Commons DBCP example source code file (TestAbandonedObjectPool.java)

This example Commons DBCP source code file (TestAbandonedObjectPool.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

abandonedconfig, abandonedobjectpool, concurrent_borrows, concurrent_borrows, concurrentborrower, concurrentborrower, exception, exception, pooledtestobject, pooledtestobject, simplefactory, testabandonedobjectpool, thread, util, vector

The Commons DBCP TestAbandonedObjectPool.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.util.Vector;

import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;

import org.apache.commons.pool.PoolableObjectFactory;

/**
 * TestCase for AbandonedObjectPool
 * 
 * @author Wayne Woodfield
 * @version $Revision: 479137 $ $Date: 2006-11-25 10:51:48 -0500 (Sat, 25 Nov 2006) $
 */
public class TestAbandonedObjectPool extends TestCase {
    private AbandonedObjectPool pool = null;
    private AbandonedConfig config = null;
    
    public TestAbandonedObjectPool(String testName) {
        super(testName);
    }

    public static Test suite() {
        return new TestSuite(TestAbandonedObjectPool.class);
    }

    public void setUp() throws Exception {
        super.setUp();
        config = new AbandonedConfig();
        
        // -- Uncomment the following line to enable logging -- 
        // config.setLogAbandoned(true);
        
        config.setRemoveAbandoned(true);
        config.setRemoveAbandonedTimeout(1);
        pool = new AbandonedObjectPool(new SimpleFactory(), config);
    }

    public void tearDown() throws Exception {
        super.tearDown();
        pool.close();
        pool = null;
    }

    /**
    * Tests fix for Bug 28579, a bug in AbandonedObjectPool that causes numActive to go negative
    * in GenericObjectPool
    */
    public void testConcurrentInvalidation() throws Exception {
        final int POOL_SIZE = 30;
        pool.setMaxActive(POOL_SIZE);
        pool.setMaxIdle(POOL_SIZE);
        pool.setWhenExhaustedAction(AbandonedObjectPool.WHEN_EXHAUSTED_FAIL);

        // Exhaust the connection pool
        Vector vec = new Vector();
        for (int i = 0; i < POOL_SIZE; i++) {
            vec.add(pool.borrowObject());
        }
        
        // Abandon all borrowed objects
        for (int i = 0; i < vec.size(); i++) {
            ((PooledTestObject)vec.elementAt(i)).setAbandoned(true);
        }

        // Try launching a bunch of borrows concurrently.  Abandoned sweep will be triggered for each.
        final int CONCURRENT_BORROWS = 5;
        Thread[] threads = new Thread[CONCURRENT_BORROWS];
        for (int i = 0; i < CONCURRENT_BORROWS; i++) {
            threads[i] = new ConcurrentBorrower(vec);
            threads[i].start();
        }

        // Wait for all the threads to finish
        for (int i = 0; i < CONCURRENT_BORROWS; i++) {
            threads[i].join();
        }
        
        // Return all objects that have not been destroyed
        for (int i = 0; i < vec.size(); i++) {
            PooledTestObject pto = (PooledTestObject)vec.elementAt(i);
            if (pto.isActive()) {
                pool.returnObject(pto);
            }
        }
        
        // Now, the number of open connections should be 0
        assertTrue("numActive should have been 0, was " + pool.getNumActive(), pool.getNumActive() == 0);
    }
    
    class ConcurrentBorrower extends Thread {
        private Vector _borrowed;
        
        public ConcurrentBorrower(Vector borrowed) {
            _borrowed = borrowed;
        }
        
        public void run() {
            try {
                _borrowed.add(pool.borrowObject());
            } catch (Exception e) {
                // expected in most cases
            }
        }
    }
    
    class SimpleFactory implements PoolableObjectFactory {

        public Object makeObject() {
            return new PooledTestObject(config);
        }
        
        public boolean validateObject(Object obj) { return true; }
        
        public void activateObject(Object obj) {
            ((PooledTestObject)obj).setActive(true);
        }
        
        public void passivateObject(Object obj) {
            ((PooledTestObject)obj).setActive(false);
        }

        public void destroyObject(Object obj) {
            ((PooledTestObject)obj).setActive(false);
            // while destroying connections, yield control to other threads
            // helps simulate threading errors
            Thread.yield();
        }
    }
}

class PooledTestObject extends AbandonedTrace {
    private boolean active = false;
    private int _hash = 0;
    private boolean _abandoned = false;

    private static int hash = 1;
    
    public PooledTestObject(AbandonedConfig config) {
        super(config);
        _hash = hash++;
    }
    
    public synchronized void setActive(boolean b) {
        active = b;
    }

    public synchronized boolean isActive() {
        return active;
    }
    
    public int hashCode() {
        return _hash;
    }
    
    public void setAbandoned(boolean b) {
        _abandoned = b;
    }
    
    protected long getLastUsed() {
        if (_abandoned) {
            // Abandoned object sweep will occur no matter what the value of removeAbandonedTimeout,
            // because this indicates that this object was last used decades ago
            return 1;
        } else {
            // Abandoned object sweep won't clean up this object
            return 0;
        }
    }
    
    public boolean equals(Object obj) {
        if (!(obj instanceof PooledTestObject)) return false;
        return obj.hashCode() == hashCode();
    }
}