bnf);
+        } finally {
+            SysProperties.setScriptDirectory(old);
         }
-        testWithSeed(bnf);
-        SysProperties.scriptDirectory = old;
         try {
             deleteDb();
         } catch (SQLException e) {

h2/src/test/org/h2/test/todo/supportTemplates.txt

@@ -52,6 +52,7 @@ I am sorry to say that, but it looks like a corruption problem. I am very intere
 
 - Could you send the full stack trace of the exception including message text?
 - What is your database URL?
+- Do you use Tomcat or another web server? Do you unload or reload the web application?
 - You can find out if the database is corrupted when running
     SCRIPT TO 'test.sql'
 - What version H2 are you using?

h2/src/test/org/h2/test/unit/TestCache.java

@@ -19,6 +19,15 @@ import org.h2.test.TestBase;
  */
 public class TestCache extends TestBase {
 
+    /**
+     * Run just this test.
+     *
+     * @param a ignored
+     */
+    public static void main(String[] a) throws Exception {
+        TestBase.createCaller().init().test();
+    }
+
     public void test() throws SQLException {
         if (config.memory) {
             return;

h2/src/test/org/h2/test/unit/TestClearReferences.java

+package org.h2.test.unit;
+
+import java.io.File;
+import java.lang.reflect.Field;
+import java.lang.reflect.Modifier;
+import java.util.ArrayList;
+import org.h2.test.TestBase;
+
+/**
+ * Tests if Tomcat would clear static fields when re-loading a web application.
+ * See also
+ * http://svn.apache.org/repos/asf/tomcat/trunk/java/org/apache/catalina
+ * /loader/WebappClassLoader.java
+ */
+public class TestClearReferences extends TestBase {
+
+    private static final String[] KNOWN_REFRESHED = {
+        "org.h2.util.DateTimeUtils.cachedCalendar",
+        "org.h2.util.StringCache.softCache",
+        "org.h2.value.Value.softCache",
+        "org.h2.jdbcx.JdbcDataSourceFactory.cachedTraceSystem",
+        "org.h2.compress.CompressLZF.cachedHashTable",
+        "org.h2.store.fs.FileObjectMemory.cachedCompressedEmptyBlock",
+        "org.h2.tools.CompressTool.cachedBuffer",
+        "org.h2.util.MemoryUtils.reserveMemory",
+        "org.h2.util.NetUtils.cachedLocalAddress",
+        "org.h2.util.RandomUtils.cachedSecureRandom"
+    };
+
+    private boolean hasError;
+
+    /**
+     * Run just this test.
+     *
+     * @param a ignored
+     */
+    public static void main(String[] a) throws Exception {
+        TestBase.createCaller().init().test();
+    }
+
+    public void test() throws Exception {
+        String baseDir = "bin/org/h2";
+        ArrayList classes = new ArrayList();
+        check(classes, new File(baseDir));
+        for (int i = 0; i < classes.size(); i++) {
+            Class clazz = (Class) classes.get(i);
+            clearClass(clazz);
+        }
+        if (hasError) {
+            fail("Tomcat may clear the field above when reloading the web app");
+        }
+    }
+
+    private void check(ArrayList classes, File file) {
+        String name = file.getName();
+        if (file.isDirectory()) {
+            if (name.equals("CVS") || name.equals(".svn")) {
+                return;
+            }
+            File[] list = file.listFiles();
+            for (int i = 0; i < list.length; i++) {
+                check(classes, list[i]);
+            }
+        } else {
+            if (!name.endsWith(".class")) {
+                return;
+            }
+            String className = file.getAbsolutePath().replace('\\', '/');
+            className = className.substring(className.lastIndexOf("org/h2"));
+            String packageName = className.substring(0, className.lastIndexOf('/'));
+            if (!new File("src/main/" + packageName).exists()) {
+                return;
+            }
+            className = className.replace('/', '.');
+            className = className.substring(0, className.length() - ".class".length());
+            Class clazz = null;
+            try {
+                clazz = Class.forName(className);
+            } catch (ClassNotFoundException e) {
+                System.out.println("Could not load " + className + ": " + e.toString());
+            }
+            if (clazz != null) {
+                classes.add(clazz);
+            }
+        }
+    }
+
+    /**
+     * This is how Tomcat resets the fields as of 2009-01-30.
+     *
+     * @param clazz the class to clear
+     */
+    private void clearClass(Class clazz) throws Exception {
+        Field[] fields = clazz.getDeclaredFields();
+        for (int i = 0; i < fields.length; i++) {
+            Field field = fields[i];
+            if (field.getType().isPrimitive() || field.getName().indexOf("$") != -1) {
+                continue;
+            }
+            int modifiers = field.getModifiers();
+            if (!Modifier.isStatic(modifiers)) {
+                continue;
+            }
+            field.setAccessible(true);
+            Object o = field.get(null);
+            if (o == null) {
+                continue;
+            }
+            if (Modifier.isFinal(modifiers)) {
+                if (field.getType().getName().startsWith("java.")) {
+                    continue;
+                }
+                if (field.getType().getName().startsWith("javax.")) {
+                    continue;
+                }
+                clearInstance(o);
+            } else {
+                clearField(clazz.getName() + "." + field.getName() + " = " + o);
+            }
+        }
+    }
+
+    protected void clearInstance(Object instance) throws Exception {
+        Field[] fields = instance.getClass().getDeclaredFields();
+        for (int i = 0; i < fields.length; i++) {
+            Field field = fields[i];
+            if (field.getType().isPrimitive() || (field.getName().indexOf("$") != -1)) {
+                continue;
+            }
+            int modifiers = field.getModifiers();
+            if (Modifier.isStatic(modifiers) && Modifier.isFinal(modifiers)) {
+                continue;
+            }
+            field.setAccessible(true);
+            Object o = field.get(instance);
+            if (o == null) {
+                continue;
+            }
+            clearField(instance.getClass().getName() + "." + field.getName() + " = " + o);
+        }
+    }
+
+    private void clearField(String s) {
+        for (int i = 0; i < KNOWN_REFRESHED.length; i++) {
+            if (s.startsWith(KNOWN_REFRESHED[i])) {
+                return;
+            }
+        }
+        hasError = true;
+        System.out.println(s);
+    }
+
+}