OPENJPA-182. Moved to API-based model. Query.setHint() can still be used via the query hint => fetch plan binding.

Removed the logic to override the forUpdate value, since the calling code already incorporates fetch configuration data into its decision about how to invoke toSelect(). Added a test case to assert this behavior.

Also cleaned up some minor whitespace issues, and reduced code duplication by moving a couple of concepts up into DBDictionary. Removed some seemingly-unnecessary overrides from H2Dictionary.

Added a test case for isolation level configuration. For non-DB2 dictionaries, it asserts that an exception is thrown during execution. Someone with DB2 knowledge / access should fill in the test case for the DB2 cases. As we add support for per-query isolation level configuration for other databases, we should change this test case.

git-svn-id: https://svn.apache.org/repos/asf/incubator/openjpa/trunk@525997 13f79535-47bb-0310-9956-ffa450edef68

openjpa-jdbc/src/main/java/org/apache/openjpa/jdbc/kernel/DelegatingJDBCFetchConfiguration.java

@@ -240,4 +240,21 @@ public class DelegatingJDBCFetchConfiguration
             throw translate(re);
         }
     }
+
+    public int getIsolationLevel() {
+        try {
+            return getJDBCDelegate().getIsolationLevel();
+        } catch (RuntimeException re) {
+            throw translate(re);
+        }
+    }
+
+    public JDBCFetchConfiguration setIsolationLevel(int level) {
+        try {
+            getJDBCDelegate().setIsolationLevel(level);
+            return this;
+        } catch (RuntimeException re) {
+            throw translate(re);
+        }
+    }
 }

openjpa-jdbc/src/main/java/org/apache/openjpa/jdbc/kernel/JDBCFetchConfiguration.java

@@ -16,6 +16,7 @@
 package org.apache.openjpa.jdbc.kernel;
 
 import java.sql.ResultSet;
+import java.sql.Connection;
 import java.util.Collection;
 import java.util.Set;
 
@@ -169,4 +170,38 @@ public interface JDBCFetchConfiguration
      * Convenience method to cast traversal to store-specific type.
      */
     public JDBCFetchConfiguration traverseJDBC(FieldMetaData fm);
+
+    /**
+     * <p>The isolation level for queries issued to the database. This overrides
+     * the persistence-unit-wide <code>openjpa.jdbc.TransactionIsolation</code>
+     * value.</p>
+     *
+     * <p>Must be one of {@link Connection#TRANSACTION_NONE},
+     * {@link Connection#TRANSACTION_READ_UNCOMMITTED},
+     * {@link Connection#TRANSACTION_READ_COMMITTED},
+     * {@link Connection#TRANSACTION_REPEATABLE_READ},
+     * {@link Connection#TRANSACTION_SERIALIZABLE},
+     * or -1 for the default connection level specified by the context in
+     * which this fetch configuration is being used.</p>
+     *
+     * @since 0.9.7
+     */
+    public int getIsolationLevel();
+
+    /**
+     * <p>The isolation level for queries issued to the database. This overrides
+     * the persistence-unit-wide <code>openjpa.jdbc.TransactionIsolation</code>
+     * value.</p>
+     *
+     * <p>Must be one of {@link Connection#TRANSACTION_NONE},
+     * {@link Connection#TRANSACTION_READ_UNCOMMITTED},
+     * {@link Connection#TRANSACTION_READ_COMMITTED},
+     * {@link Connection#TRANSACTION_REPEATABLE_READ},
+     * {@link Connection#TRANSACTION_SERIALIZABLE},
+     * or -1 for the default connection level specified by the context in
+     * which this fetch configuration is being used.</p>
+     *
+     * @since 0.9.7
+     */
+    public JDBCFetchConfiguration setIsolationLevel(int level);
 }

openjpa-jdbc/src/main/java/org/apache/openjpa/jdbc/kernel/JDBCFetchConfigurationImpl.java

@@ -17,6 +17,7 @@ package org.apache.openjpa.jdbc.kernel;
 
 import java.io.Serializable;
 import java.sql.ResultSet;
+import java.sql.Connection;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashSet;
@@ -65,6 +66,7 @@ public class JDBCFetchConfigurationImpl
         public int size = 0;
         public int syntax = 0;
         public Set joins = null;
+        public int isolationLevel = -1;
     }
 
     private final JDBCConfigurationState _state;
@@ -319,4 +321,22 @@ public class JDBCFetchConfigurationImpl
             return null;
         return (JDBCConfiguration) conf;
     }
+
+    public int getIsolationLevel() {
+        return _state.isolationLevel;
+    }
+
+    public JDBCFetchConfiguration setIsolationLevel(int level) {
+        if (level != -1
+            && level != Connection.TRANSACTION_NONE
+            && level != Connection.TRANSACTION_READ_UNCOMMITTED
+            && level != Connection.TRANSACTION_READ_COMMITTED
+            && level != Connection.TRANSACTION_REPEATABLE_READ
+            && level != Connection.TRANSACTION_SERIALIZABLE)
+            throw new IllegalArgumentException(
+                _loc.get("bad-level", Integer.valueOf(level)).getMessage());
+        
+        _state.isolationLevel = level;
+        return this;
+    }
 }

openjpa-jdbc/src/main/java/org/apache/openjpa/jdbc/sql/DB2Dictionary.java

@@ -23,8 +23,8 @@ import java.util.Arrays;
 import java.util.StringTokenizer;
 import org.apache.openjpa.jdbc.kernel.JDBCFetchConfiguration;
 import org.apache.openjpa.jdbc.schema.Sequence;
-import org.apache.openjpa.lib.log.Log;
 import org.apache.openjpa.util.OpenJPAException;
+import org.apache.openjpa.kernel.LockLevels;
 
 /**
  * Dictionary for IBM DB2 database.
@@ -35,19 +35,20 @@ public class DB2Dictionary
     public String optimizeClause = "optimize for";
     public String rowClause = "row";
     private int db2ServerType = 0;
-    private static final int  db2ISeriesV5R3AndEarlier = 1;
+    private static final int db2ISeriesV5R3AndEarlier = 1;
     private static final int db2UDBV81OrEarlier = 2;
     private static final int db2ZOSV8x = 3;
     private static final int db2UDBV82AndLater = 4;
-    private static final int  db2ISeriesV5R4AndLater = 5;
+    private static final int db2ISeriesV5R4AndLater = 5;
-	private static final String  forUpdateOfClause="FOR UPDATE OF";
+	private static final String forUpdateOfClause = "FOR UPDATE OF";
-    private static final String  withRSClause="WITH RS";
+    private static final String withRSClause = "WITH RS";
-    private static final String  withRRClause="WITH RR";
+    private static final String withRRClause = "WITH RR";
-    private static final String  useKeepUpdateLockClause= "USE AND KEEP UPDATE LOCKS";
+    private static final String useKeepUpdateLockClause
-    private static final String  useKeepExclusiveLockClause="USE AND KEEP EXCLUSIVE LOCKS";
+        = "USE AND KEEP UPDATE LOCKS";
-    private static final String  forReadOnlyClause = "FOR READ ONLY";
+    private static final String useKeepExclusiveLockClause
-    public static final String UPDATE_HINT = "openjpa.hint.updateClause";
+        = "USE AND KEEP EXCLUSIVE LOCKS";
-    public static final String ISOLATION_HINT = "openjpa.hint.isolationLevel";
+    private static final String forReadOnlyClause = "FOR READ ONLY";
+
     public DB2Dictionary() {
         platform = "DB2";
         validationSQL = "SELECT DISTINCT(CURRENT TIMESTAMP) FROM "
@@ -189,15 +190,15 @@ public class DB2Dictionary
 
 	    	// Determine the type of DB2 database
 	    	if (isDB2ISeriesV5R3AndEarlier(metaData))
-	    	    db2ServerType =db2ISeriesV5R3AndEarlier;
+	    	    db2ServerType = db2ISeriesV5R3AndEarlier;
 	    	else if (isDB2UDBV81OrEarlier(metaData,maj,min))
-	    	    db2ServerType =db2UDBV81OrEarlier;
+	    	    db2ServerType = db2UDBV81OrEarlier;
 	    	else if (isDB2ZOSV8x(metaData,maj))
-	    	    db2ServerType =db2ZOSV8x;
+	    	    db2ServerType = db2ZOSV8x;
 	    	else if (isDB2UDBV82AndLater(metaData,maj,min))
-	    	    db2ServerType=db2UDBV82AndLater;
+	    	    db2ServerType = db2UDBV82AndLater;
 	    	else if (isDB2ISeriesV5R4AndLater(metaData))
-	    	    db2ServerType=db2ISeriesV5R4AndLater;
+	    	    db2ServerType = db2ISeriesV5R4AndLater;
 
 	    	if (maj >= 9 || (maj == 8 && min >= 2)) {
 	    		supportsLockingWithMultipleTables = true;
@@ -226,65 +227,63 @@ public class DB2Dictionary
         }
     }
 
-    /** Get the update clause for the query based on the 
+    /**
+     * Get the update clause for the query based on the
      * updateClause and isolationLevel hints
      */
-    public String getForUpdateClause(JDBCFetchConfiguration fetch, boolean forUpdate) {
+    protected String getForUpdateClause(JDBCFetchConfiguration fetch,
-        String isolationLevel = null;
+        boolean forUpdate) {
-        boolean updateClause;
+        int isolationLevel;
-        DatabaseMetaData metaData = null;
         StringBuffer forUpdateString = new StringBuffer();
         try {
-            // Determine the update clause/isolationLevel the hint 
+            // Determine the isolationLevel; the fetch
-            // overrides the persistence.xml value
+            // configuration data overrides the persistence.xml value
-            if (fetch != null && fetch.getHint(UPDATE_HINT)
+            if (fetch != null && fetch.getIsolationLevel() != -1)
-                !=null )
+                isolationLevel = fetch.getIsolationLevel();
-                updateClause = ((Boolean)fetch.
-                getHint(UPDATE_HINT)).booleanValue();
             else
-                updateClause = forUpdate;
+                isolationLevel = conf.getTransactionIsolationConstant();
-            if (fetch != null &&fetch.getHint(ISOLATION_HINT)
+
-                !=null )
+            if (!forUpdate) {
-                isolationLevel = (String)fetch.
-                getHint(ISOLATION_HINT);
-            else 
-                isolationLevel = conf.getTransactionIsolation();
-            if (updateClause == false)
                 // This sql is not for update so add FOR Read Only clause
                 forUpdateString.append(" ").append(forReadOnlyClause)
                     .append(" ");
-            else if (updateClause == true){
+            } else {
 
-                switch(db2ServerType){
+                switch(db2ServerType) {
                 case db2ISeriesV5R3AndEarlier:
                 case db2UDBV81OrEarlier:
-                    if (isolationLevel.equals("read-uncommitted"))
+                    if (isolationLevel ==
+                        Connection.TRANSACTION_READ_UNCOMMITTED) {
                         forUpdateString.append(" ").append(withRSClause)
-                        .append(" ").append(forUpdateOfClause).append(" ");
+                            .append(" ").append(forUpdateOfClause).append(" ");
-                    else
+                    } else {
                         forUpdateString.append(" ").append(forUpdateOfClause)
-                        .append(" ");
+                           .append(" ");
+                    }
                     break;
                 case db2ZOSV8x:
                 case db2UDBV82AndLater:
-                    if (isolationLevel.equals("serializable"))
+                    if (isolationLevel == Connection.TRANSACTION_SERIALIZABLE) {
                         forUpdateString.append(" ").append(withRRClause)
-                        .append(" ").append(useKeepUpdateLockClause)
+                            .append(" ").append(useKeepUpdateLockClause)
-                        .append(" ");
+                            .append(" ");
-                    else
+                    } else {
                         forUpdateString.append(" ").append(withRSClause)
-                        .append(" ").append(useKeepUpdateLockClause)
+                            .append(" ").append(useKeepUpdateLockClause)
-                        .append(" ");	
+                            .append(" ");
+                    }
                     break;
                 case db2ISeriesV5R4AndLater:
-                    if (isolationLevel.equals("serializable"))
+                    if (isolationLevel == Connection.TRANSACTION_SERIALIZABLE) {
                         forUpdateString.append(" ").append(withRRClause)
-                        .append(" ").append(useKeepExclusiveLockClause)
+                            .append(" ").append(useKeepExclusiveLockClause)
-                        .append(" ");
+                            .append(" ");
-                    else
+                    } else {
                         forUpdateString.append(" ").append(withRSClause)
-                        .append(" ").append(useKeepExclusiveLockClause)
+                            .append(" ").append(useKeepExclusiveLockClause)
-                        .append(" ");	
+                            .append(" ");
+                    }
+                    break;
                 }
             }
         }
@@ -299,16 +298,16 @@ public class DB2Dictionary
         int min) throws SQLException {
         boolean match = false;
         if (metadata.getDatabaseProductVersion().indexOf("SQL") != -1
-            && ((maj ==8 && min >=2) ||(maj >=8)))
+            && ((maj == 8 && min >= 2) ||(maj >= 8)))
             match = true;
         return match;
     }
 
-    public boolean isDB2ZOSV8x(DatabaseMetaData metadata,int maj)
+    public boolean isDB2ZOSV8x(DatabaseMetaData metadata, int maj)
        throws SQLException {
        boolean match = false;
        if (metadata.getDatabaseProductVersion().indexOf("DSN") != -1
-           && maj ==8 )
+           && maj == 8)
            match = true;
         return match;
     }
@@ -318,7 +317,7 @@ public class DB2Dictionary
        boolean match = false;
        if (metadata.getDatabaseProductVersion().indexOf("AS") != -1
            && generateVersionNumber(metadata.getDatabaseProductVersion())
-           <= 530 )
+           <= 530)
            match = true;
        return match;
     }
@@ -328,16 +327,16 @@ public class DB2Dictionary
        boolean match = false;
        if (metadata.getDatabaseProductVersion().indexOf("AS") != -1
            && generateVersionNumber(metadata.getDatabaseProductVersion())
-           >= 540 )
+           >= 540)
            match = true;
       return match;
     }
 
-    public boolean isDB2UDBV81OrEarlier(DatabaseMetaData metadata,int maj, 
+    public boolean isDB2UDBV81OrEarlier(DatabaseMetaData metadata, int maj,
         int min) throws SQLException {
         boolean match = false;
         if (metadata.getDatabaseProductVersion().indexOf("SQL") != -1 &&
-           ((maj ==8 && min <=1)|| maj <8 ))
+           ((maj == 8 && min <= 1)|| maj < 8))
             match = true;
         return match;
     }
@@ -359,71 +358,16 @@ public class DB2Dictionary
         return i;
     }
 
-       
-    /**
-     * Override the toOperationMethod of DBDictionary to pass the 
-     * forUpdateString.
-     */
-    protected SQLBuffer toOperation(String op, SQLBuffer selects, 
-        SQLBuffer from, SQLBuffer where, SQLBuffer group, SQLBuffer having, 
-        SQLBuffer order, boolean distinct, boolean forUpdate, long start, 
-        long end,String forUpdateString) {
-        SQLBuffer buf = new SQLBuffer(this);
-        buf.append(op);
-        boolean range = start != 0 || end != Long.MAX_VALUE;
-        if (range && rangePosition == RANGE_PRE_DISTINCT)
-            appendSelectRange(buf, start, end);
-        if (distinct)
-            buf.append(" DISTINCT");
-        if (range && rangePosition == RANGE_POST_DISTINCT)
-            appendSelectRange(buf, start, end);
-        buf.append(" ").append(selects).append(" FROM ").append(from);
-
-        if (where != null && !where.isEmpty())
-            buf.append(" WHERE ").append(where);
-        if (group != null && !group.isEmpty())
-            buf.append(" GROUP BY ").append(group);
-        if (having != null && !having.isEmpty()) {
-            assertSupport(supportsHaving, "SupportsHaving");
-            buf.append(" HAVING ").append(having);
-        }
-        if (order != null && !order.isEmpty())
-            buf.append(" ORDER BY ").append(order);
-        if (range && rangePosition == RANGE_POST_SELECT)
-            appendSelectRange(buf, start, end);
-
-        if (!simulateLocking ) {
-            assertSupport(supportsSelectForUpdate, "SupportsSelectForUpdate");
-            buf.append(" ").append(forUpdateString);
-        }
-        if (range && rangePosition == RANGE_POST_LOCK)
-            appendSelectRange(buf, start, end);
-        return buf;
-    }
-
     public SQLBuffer toSelect(Select sel, boolean forUpdate,
         JDBCFetchConfiguration fetch) {
-        sel.addJoinClassConditions();
+        SQLBuffer buf = super.toSelect(sel, forUpdate, fetch);
-        boolean update = forUpdate && sel.getFromSelect() == null;
+
-        SQLBuffer select = getSelects(sel, false, update);
+        if (sel.getExpectedResultCount() > 0) {
-        SQLBuffer ordering = null;
+            buf.append(" ").append(optimizeClause).append(" ")
-        if (!sel.isAggregate() || sel.getGrouping() != null)
+                .append(String.valueOf(sel.getExpectedResultCount()))
-            ordering = sel.getOrdering();
+                .append(" ").append(rowClause);
-        SQLBuffer from;
+        }
-        if (sel.getFromSelect() != null)
+
-            from = getFromSelect(sel, forUpdate);
-        else
-            from = getFrom(sel, update);
-        SQLBuffer where = getWhere(sel, update);
-        String forUpdateString = getForUpdateClause(fetch,forUpdate);
-        SQLBuffer buf = toOperation(getSelectOperation(fetch), select,
-            from, where,sel.getGrouping(), sel.getHaving(),  ordering,
-            sel.isDistinct(), forUpdate, sel.getStartIndex(),
-            sel.getEndIndex(),forUpdateString);
-        if (sel.getExpectedResultCount() > 0)
-            buf.append(" ").append(optimizeClause).append(" ").
-            append(String.valueOf(sel.getExpectedResultCount())).
-            append(" ").append(rowClause);
         return buf;
     }
 

openjpa-jdbc/src/main/java/org/apache/openjpa/jdbc/sql/DBDictionary.java

@@ -2145,7 +2145,22 @@ public class DBDictionary
         SQLBuffer having, SQLBuffer order,
         boolean distinct, boolean forUpdate, long start, long end) {
         return toOperation(getSelectOperation(fetch), selects, from, where,
-            group, having, order, distinct, forUpdate, start, end);
+            group, having, order, distinct, forUpdate, start, end,
+            getForUpdateClause(fetch, forUpdate));
+    }
+
+    /**
+     * Get the update clause for the query based on the
+     * updateClause and isolationLevel hints
+     */
+    protected String getForUpdateClause(JDBCFetchConfiguration fetch,
+        boolean forUpdate) {
+        if (fetch.getIsolationLevel() != -1)
+            throw new IllegalStateException(_loc.get(
+                "isolation-level-config-not-supported", getClass().getName())
+                .getMessage());
+        else
+            return forUpdateClause;
     }
 
     /**
@@ -2161,7 +2176,7 @@ public class DBDictionary
     protected SQLBuffer toOperation(String op, SQLBuffer selects,
         SQLBuffer from, SQLBuffer where, SQLBuffer group, SQLBuffer having,
         SQLBuffer order, boolean distinct, boolean forUpdate, long start,
-        long end) {
+        long end, String forUpdateClause) {
         SQLBuffer buf = new SQLBuffer(this);
         buf.append(op);
 
@@ -2190,8 +2205,8 @@ public class DBDictionary
 
         if (forUpdate && !simulateLocking) {
             assertSupport(supportsSelectForUpdate, "SupportsSelectForUpdate");
-            if (forUpdateClause != null)
+            if (this.forUpdateClause != null)
-                buf.append(" ").append(forUpdateClause);
+                buf.append(" ").append(this.forUpdateClause);
         }
         if (range && rangePosition == RANGE_POST_LOCK)
             appendSelectRange(buf, start, end);

openjpa-jdbc/src/main/java/org/apache/openjpa/jdbc/sql/H2Dictionary.java

@@ -159,14 +159,6 @@ public class H2Dictionary extends DBDictionary {
         return buf.toString();
     }
 
-    protected SQLBuffer toOperation(String op, SQLBuffer selects,
-        SQLBuffer from, SQLBuffer where, SQLBuffer group, SQLBuffer having,
-        SQLBuffer order, boolean distinct, boolean forUpdate, long start,
-        long end) {
-        return super.toOperation(op, selects, from, where, group, having,
-            order, distinct, forUpdate, start, end);
-    }
-
     public Column[] getColumns(DatabaseMetaData meta, String catalog,
         String schemaName, String tableName, String columnName, Connection conn)
         throws SQLException {
@@ -175,18 +167,6 @@ public class H2Dictionary extends DBDictionary {
         return cols;
     }
 
-    public void setDouble(PreparedStatement stmnt, int idx, double val,
-        Column col)
-        throws SQLException {
-        super.setDouble(stmnt, idx, val, col);
-    }
-
-    public void setBigDecimal(PreparedStatement stmnt, int idx, BigDecimal val,
-        Column col)
-        throws SQLException {
-        super.setBigDecimal(stmnt, idx, val, col);
-    }
-
     protected void appendSelectRange(SQLBuffer buf, long start, long end) {
         if (end != Long.MAX_VALUE)
             buf.append(" LIMIT ").appendValue(end - start);

openjpa-jdbc/src/main/java/org/apache/openjpa/jdbc/sql/HSQLDictionary.java

@@ -193,13 +193,13 @@ public class HSQLDictionary
     protected SQLBuffer toOperation(String op, SQLBuffer selects,
         SQLBuffer from, SQLBuffer where, SQLBuffer group, SQLBuffer having,
         SQLBuffer order, boolean distinct, boolean forUpdate, long start,
-        long end) {
+        long end, String forUpdateClause) {
         // hsql requires ordering when limit is used
         if ((start != 0 || end != Long.MAX_VALUE)
             && (order == null || order.isEmpty()))
             order = _oneBuffer;
         return super.toOperation(op, selects, from, where, group, having,
-            order, distinct, forUpdate, start, end);
+            order, distinct, forUpdate, start, end, forUpdateClause);
     }
 
     public Column[] getColumns(DatabaseMetaData meta, String catalog,

openjpa-jdbc/src/main/resources/org/apache/openjpa/jdbc/kernel/localizer.properties

@@ -97,3 +97,8 @@ clstable-seq-usage: Usage: \
 native-seq-usage: Usage: java org.apache.openjpa.jdbc.kernel.NativeJDBCSeq\n\
 	\t[-properties/-p <properties file or resource>]\n\
 	\t[-<property name> <property value>]*
+bad-level: Invalid isolation level. Valid levels are -1, \
+    Connection.TRANSACTION_NONE, Connection.TRANSACTION_READ_UNCOMMITTED, \ 
+    Connection.TRANSACTION_READ_COMMITTED, \
+    Connection.TRANSACTION_REPEATABLE_READ, or \
+    Connection.TRANSACTION_SERIALIZABLE. Specified value: {0}.

openjpa-jdbc/src/main/resources/org/apache/openjpa/jdbc/sql/localizer.properties

@@ -160,3 +160,5 @@ oracle-timestamp-bug: An ArrayIndexOutOfBoundsException has occured when \
     less than 9.2. Downgrading the driver will solve this, or it can be \
     worked around by setting the "SupportsTimestampNanos" DBDictionary \
     property to "true".
+isolation-level-config-not-supported: This DBDictionary does not support \
+    customization of isolation levels on a per-query basis. DBDictionary: {0}.

openjpa-persistence-jdbc/src/main/java/org/apache/openjpa/persistence/jdbc/JDBCFetchPlan.java

@@ -15,6 +15,8 @@
  */
 package org.apache.openjpa.persistence.jdbc;
 
+import java.sql.Connection;
+
 import org.apache.openjpa.jdbc.kernel.EagerFetchModes;
 import org.apache.openjpa.jdbc.kernel.LRSSizes;
 import org.apache.openjpa.jdbc.sql.JoinSyntaxes;
@@ -114,4 +116,38 @@ public interface JDBCFetchPlan
      * @see JoinSyntaxes
      */
     public JDBCFetchPlan setJoinSyntax(int syntax);
+
+    /**
+     * <p>The isolation level for queries issued to the database. This overrides
+     * the persistence-unit-wide <code>openjpa.jdbc.TransactionIsolation</code>
+     * value.</p>
+     *
+     * <p>Must be one of {@link Connection#TRANSACTION_NONE},
+     * {@link Connection#TRANSACTION_READ_UNCOMMITTED},
+     * {@link Connection#TRANSACTION_READ_COMMITTED},
+     * {@link Connection#TRANSACTION_REPEATABLE_READ}, 
+     * {@link Connection#TRANSACTION_SERIALIZABLE},
+     * or -1 for the default connection level specified by the context in
+     * which this fetch plan is being used.</p>
+     *
+     * @since 0.9.7
+     */
+    public int getIsolationLevel();
+
+    /**
+     * <p>The isolation level for queries issued to the database. This overrides
+     * the persistence-unit-wide <code>openjpa.jdbc.TransactionIsolation</code>
+     * value.</p>
+     *
+     * <p>Must be one of {@link Connection#TRANSACTION_NONE},
+     * {@link Connection#TRANSACTION_READ_UNCOMMITTED},
+     * {@link Connection#TRANSACTION_READ_COMMITTED},
+     * {@link Connection#TRANSACTION_REPEATABLE_READ},
+     * {@link Connection#TRANSACTION_SERIALIZABLE},
+     * or -1 for the default connection level specified by the context in
+     * which this fetch plan is being used.</p>
+     *
+     * @since 0.9.7
+     */
+    public JDBCFetchPlan setIsolationLevel(int level);
 }

openjpa-persistence-jdbc/src/main/java/org/apache/openjpa/persistence/jdbc/JDBCFetchPlanImpl.java

@@ -102,4 +102,13 @@ public class JDBCFetchPlanImpl
         _fetch.setJoinSyntax(syntax);
         return this;
     }
+
+    public int getIsolationLevel() {
+        return _fetch.getIsolationLevel();
+    }
+
+    public JDBCFetchPlan setIsolationLevel(int level) {
+        _fetch.setIsolationLevel(level);
+        return this;
+    }
 }

openjpa-persistence-jdbc/src/test/java/org/apache/openjpa/persistence/jdbc/TestIsolationLevelOverride.java

@@ -0,0 +1,70 @@
+/*
+ * Copyright 2006 The Apache Software Foundation.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.openjpa.persistence.jdbc;
+
+import java.sql.Connection;
+import javax.persistence.EntityManager;
+import javax.persistence.LockModeType;
+import javax.persistence.PersistenceException;
+
+import org.apache.openjpa.persistence.test.SQLListenerTestCase;
+import org.apache.openjpa.persistence.simple.AllFieldTypes;
+import org.apache.openjpa.persistence.OpenJPAPersistence;
+import org.apache.openjpa.persistence.FetchPlan;
+import org.apache.openjpa.persistence.OpenJPAEntityManager;
+import org.apache.openjpa.jdbc.sql.DBDictionary;
+import org.apache.openjpa.jdbc.sql.DB2Dictionary;
+import org.apache.openjpa.jdbc.conf.JDBCConfiguration;
+
+public class TestIsolationLevelOverride
+    extends SQLListenerTestCase {
+
+    public void setUp() {
+        setUp(AllFieldTypes.class,
+            "openjpa.Optimistic", "false",
+            "openjpa.LockManager", "pessimistic");
+    }
+
+    public void testIsolationLevelOverride() {
+        OpenJPAEntityManager em =
+            OpenJPAPersistence.cast(emf.createEntityManager());
+        DBDictionary dict = ((JDBCConfiguration) em.getConfiguration())
+            .getDBDictionaryInstance();
+        sql.clear();
+        try {
+            em.getTransaction().begin();
+            ((JDBCFetchPlan) em.getFetchPlan())
+                .setIsolationLevel(Connection.TRANSACTION_SERIALIZABLE);
+            em.find(AllFieldTypes.class, 0);
+
+            if (dict instanceof DB2Dictionary) {
+                assertEquals(1, sql.size());
+                assertSQL(".*DB2-specific SQL to test for goes here.*");
+            } else {
+                fail("OpenJPA currently only supports per-query isolation " +
+                    "level configuration on the following databases: DB2");
+            }
+        } catch (PersistenceException pe) {
+            // if we're not using DB2, we expect an IllegalStateException.
+            if (dict instanceof DB2Dictionary
+                || !(pe.getCause() instanceof IllegalStateException))
+                throw pe;
+        } finally {
+            em.getTransaction().rollback();
+            em.close();
+        }
+    }
+}

openjpa-persistence-jdbc/src/test/java/org/apache/openjpa/persistence/jdbc/TestSelectForUpdateOverride.java

@@ -0,0 +1,52 @@
+/*
+ * Copyright 2006 The Apache Software Foundation.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.openjpa.persistence.jdbc;
+
+import javax.persistence.EntityManager;
+import javax.persistence.LockModeType;
+
+import org.apache.openjpa.persistence.test.SQLListenerTestCase;
+import org.apache.openjpa.persistence.simple.AllFieldTypes;
+import org.apache.openjpa.persistence.OpenJPAPersistence;
+import org.apache.openjpa.persistence.FetchPlan;
+
+public class TestSelectForUpdateOverride
+    extends SQLListenerTestCase {
+
+    public void setUp() {
+        setUp(AllFieldTypes.class,
+            "openjpa.Optimistic", "false",
+            "openjpa.LockManager", "pessimistic",
+            "openjpa.ReadLockLevel", "none");
+    }
+
+    public void testSelectForUpdateOverride() {
+        EntityManager em = emf.createEntityManager();
+        sql.clear();
+        try {
+            em.getTransaction().begin();
+            OpenJPAPersistence.cast(em).getFetchPlan()
+                .setReadLockMode(LockModeType.WRITE);
+            em.find(AllFieldTypes.class, 0);
+
+            assertEquals(1, sql.size());
+            assertSQL(".*FOR UPDATE.*");
+        } finally {
+            em.getTransaction().rollback();
+            em.close();
+        }
+    }
+}