add some javadoc

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

@@ -6941,7 +6941,7 @@ public class Parser {
     }
 
     /**
-     * Checks the table is the DUAL special table.
+     * Is this the Oracle DUAL table or the IBM/DB2 SYSIBM table?
      *
      * @param tableName table name.
      * @return {@code true} if the table is DUAL special table. Otherwise returns {@code false}.

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

@@ -256,7 +256,7 @@ public class Console extends Tool implements ShutdownHandler {
     }
 
     /**
-     * Overriden by GUIConsole to show a window
+     * Overridden by GUIConsole to show a window
      */
     void show() {
     }

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

@@ -172,6 +172,15 @@ public class StringUtils {
         return buff.toString();
     }
 
+    /**
+     * Convert a string to a Java literal using the correct escape sequences.
+     * The literal is not enclosed in double quotes. The result can be used in
+     * properties files or in Java source code.
+     * 
+     * @param s the text to convert
+     * @param buff the Java representation to return
+     * @param forSQL true if we embedding this inside a STRINGDECODE SQL command
+     */
     public static void javaEncode(String s, StringBuilder buff, boolean forSQL) {
         int length = s.length();
         for (int i = 0; i < length; i++) {

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

@@ -132,6 +132,9 @@ public final class ExtTypeInfoEnum extends ExtTypeInfo {
         return enumerators[ordinal];
     }
 
+    /**
+     * Get ValueEnum instance for an ordinal.
+     */
     public ValueEnum getValue(int ordinal) {
         if (ordinal < 0 || ordinal >= enumerators.length) {
             throw DbException.get(ErrorCode.ENUM_VALUE_NOT_PERMITTED, enumerators.toString(),
@@ -140,6 +143,9 @@ public final class ExtTypeInfoEnum extends ExtTypeInfo {
         return new ValueEnum(this, enumerators[ordinal], ordinal);
     }
 
+    /**
+     * Get ValueEnum instance for a label string.
+     */
     public ValueEnum getValue(String label) {
         ValueEnum value = getValueOrNull(label);
         if (value == null) {

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

@@ -82,7 +82,7 @@ public class ValueInterval extends Value {
      * @param scale
      *            fractional seconds precision. Ignored if specified type of
      *            interval does not have seconds.
-     * @return displayed size.
+     * @return display size
      */
     public static int getDisplaySize(int type, int precision, int scale) {
         switch (type) {