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Commons DBCP example source code file (PerUserPoolDataSource.java)

This example Commons DBCP source code file (PerUserPoolDataSource.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

boolean, boolean, cpdsconnectionfactory, hashmap, integer, integer, io, jdbc, map, naming, namingexception, pooledconnectionmanager, poolkey, sql, sqlexception, sqlexception, string, string, util

The Commons DBCP PerUserPoolDataSource.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.datasources;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.NoSuchElementException;

import javax.naming.NamingException;
import javax.naming.Reference;
import javax.naming.StringRefAddr;
import javax.sql.ConnectionPoolDataSource;

import org.apache.commons.dbcp.SQLNestedException;

import org.apache.commons.pool.ObjectPool;
import org.apache.commons.pool.impl.GenericObjectPool;

/**
 * <p>A pooling DataSource appropriate for deployment within
 * J2EE environment.  There are many configuration options, most of which are
 * defined in the parent class.  This datasource uses individual pools per 
 * user, and some properties can be set specifically for a given user, if the 
 * deployment environment can support initialization of mapped properties.
 * So for example, a pool of admin or write-access Connections can be
 * guaranteed a certain number of connections, separate from a maximum
 * set for users with read-only connections.</p>
 * 
 * <p>User passwords can be changed without re-initializing the datasource.
 * When a <code>getConnection(username, password) request is processed 
 * with a password that is different from those used to create connections in the
 * pool associated with <code>username, an attempt is made to create a
 * new connection using the supplied password and if this succeeds, the existing
 * pool is cleared and a new pool is created for connections using the new password.</p>
 * 
 *
 * @author John D. McNally
 * @version $Revision: 907288 $ $Date: 2010-02-06 14:42:58 -0500 (Sat, 06 Feb 2010) $
 */
public class PerUserPoolDataSource
    extends InstanceKeyDataSource {

    private static final long serialVersionUID = -3104731034410444060L;

    private int defaultMaxActive = GenericObjectPool.DEFAULT_MAX_ACTIVE;
    private int defaultMaxIdle = GenericObjectPool.DEFAULT_MAX_IDLE;
    private int defaultMaxWait = (int)Math.min(Integer.MAX_VALUE,
        GenericObjectPool.DEFAULT_MAX_WAIT);
    Map perUserDefaultAutoCommit = null;    
    Map perUserDefaultTransactionIsolation = null;
    Map perUserMaxActive = null;    
    Map perUserMaxIdle = null;    
    Map perUserMaxWait = null;
    Map perUserDefaultReadOnly = null;    

    /**
     * Map to keep track of Pools for a given user
     */
    private transient Map /* <PoolKey, PooledConnectionManager> */ managers = new HashMap();

    /**
     * Default no-arg constructor for Serialization
     */
    public PerUserPoolDataSource() {
    }

    /**
     * Close pool(s) being maintained by this datasource.
     */
    public void close() {
        for (Iterator poolIter = managers.values().iterator();
             poolIter.hasNext();) {    
            try {
              ((CPDSConnectionFactory) poolIter.next()).getPool().close();
            } catch (Exception closePoolException) {
                    //ignore and try to close others.
            }
        }
        InstanceKeyObjectFactory.removeInstance(instanceKey);
    }

    // -------------------------------------------------------------------
    // Properties

    /**
     * The maximum number of active connections that can be allocated from
     * this pool at the same time, or non-positive for no limit.
     * This value is used for any username which is not specified
     * in perUserMaxConnections.
     */
    public int getDefaultMaxActive() {
        return (this.defaultMaxActive);
    }

    /**
     * The maximum number of active connections that can be allocated from
     * this pool at the same time, or non-positive for no limit.
     * This value is used for any username which is not specified
     * in perUserMaxConnections.  The default is 8.
     */
    public void setDefaultMaxActive(int maxActive) {
        assertInitializationAllowed();
        this.defaultMaxActive = maxActive;
    }

    /**
     * The maximum number of active connections that can remain idle in the
     * pool, without extra ones being released, or negative for no limit.
     * This value is used for any username which is not specified
     * in perUserMaxIdle.
     */
    public int getDefaultMaxIdle() {
        return (this.defaultMaxIdle);
    }

    /**
     * The maximum number of active connections that can remain idle in the
     * pool, without extra ones being released, or negative for no limit.
     * This value is used for any username which is not specified
     * in perUserMaxIdle.  The default is 8.
     */
    public void setDefaultMaxIdle(int defaultMaxIdle) {
        assertInitializationAllowed();
        this.defaultMaxIdle = defaultMaxIdle;
    }

    /**
     * The maximum number of milliseconds that the pool will wait (when there
     * are no available connections) for a connection to be returned before
     * throwing an exception, or -1 to wait indefinitely.  Will fail 
     * immediately if value is 0.
     * This value is used for any username which is not specified
     * in perUserMaxWait.  The default is -1.
     */
    public int getDefaultMaxWait() {
        return (this.defaultMaxWait);
    }

    /**
     * The maximum number of milliseconds that the pool will wait (when there
     * are no available connections) for a connection to be returned before
     * throwing an exception, or -1 to wait indefinitely.  Will fail 
     * immediately if value is 0.
     * This value is used for any username which is not specified
     * in perUserMaxWait.  The default is -1.
     */
    public void setDefaultMaxWait(int defaultMaxWait) {
        assertInitializationAllowed();
        this.defaultMaxWait = defaultMaxWait;
    }

    /**
     * The keys are usernames and the value is the --.  Any 
     * username specified here will override the value of defaultAutoCommit.
     */
    public Boolean getPerUserDefaultAutoCommit(String key) {
        Boolean value = null;
        if (perUserDefaultAutoCommit != null) {
            value = (Boolean) perUserDefaultAutoCommit.get(key);
        }
        return value;
    }
    
    /**
     * The keys are usernames and the value is the --.  Any 
     * username specified here will override the value of defaultAutoCommit.
     */
    public void setPerUserDefaultAutoCommit(String username, Boolean value) {
        assertInitializationAllowed();
        if (perUserDefaultAutoCommit == null) {
            perUserDefaultAutoCommit = new HashMap();
        }
        perUserDefaultAutoCommit.put(username, value);
    }

    /**
     * The isolation level of connections when returned from getConnection.  
     * If null, the username will use the value of defaultTransactionIsolation.
     */
    public Integer getPerUserDefaultTransactionIsolation(String username) {
        Integer value = null;
        if (perUserDefaultTransactionIsolation != null) {
            value = (Integer) perUserDefaultTransactionIsolation.get(username);
        }
        return value;
    }

    /**
     * The isolation level of connections when returned from getConnection.  
     * Valid values are the constants defined in Connection.
     */
    public void setPerUserDefaultTransactionIsolation(String username, 
                                                      Integer value) {
        assertInitializationAllowed();
        if (perUserDefaultTransactionIsolation == null) {
            perUserDefaultTransactionIsolation = new HashMap();
        }
        perUserDefaultTransactionIsolation.put(username, value);
    }

    /**
     * The maximum number of active connections that can be allocated from
     * this pool at the same time, or non-positive for no limit.
     * The keys are usernames and the value is the maximum connections.  Any 
     * username specified here will override the value of defaultMaxActive.
     */
    public Integer getPerUserMaxActive(String username) {
        Integer value = null;
        if (perUserMaxActive != null) {
            value = (Integer) perUserMaxActive.get(username);
        }
        return value;
    }
    
    /**
     * The maximum number of active connections that can be allocated from
     * this pool at the same time, or non-positive for no limit.
     * The keys are usernames and the value is the maximum connections.  Any 
     * username specified here will override the value of defaultMaxActive.
     */
    public void setPerUserMaxActive(String username, Integer value) {
        assertInitializationAllowed();
        if (perUserMaxActive == null) {
            perUserMaxActive = new HashMap();
        }
        perUserMaxActive.put(username, value);
    }


    /**
     * The maximum number of active connections that can remain idle in the
     * pool, without extra ones being released, or negative for no limit.
     * The keys are usernames and the value is the maximum connections.  Any 
     * username specified here will override the value of defaultMaxIdle.
     */
    public Integer getPerUserMaxIdle(String username) {
        Integer value = null;
        if (perUserMaxIdle != null) {
            value = (Integer) perUserMaxIdle.get(username);
        }
        return value;
    }
    
    /**
     * The maximum number of active connections that can remain idle in the
     * pool, without extra ones being released, or negative for no limit.
     * The keys are usernames and the value is the maximum connections.  Any 
     * username specified here will override the value of defaultMaxIdle.
     */
    public void setPerUserMaxIdle(String username, Integer value) {
        assertInitializationAllowed();
        if (perUserMaxIdle == null) {
            perUserMaxIdle = new HashMap();
        }
        perUserMaxIdle.put(username, value);
    }
    
    /**
     * The maximum number of milliseconds that the pool will wait (when there
     * are no available connections) for a connection to be returned before
     * throwing an exception, or -1 to wait indefinitely.  Will fail 
     * immediately if value is 0.
     * The keys are usernames and the value is the maximum connections.  Any 
     * username specified here will override the value of defaultMaxWait.
     */
    public Integer getPerUserMaxWait(String username) {
        Integer value = null;
        if (perUserMaxWait != null) {
            value = (Integer) perUserMaxWait.get(username);
        }
        return value;
    }
    
    /**
     * The maximum number of milliseconds that the pool will wait (when there
     * are no available connections) for a connection to be returned before
     * throwing an exception, or -1 to wait indefinitely.  Will fail 
     * immediately if value is 0.
     * The keys are usernames and the value is the maximum connections.  Any 
     * username specified here will override the value of defaultMaxWait.
     */
    public void setPerUserMaxWait(String username, Integer value) {
        assertInitializationAllowed();
        if (perUserMaxWait == null) {
            perUserMaxWait = new HashMap();
        }
        perUserMaxWait.put(username, value);
    }

    /**
     * The keys are usernames and the value is the --.  Any 
     * username specified here will override the value of defaultReadOnly.
     */
    public Boolean getPerUserDefaultReadOnly(String username) {
        Boolean value = null;
        if (perUserDefaultReadOnly != null) {
            value = (Boolean) perUserDefaultReadOnly.get(username);
        }
        return value;
    }
    
    /**
     * The keys are usernames and the value is the --.  Any 
     * username specified here will override the value of defaultReadOnly.
     */
    public void setPerUserDefaultReadOnly(String username, Boolean value) {
        assertInitializationAllowed();
        if (perUserDefaultReadOnly == null) {
            perUserDefaultReadOnly = new HashMap();
        }
        perUserDefaultReadOnly.put(username, value);
    }

    // ----------------------------------------------------------------------
    // Instrumentation Methods

    /**
     * Get the number of active connections in the default pool.
     */
    public int getNumActive() {
        return getNumActive(null, null);
    }

    /**
     * Get the number of active connections in the pool for a given user.
     */
    public int getNumActive(String username, String password) {
        ObjectPool pool = getPool(getPoolKey(username,password));
        return (pool == null) ? 0 : pool.getNumActive();
    }

    /**
     * Get the number of idle connections in the default pool.
     */
    public int getNumIdle() {
        return getNumIdle(null, null);
    }

    /**
     * Get the number of idle connections in the pool for a given user.
     */
    public int getNumIdle(String username, String password) {
        ObjectPool pool = getPool(getPoolKey(username,password));
        return (pool == null) ? 0 : pool.getNumIdle();
    }


    // ----------------------------------------------------------------------
    // Inherited abstract methods

    protected PooledConnectionAndInfo 
        getPooledConnectionAndInfo(String username, String password)
        throws SQLException {

        final PoolKey key = getPoolKey(username,password);
        ObjectPool pool;
        PooledConnectionManager manager;
        synchronized(this) {
            manager = (PooledConnectionManager) managers.get(key);
            if (manager == null) {
                try {
                    registerPool(username, password);
                    manager = (PooledConnectionManager) managers.get(key);
                } catch (NamingException e) {
                    throw new SQLNestedException("RegisterPool failed", e);
                }
            }
            pool = ((CPDSConnectionFactory) manager).getPool();
        }

        PooledConnectionAndInfo info = null;
        try {
            info = (PooledConnectionAndInfo) pool.borrowObject();
        }
        catch (NoSuchElementException ex) {
            throw new SQLNestedException(
                    "Could not retrieve connection info from pool", ex);
        }
        catch (Exception e) {
            // See if failure is due to CPDSConnectionFactory authentication failure
            try {
                testCPDS(username, password);
            } catch (Exception ex) {
                throw (SQLException) new SQLException(
                        "Could not retrieve connection info from pool").initCause(ex);
            }
            // New password works, so kill the old pool, create a new one, and borrow
            manager.closePool(username);
            synchronized (this) {
                managers.remove(key);
            }
            try {
                registerPool(username, password);
                pool = getPool(key);
            } catch (NamingException ne) {
                throw new SQLNestedException("RegisterPool failed", ne);
            }
            try {
                info = (PooledConnectionAndInfo)((ObjectPool) pool).borrowObject();
            } catch (Exception ex) {
                throw (SQLException) new SQLException(
                "Could not retrieve connection info from pool").initCause(ex);
            }
        }
        return info;
    }

    protected void setupDefaults(Connection con, String username) 
        throws SQLException {
        boolean defaultAutoCommit = isDefaultAutoCommit();
        if (username != null) {
            Boolean userMax = getPerUserDefaultAutoCommit(username);
            if (userMax != null) {
                defaultAutoCommit = userMax.booleanValue();
            }
        }    

        boolean defaultReadOnly = isDefaultReadOnly();
        if (username != null) {
            Boolean userMax = getPerUserDefaultReadOnly(username);
            if (userMax != null) {
                defaultReadOnly = userMax.booleanValue();
            }
        }    

        int defaultTransactionIsolation = getDefaultTransactionIsolation();
        if (username != null) {
            Integer userMax = getPerUserDefaultTransactionIsolation(username);
            if (userMax != null) {
                defaultTransactionIsolation = userMax.intValue();
            }
        }

        if (con.getAutoCommit() != defaultAutoCommit) {
            con.setAutoCommit(defaultAutoCommit);
        }

        if (defaultTransactionIsolation != UNKNOWN_TRANSACTIONISOLATION) {
            con.setTransactionIsolation(defaultTransactionIsolation);
        }

        if (con.isReadOnly() != defaultReadOnly) {
            con.setReadOnly(defaultReadOnly);
        }
    }
    
    protected PooledConnectionManager getConnectionManager(UserPassKey upkey) {
        return (PooledConnectionManager) managers.get(getPoolKey(
                upkey.getUsername(), upkey.getPassword()));
    }

    /**
     * Returns a <code>PerUserPoolDataSource {@link Reference}.
     * 
     * @since 1.2.2
     */
    public Reference getReference() throws NamingException {
        Reference ref = new Reference(getClass().getName(),
                PerUserPoolDataSourceFactory.class.getName(), null);
        ref.add(new StringRefAddr("instanceKey", instanceKey));
        return ref;
    }
    
    private PoolKey getPoolKey(String username, String password) { 
        return new PoolKey(getDataSourceName(), username); 
    }

    private synchronized void registerPool(
        String username, String password) 
        throws javax.naming.NamingException, SQLException {

        ConnectionPoolDataSource cpds = testCPDS(username, password);

        Integer userMax = getPerUserMaxActive(username);
        int maxActive = (userMax == null) ? 
            getDefaultMaxActive() : userMax.intValue();
        userMax = getPerUserMaxIdle(username);
        int maxIdle =  (userMax == null) ?
            getDefaultMaxIdle() : userMax.intValue();
        userMax = getPerUserMaxWait(username);
        int maxWait = (userMax == null) ?
            getDefaultMaxWait() : userMax.intValue();

        // Create an object pool to contain our PooledConnections
        GenericObjectPool pool = new GenericObjectPool(null);
        pool.setMaxActive(maxActive);
        pool.setMaxIdle(maxIdle);
        pool.setMaxWait(maxWait);
        pool.setWhenExhaustedAction(whenExhaustedAction(maxActive, maxWait));
        pool.setTestOnBorrow(getTestOnBorrow());
        pool.setTestOnReturn(getTestOnReturn());
        pool.setTimeBetweenEvictionRunsMillis(
            getTimeBetweenEvictionRunsMillis());
        pool.setNumTestsPerEvictionRun(getNumTestsPerEvictionRun());
        pool.setMinEvictableIdleTimeMillis(getMinEvictableIdleTimeMillis());
        pool.setTestWhileIdle(getTestWhileIdle());
                
        // Set up the factory we will use (passing the pool associates
        // the factory with the pool, so we do not have to do so
        // explicitly)
        CPDSConnectionFactory factory = new CPDSConnectionFactory(cpds, pool, getValidationQuery(),
                isRollbackAfterValidation(), username, password);
           
        Object old = managers.put(getPoolKey(username,password), factory);
        if (old != null) {
            throw new IllegalStateException("Pool already contains an entry for this user/password: "+username);
        }
    }

    /**
     * Supports Serialization interface.
     *
     * @param in a <code>java.io.ObjectInputStream value
     * @exception IOException if an error occurs
     * @exception ClassNotFoundException if an error occurs
     */
    private void readObject(ObjectInputStream in)
        throws IOException, ClassNotFoundException {
        try 
        {
            in.defaultReadObject();
            PerUserPoolDataSource oldDS = (PerUserPoolDataSource)
                new PerUserPoolDataSourceFactory()
                    .getObjectInstance(getReference(), null, null, null);
            this.managers = oldDS.managers;
        }
        catch (NamingException e)
        {
            throw new IOException("NamingException: " + e);
        }
    }
    
    /**
     * Returns the object pool associated with the given PoolKey.
     * 
     * @param key PoolKey identifying the pool 
     * @return the GenericObjectPool pooling connections for the username and datasource
     * specified by the PoolKey
     */
    private GenericObjectPool getPool(PoolKey key) {
        CPDSConnectionFactory mgr = (CPDSConnectionFactory) managers.get(key);
        return mgr == null ? null : (GenericObjectPool) mgr.getPool();
    }
}

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