ActiveMQ example source code file (TransactionContext.java)

This example ActiveMQ source code file (TransactionContext.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - ActiveMQ tags/keywords

already, commit, connection, failed, failed, io, ioexception, ioexception, jdbc, not, preparedstatement, preparedstatement, sql, sqlexception, sqlexception, throwable, transactioncontext

The ActiveMQ TransactionContext.java source code

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.activemq.store.jdbc;

import java.io.IOException;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.sql.Statement;

import javax.sql.DataSource;

import org.apache.activemq.util.IOExceptionSupport;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Helps keep track of the current transaction/JDBC connection.
 * 
 * 
 */
public class TransactionContext {

    private static final Logger LOG = LoggerFactory.getLogger(TransactionContext.class);

    private final DataSource dataSource;
    private final JDBCPersistenceAdapter persistenceAdapter;
    private Connection connection;
    private boolean inTx;
    private PreparedStatement addMessageStatement;
    private PreparedStatement removedMessageStatement;
    private PreparedStatement updateLastAckStatement;
    // a cheap dirty level that we can live with    
    private int transactionIsolation = Connection.TRANSACTION_READ_UNCOMMITTED;
    
    public TransactionContext(JDBCPersistenceAdapter persistenceAdapter) throws IOException {
        this.persistenceAdapter = persistenceAdapter;
        this.dataSource = persistenceAdapter.getDataSource();
    }

    public Connection getConnection() throws IOException {
        if (connection == null) {
            try {
                connection = dataSource.getConnection();
                boolean autoCommit = !inTx;
                if (connection.getAutoCommit() != autoCommit) {
                    connection.setAutoCommit(autoCommit);
                }
            } catch (SQLException e) {
                JDBCPersistenceAdapter.log("Could not get JDBC connection: ", e);
                IOException ioe = IOExceptionSupport.create(e);
                persistenceAdapter.getBrokerService().handleIOException(ioe);
                throw ioe;

            }

            try {
                connection.setTransactionIsolation(transactionIsolation);
            } catch (Throwable e) {
            }
        }
        return connection;
    }

    public void executeBatch() throws SQLException {
        try {
            executeBatch(addMessageStatement, "Failed add a message");
        } finally {
            addMessageStatement = null;
            try {
                executeBatch(removedMessageStatement, "Failed to remove a message");
            } finally {
                removedMessageStatement = null;
                try {
                    executeBatch(updateLastAckStatement, "Failed to ack a message");
                } finally {
                    updateLastAckStatement = null;
                }
            }
        }
    }

    private void executeBatch(PreparedStatement p, String message) throws SQLException {
        if (p == null) {
            return;
        }

        try {
            int[] rc = p.executeBatch();
            for (int i = 0; i < rc.length; i++) {
                int code = rc[i];
                if (code < 0 && code != Statement.SUCCESS_NO_INFO) {
                    throw new SQLException(message + ". Response code: " + code);
                }
            }
        } finally {
            try {
                p.close();
            } catch (Throwable e) {
            }
        }
    }

    public void close() throws IOException {
        if (!inTx) {
            try {

                /**
                 * we are not in a transaction so should not be committing ??
                 * This was previously commented out - but had adverse affects
                 * on testing - so it's back!
                 * 
                 */
                try {
                    executeBatch();
                } finally {
                    if (connection != null && !connection.getAutoCommit()) {
                        connection.commit();
                    }
                }

            } catch (SQLException e) {
                JDBCPersistenceAdapter.log("Error while closing connection: ", e);
                throw IOExceptionSupport.create(e);
            } finally {
                try {
                    if (connection != null) {
                        connection.close();
                    }
                } catch (Throwable e) {
                    LOG.warn("Close failed: " + e.getMessage(), e);
                } finally {
                    connection = null;
                }
            }
        }
    }

    public void begin() throws IOException {
        if (inTx) {
            throw new IOException("Already started.");
        }
        inTx = true;
        connection = getConnection();
    }

    public void commit() throws IOException {
        if (!inTx) {
            throw new IOException("Not started.");
        }
        try {
            executeBatch();
            if (!connection.getAutoCommit()) {
                connection.commit();
            }
        } catch (SQLException e) {
            JDBCPersistenceAdapter.log("Commit failed: ", e);
            
            this.rollback(); 
            
            throw IOExceptionSupport.create(e);
        } finally {
            inTx = false;
            close();
        }
    }

    public void rollback() throws IOException {
        if (!inTx) {
            throw new IOException("Not started.");
        }
        try {
            if (addMessageStatement != null) {
                addMessageStatement.close();
                addMessageStatement = null;
            }
            if (removedMessageStatement != null) {
                removedMessageStatement.close();
                removedMessageStatement = null;
            }
            if (updateLastAckStatement != null) {
                updateLastAckStatement.close();
                updateLastAckStatement = null;
            }
            connection.rollback();

        } catch (SQLException e) {
            JDBCPersistenceAdapter.log("Rollback failed: ", e);
            throw IOExceptionSupport.create(e);
        } finally {
            inTx = false;
            close();
        }
    }

    public PreparedStatement getAddMessageStatement() {
        return addMessageStatement;
    }

    public void setAddMessageStatement(PreparedStatement addMessageStatement) {
        this.addMessageStatement = addMessageStatement;
    }

    public PreparedStatement getUpdateLastAckStatement() {
        return updateLastAckStatement;
    }

    public void setUpdateLastAckStatement(PreparedStatement ackMessageStatement) {
        this.updateLastAckStatement = ackMessageStatement;
    }

    public PreparedStatement getRemovedMessageStatement() {
        return removedMessageStatement;
    }

    public void setRemovedMessageStatement(PreparedStatement removedMessageStatement) {
        this.removedMessageStatement = removedMessageStatement;
    }
    
    public void setTransactionIsolation(int transactionIsolation) {
        this.transactionIsolation = transactionIsolation;
    }

}