Make fields final where appropriate.

Found by UCDetector, which seems to have gotten smarter recently.

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

@@ -30,9 +30,9 @@ import org.h2.value.ValueBoolean;
 public class ExpressionColumn extends Expression {
 
     private final Database database;
-    private String schemaName;
-    private String tableAlias;
-    private String columnName;
+    private final String schemaName;
+    private final String tableAlias;
+    private final String columnName;
     private ColumnResolver columnResolver;
     private int queryLevel;
     private Column column;
@@ -41,6 +41,9 @@ public class ExpressionColumn extends Expression {
     public ExpressionColumn(Database database, Column column) {
         this.database = database;
         this.column = column;
+        this.schemaName = null;
+        this.tableAlias = null;
+        this.columnName = null;
     }
 
     public ExpressionColumn(Database database, String schemaName, String tableAlias, String columnName) {

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

@@ -20,7 +20,7 @@ import org.h2.value.ValueArray;
  */
 public class ExpressionList extends Expression {
 
-    private Expression[] list;
+    private final Expression[] list;
 
     public ExpressionList(Expression[] list) {
         this.list = list;

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

@@ -30,7 +30,7 @@ public class JavaAggregate extends Expression {
 
     private final UserAggregate userAggregate;
     private final Select select;
-    private Expression[] args;
+    private final Expression[] args;
     private int[] argTypes;
     private int dataType;
     private Connection userConnection;

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

@@ -26,7 +26,7 @@ public class JavaFunction extends Expression implements FunctionCall {
 
     private final FunctionAlias functionAlias;
     private final FunctionAlias.JavaMethod javaMethod;
-    private Expression[] args;
+    private final Expression[] args;
 
     public JavaFunction(FunctionAlias functionAlias, Expression[] args) {
         this.functionAlias = functionAlias;

h2/src/main/org/h2/index/PageBtree.java

@@ -73,7 +73,7 @@ public abstract class PageBtree extends Page {
     /**
      * The estimated memory used by this object.
      */
-    private int memoryEstimated;
+    private final int memoryEstimated;
 
     PageBtree(PageBtreeIndex index, int pageId, Data data) {
         this.index = index;

h2/src/main/org/h2/index/PageData.java

@@ -65,7 +65,7 @@ abstract class PageData extends Page {
      * The estimated heap memory used by this object, in number of double words
      * (4 bytes each).
      */
-    private int memoryEstimated;
+    private final int memoryEstimated;
 
     PageData(PageDataIndex index, int pageId, Data data) {
         this.index = index;

h2/src/main/org/h2/index/PageDataIndex.java

@@ -42,7 +42,7 @@ public class PageDataIndex extends PageIndex {
     private long rowCount;
     private HashSet<Row> delta;
     private int rowCountDiff;
-    private HashMap<Integer, Integer> sessionRowCount;
+    private final HashMap<Integer, Integer> sessionRowCount;
     private int mainIndexColumn = -1;
     private DbException fastDuplicateKeyException;
 
@@ -65,6 +65,8 @@ public class PageDataIndex extends PageIndex {
         if (multiVersion) {
             sessionRowCount = New.hashMap();
             isMultiVersion = true;
+        } else {
+            sessionRowCount = null;
         }
         tableData = table;
         this.store = database.getPageStore();

h2/src/main/org/h2/index/ScanIndex.java

@@ -35,7 +35,7 @@ public class ScanIndex extends BaseIndex {
     private ArrayList<Row> rows = New.arrayList();
     private final RegularTable tableData;
     private int rowCountDiff;
-    private HashMap<Integer, Integer> sessionRowCount;
+    private final HashMap<Integer, Integer> sessionRowCount;
     private HashSet<Row> delta;
     private long rowCount;
 
@@ -43,6 +43,8 @@ public class ScanIndex extends BaseIndex {
         initBaseIndex(table, id, table.getName() + "_DATA", columns, indexType);
         if (database.isMultiVersion()) {
             sessionRowCount = New.hashMap();
+        } else {
+            sessionRowCount = null;
         }
         tableData = table;
     }

h2/src/main/org/h2/index/TreeNode.java

@@ -36,7 +36,7 @@ class TreeNode {
     /**
      * The row.
      */
-    Row row;
+    final Row row;
 
     TreeNode(Row row) {
         this.row = row;

h2/src/main/org/h2/index/ViewIndex.java

@@ -41,10 +41,10 @@ public class ViewIndex extends BaseIndex {
     private final SmallLRUCache<IntArray, CostElement> costCache =
         SmallLRUCache.newInstance(Constants.VIEW_INDEX_CACHE_SIZE);
     private boolean recursive;
-    private int[] indexMasks;
+    private final int[] indexMasks;
     private String planSQL;
     private Query query;
-    private Session createSession;
+    private final Session createSession;
 
     public ViewIndex(TableView view, String querySQL, ArrayList<Parameter> originalParameters, boolean recursive) {
         initBaseIndex(view, 0, null, null, IndexType.createNonUnique(false));
@@ -53,6 +53,8 @@ public class ViewIndex extends BaseIndex {
         this.originalParameters = originalParameters;
         this.recursive = recursive;
         columns = new Column[0];
+        this.createSession = null;
+        this.indexMasks = null;
     }
 
     public ViewIndex(TableView view, ViewIndex index, Session session, int[] masks) {

h2/src/main/org/h2/jdbc/JdbcConnection.java

@@ -67,8 +67,8 @@ public class JdbcConnection extends TraceObject implements Connection {
 
     private static boolean keepOpenStackTrace;
 
-    private String url;
-    private String user;
+    private final String url;
+    private final String user;
 
     // ResultSet.HOLD_CURSORS_OVER_COMMIT
     private int holdability = 1;
@@ -83,7 +83,7 @@ public class JdbcConnection extends TraceObject implements Connection {
     private String catalog;
     private Statement executingStatement;
     private final CompareMode compareMode = CompareMode.getInstance(null, 0);
-    private CloseWatcher watcher;
+    private final CloseWatcher watcher;
     private int queryTimeoutCache = -1;
 
     /**
@@ -141,6 +141,7 @@ public class JdbcConnection extends TraceObject implements Connection {
         this.getQueryTimeout = clone.getQueryTimeout;
         this.getReadOnly = clone.getReadOnly;
         this.rollback = clone.rollback;
+        this.watcher = null;
     }
 
     /**
@@ -153,6 +154,7 @@ public class JdbcConnection extends TraceObject implements Connection {
         setTrace(trace, TraceObject.CONNECTION, id);
         this.user = user;
         this.url = url;
+        this.watcher = null;
     }
 
     private void closeOld() {

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

@@ -20,9 +20,9 @@ public class JdbcXid extends TraceObject implements Xid {
 
     private static final String PREFIX = "XID";
 
-    private int formatId;
-    private byte[] branchQualifier;
-    private byte[] globalTransactionId;
+    private final int formatId;
+    private final byte[] branchQualifier;
+    private final byte[] globalTransactionId;
 
     JdbcXid(JdbcDataSourceFactory factory, int id, String tid) {
         setTrace(factory.getTrace(), TraceObject.XID, id);

h2/src/main/org/h2/result/ResultColumn.java

@@ -18,52 +18,52 @@ public class ResultColumn {
     /**
      * The column alias.
      */
-    String alias;
+    final String alias;
 
     /**
      * The schema name or null.
      */
-    String schemaName;
+    final String schemaName;
 
     /**
      * The table name or null.
      */
-    String tableName;
+    final String tableName;
 
     /**
      * The column name or null.
      */
-    String columnName;
+    final String columnName;
 
     /**
      * The value type of this column.
      */
-    int columnType;
+    final int columnType;
 
     /**
      * The precision.
      */
-    long precision;
+    final long precision;
 
     /**
      * The scale.
      */
-    int scale;
+    final int scale;
 
     /**
      * The expected display size.
      */
-    int displaySize;
+    final int displaySize;
 
     /**
      * True if this is an autoincrement column.
      */
-    boolean autoIncrement;
+    final boolean autoIncrement;
 
     /**
      * True if this column is nullable.
      */
-    int nullable;
+    final int nullable;
 
     /**
      * Read an object from the given transfer object.

h2/src/main/org/h2/result/RowList.java

@@ -28,7 +28,8 @@ public class RowList {
     private FileStore file;
     private Data rowBuff;
     private ArrayList<Value> lobs;
-    private int memory, maxMemory;
+    private final int maxMemory;
+    private int memory;
     private boolean written;
     private boolean readUncached;
 
@@ -41,6 +42,8 @@ public class RowList {
         this.session = session;
         if (session.getDatabase().isPersistent()) {
             maxMemory = session.getDatabase().getMaxOperationMemory();
+        } else {
+            maxMemory = 0;
         }
     }
 

h2/src/main/org/h2/result/SimpleRow.java

@@ -17,7 +17,7 @@ public class SimpleRow implements SearchRow {
 
     private long key;
     private int version;
-    private Value[] data;
+    private final Value[] data;
     private int memory;
 
     public SimpleRow(Value[] data) {

h2/src/main/org/h2/security/AES.java

@@ -26,8 +26,8 @@ public class AES implements BlockCipher {
     private static final int[] RT1 = new int[256];
     private static final int[] RT2 = new int[256];
     private static final int[] RT3 = new int[256];
-    private int[] encKey = new int[44];
-    private int[] decKey = new int[44];
+    private final int[] encKey = new int[44];
+    private final int[] decKey = new int[44];
 
     private static int rot8(int x) {
         return (x >>> 8) | (x << 24);

h2/src/main/org/h2/server/TcpServerThread.java

@@ -44,7 +44,7 @@ import org.h2.value.ValueLobDb;
  */
 public class TcpServerThread implements Runnable {
 
-    protected Transfer transfer;
+    protected final Transfer transfer;
     private final TcpServer server;
     private Session session;
     private boolean stop;

h2/src/main/org/h2/server/web/DbColumn.java

@@ -19,18 +19,18 @@ class DbColumn {
     /**
      * The column name.
      */
-    String name;
+    final String name;
 
     /**
      * The quoted table name.
      */
-    String quotedName;
+    final String quotedName;
 
     /**
      * The data type name (including precision and the NOT NULL flag if
      * applicable).
      */
-    String dataType;
+    final String dataType;
 
     DbColumn(DbContents contents, ResultSet rs) throws SQLException {
         name = rs.getString("COLUMN_NAME");

h2/src/main/org/h2/server/web/DbTableOrView.java

@@ -21,22 +21,22 @@ public class DbTableOrView {
     /**
      * The schema this table belongs to.
      */
-    DbSchema schema;
+    final DbSchema schema;
 
     /**
      * The table name.
      */
-    String name;
+    final String name;
 
     /**
      * The quoted table name.
      */
-    String quotedName;
+    final String quotedName;
 
     /**
      * True if this represents a view.
      */
-    boolean isView;
+    final boolean isView;
 
     /**
      * The column list.

h2/src/main/org/h2/server/web/WebApp.java

@@ -69,7 +69,7 @@ public class WebApp {
     /**
      * The web server.
      */
-    protected WebServer server;
+    protected final WebServer server;
 
     /**
      * The session.

h2/src/main/org/h2/server/web/WebSession.java

@@ -36,7 +36,7 @@ class WebSession {
     /**
      * The session attribute map.
      */
-    HashMap<String, Object> map = New.hashMap();
+    final HashMap<String, Object> map = New.hashMap();
 
     /**
      * The current locale.

h2/src/main/org/h2/server/web/WebThread.java

@@ -35,7 +35,7 @@ import org.h2.util.Utils;
 class WebThread extends WebApp implements Runnable {
 
     protected OutputStream output;
-    protected Socket socket;
+    protected final Socket socket;
     private final Thread thread;
     private InputStream input;
     private int headerBytes;

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

@@ -106,7 +106,7 @@ public class MetaTable extends Table {
 
     private final int type;
     private final int indexColumn;
-    private MetaIndex metaIndex;
+    private final MetaIndex metaIndex;
 
     /**
      * Create a new metadata table.
@@ -515,6 +515,7 @@ public class MetaTable extends Table {
 
         if (indexColumnName == null) {
             indexColumn = -1;
+            metaIndex = null;
         } else {
             indexColumn = getColumn(indexColumnName).getColumnId();
             IndexColumn[] indexCols = IndexColumn.wrap(new Column[] { cols[indexColumn] });

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

@@ -58,7 +58,7 @@ public class RegularTable extends TableBase {
     private final ArrayList<Index> indexes = New.arrayList();
     private long lastModificationId;
     private boolean containsLargeObject;
-    private PageDataIndex mainIndex;
+    private final PageDataIndex mainIndex;
     private int changesSinceAnalyze;
     private int nextAnalyze;
     private Column rowIdColumn;
@@ -86,6 +86,7 @@ public class RegularTable extends TableBase {
                     data.create, data.session);
             scanIndex = mainIndex;
         } else {
+            mainIndex = null;
             scanIndex = new ScanIndex(this, data.id, IndexColumn.wrap(getColumns()), IndexType.createScan(data.persistData));
         }
         indexes.add(scanIndex);

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

@@ -107,7 +107,7 @@ public class Recover extends Tool implements DataHandler {
         /**
          * The count per page type.
          */
-        int[] pageTypeCount = new int[Page.TYPE_STREAM_DATA + 2];
+        final int[] pageTypeCount = new int[Page.TYPE_STREAM_DATA + 2];
 
         /**
          * The number of free pages.

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

@@ -28,13 +28,14 @@ import org.h2.util.Utils;
  */
 public class Server extends Tool implements Runnable, ShutdownHandler {
 
-    private Service service;
+    private final Service service;
     private Server web, tcp, pg;
     private ShutdownHandler shutdownHandler;
     private boolean started;
 
     public Server() {
         // nothing to do
+        this.service = null;
     }
 
     /**

h2/src/main/org/h2/upgrade/DbUpgrade.java

@@ -26,7 +26,7 @@ import org.h2.util.Utils;
  */
 public class DbUpgrade {
 
-    private static boolean upgradeClassesPresent;
+    private static final boolean upgradeClassesPresent;
     private static boolean scriptInTempDir;
     private static boolean deleteOldDb;
 

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

@@ -33,9 +33,9 @@ import org.h2.message.DbException;
 public class Permutations<T> {
 
     private final T[] in;
-    private T[] out;
+    private final T[] out;
     private final int n, m;
-    private int[] index;
+    private final int[] index;
     private boolean hasNext = true;
 
     private Permutations(T[] in, T[] out, int m) {

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

@@ -33,12 +33,12 @@ public class SourceCompiler {
     /**
      * The class name to source code map.
      */
-    HashMap<String, String> sources = New.hashMap();
+    final HashMap<String, String> sources = New.hashMap();
 
     /**
      * The class name to byte code map.
      */
-    HashMap<String, Class<?>> compiled = New.hashMap();
+    final HashMap<String, Class<?>> compiled = New.hashMap();
 
     private final String compileDir = Utils.getProperty("java.io.tmpdir", ".");
 

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

@@ -36,15 +36,17 @@ public class CompareMode {
 
     private static CompareMode lastUsed;
 
-    private static boolean canUseICU4J;
+    private static final boolean canUseICU4J;
 
     static {
+        boolean b = false;
         try {
             Class.forName("com.ibm.icu.text.Collator");
-            canUseICU4J = true;
+            b = true;
         } catch (Exception e) {
             // ignore
         }
+        canUseICU4J = b;
     }
 
     private final String name;

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

@@ -38,8 +38,8 @@ public class ValueLobDb extends Value implements Value.ValueClob, Value.ValueBlo
     private int hash;
 
     private LobStorage lobStorage;
-    private long lobId;
-    private byte[] hmac;
+    private final long lobId;
+    private final byte[] hmac;
 
     private byte[] small;
 
@@ -60,6 +60,8 @@ public class ValueLobDb extends Value implements Value.ValueClob, Value.ValueBlo
         this.type = type;
         this.small = small;
         this.precision = precision;
+        this.lobId = 0;
+        this.hmac = null;
     }
 
     /**

h2/src/tools/org/h2/build/indexer/HtmlConverter.java

@@ -14,8 +14,8 @@ import java.util.HashMap;
  */
 public class HtmlConverter {
 
-    private static HashMap<String, Character> charMap = new HashMap<String, Character>();
-    private static HashMap<Character, String> codeMap = new HashMap<Character, String>();
+    private static final HashMap<String, Character> charMap = new HashMap<String, Character>();
+    private static final HashMap<Character, String> codeMap = new HashMap<Character, String>();
 
     private static final String[] CHARS = { "quot:34", "amp:38", "lt:60", "gt:62", "nbsp:160", "iexcl:161", "cent:162",
             "pound:163", "curren:164", "yen:165", "brvbar:166", "sect:167", "uml:168", "copy:169", "ordf:170",

h2/src/tools/org/h2/build/indexer/Page.java

@@ -19,7 +19,7 @@ public class Page {
     /**
      * The file name.
      */
-    String fileName;
+    final String fileName;
 
     /**
      * The title of the page.

h2/src/tools/org/h2/build/indexer/Word.java

@@ -25,7 +25,7 @@ public class Word {
     /**
      * The pages map.
      */
-    HashMap<Page, Weight> pages = new HashMap<Page, Weight>();
+    final HashMap<Page, Weight> pages = new HashMap<Page, Weight>();
 
     private ArrayList<Weight> weightList;
 

h2/src/tools/org/h2/dev/ftp/server/FtpData.java

@@ -24,20 +24,22 @@ public class FtpData extends Thread {
     private final InetAddress address;
     private ServerSocket serverSocket;
     private volatile Socket socket;
-    private boolean active;
-    private int port;
+    private final boolean active;
+    private final int port;
 
     FtpData(FtpServer server, InetAddress address, ServerSocket serverSocket) {
         this.server = server;
         this.address = address;
         this.serverSocket = serverSocket;
+        this.port = 0;
+        this.active = false;
     }
 
     FtpData(FtpServer server, InetAddress address, int port) {
         this.server = server;
         this.address = address;
         this.port = port;
-        active = true;
+        this.active = true;
     }
 
     public void run() {

h2/src/tools/org/h2/dev/store/btree/Chunk.java

@@ -29,7 +29,7 @@ public class Chunk {
     /**
      * The chunk id.
      */
-    int id;
+    final int id;
 
     /**
      * The start position within the file.

h2/src/tools/org/h2/dev/store/btree/CursorPos.java

@@ -14,7 +14,7 @@ public class CursorPos {
     /**
      * The current page.
      */
-    public Page page;
+    public final Page page;
 
     /**
      * The current index.
@@ -24,7 +24,7 @@ public class CursorPos {
     /**
      * The position in the parent page, if any.
      */
-    public CursorPos parent;
+    public final CursorPos parent;
 
     public CursorPos(Page page, int index, CursorPos parent) {
         this.page = page;

h2/src/tools/org/h2/dev/store/btree/MVStoreBuilder.java

@@ -14,7 +14,7 @@ import org.h2.util.New;
  */
 public class MVStoreBuilder {
 
-    private HashMap<String, Object> config = New.hashMap();
+    private final HashMap<String, Object> config = New.hashMap();
 
     /**
      * Use the following file name. If the file does not exist, it is

h2/src/tools/org/h2/dev/store/btree/StreamStore.java

@@ -272,12 +272,12 @@ public class StreamStore {
      */
     static class Stream extends InputStream {
 
-        private StreamStore store;
+        private final StreamStore store;
         private byte[] oneByteBuffer;
         private ByteBuffer idBuffer;
         private ByteArrayInputStream buffer;
         private long skip;
-        private long length;
+        private final long length;
         private long pos;
 
         Stream(StreamStore store, byte[] id) {

h2/src/tools/org/h2/jaqu/bytecode/Operation.java

@@ -55,7 +55,7 @@ class Operation implements Token {
         DIVIDE("/"),
         MOD("%");
 
-        private String name;
+        private final String name;
 
         Type(String name) {
             this.name = name;

h2/src/tools/org/h2/jaqu/util/StatementLogger.java

@@ -21,7 +21,7 @@ import java.util.concurrent.atomic.AtomicLong;
 public class StatementLogger {
 
     public static boolean logStatements;
-    private static PrintWriter out = new PrintWriter(System.out);
+    private static final PrintWriter out = new PrintWriter(System.out);
     private static final AtomicLong SELECT_COUNT = new AtomicLong();
     private static final AtomicLong CREATE_COUNT = new AtomicLong();
     private static final AtomicLong INSERT_COUNT = new AtomicLong();