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Commons DBCP example source code file (PoolableCallableStatement.java)

This example Commons DBCP source code file (PoolableCallableStatement.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 - Commons DBCP tags/keywords

callablestatement, cannot, connection, delegatingcallablestatement, jdbc, keyedobjectpool, keyedobjectpool, list, object, object, poolablecallablestatement, poolablecallablestatement, sql, sqlexception, sqlexception, sqlnestedexception, util

The Commons DBCP PoolableCallableStatement.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.commons.dbcp;

import java.sql.CallableStatement;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;

import org.apache.commons.pool.KeyedObjectPool;

/**
 * A {@link DelegatingCallableStatement} that cooperates with
 * {@link PoolingConnection} to implement a pool of {@link CallableStatement}s.
 * <p>
 * The {@link #close} method returns this statement to its containing pool. (See {@link PoolingConnection}.)
 *
 * @see PoolingConnection
 * @version $Revision: 883040 $ $Date: 2009-11-22 01:01:20 -0500 (Sun, 22 Nov 2009) $
 * @since 1.3
 */
public class PoolableCallableStatement extends DelegatingCallableStatement implements CallableStatement {

    /**
     * The {@link KeyedObjectPool} from which this CallableStatement was obtained.
     */
    private final KeyedObjectPool _pool;

    /**
     * Key for this statement in the containing {@link KeyedObjectPool}.
     */
    private final Object _key;

    /**
     * Constructor.
     * 
     * @param stmt the underlying {@link CallableStatement}
     * @param key the key for this statement in the {@link KeyedObjectPool}
     * @param pool the {@link KeyedObjectPool} from which this CallableStatement was obtained
     * @param conn the {@link Connection} that created this CallableStatement
     */
    public PoolableCallableStatement(CallableStatement stmt, Object key, KeyedObjectPool pool, Connection conn) {
        super((DelegatingConnection)conn, stmt);
        _pool = pool;
        _key = key;

        // Remove from trace now because this statement will be 
        // added by the activate method.
        if(_conn != null) {
            _conn.removeTrace(this);
        }
    }

    /**
     * Returns the CallableStatement to the pool.  If {{@link #isClosed()}, this is a No-op.
     */
    public void close() throws SQLException {
        // calling close twice should have no effect
        if (!isClosed()) {
            try {
                _pool.returnObject(_key,this);
            } catch(SQLException e) {
                throw e;
            } catch(RuntimeException e) {
                throw e;
            } catch(Exception e) {
                throw new SQLNestedException("Cannot close CallableStatement (return to pool failed)", e);
            }
        }
    }

    /**
     * Activates after retrieval from the pool. Adds a trace for this CallableStatement to the Connection
     * that created it.
     */
    protected void activate() throws SQLException {
        _closed = false;
        if( _conn != null ) {
            _conn.addTrace( this );
        }
        super.activate();
    }

    /**
     * Passivates to prepare for return to the pool.  Removes the trace associated with this CallableStatement
     * from the Connection that created it.  Also closes any associated ResultSets.
     */
    protected void passivate() throws SQLException {
        _closed = true;
        if( _conn != null ) {
            _conn.removeTrace(this);
        }

        // The JDBC spec requires that a statment close any open
        // ResultSet's when it is closed.
        // FIXME The PreparedStatement we're wrapping should handle this for us.
        // See DBCP-10 for what could happen when ResultSets are closed twice.
        List resultSets = getTrace();
        if(resultSets != null) {
            ResultSet[] set = (ResultSet[])resultSets.toArray(new ResultSet[resultSets.size()]);
            for(int i = 0; i < set.length; i++) {
                set[i].close();
            }
            clearTrace();
        }

        super.passivate();
    }

}

Other Commons DBCP examples (source code examples)

Here is a short list of links related to this Commons DBCP PoolableCallableStatement.java source code file:

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