connectionpoolmanager.java

JSP聊天系统

package org.ehotsoft.yekki.sql.pool;

import java.sql.*;
import java.util.*;

public class ConnectionPoolManager implements Driver, Runnable {

	public static final String URL_PREFIX = "jdbc:yekki:pool:";
	public static final int MAJOR_VERSION = 1;
	public static final int MINOR_VERSION = 0;

	private Hashtable aliasHash;
	private long sleepInterval;
	private boolean trace;

	public ConnectionPoolManager() throws SQLException {

		aliasHash = new Hashtable();
		DriverManager.registerDriver( this );
		trace = false;
	}

	public ConnectionPoolManager( int monitorInterval ) throws SQLException {

		this();
		this.sleepInterval = monitorInterval * 1000;
		
		Thread t = new Thread( this );
		t.setDaemon( true );
		t.start();
	}

	 public void addAlias( String alias, String driver, String url, String username,
				String password, int maxConn, int idleTimeout, int checkoutTimeout  ) 
		throws ClassNotFoundException, InstantiationException, IllegalAccessException {

		addAlias( alias, driver, url, username, password, maxConn, idleTimeout, checkoutTimeout, 0 );
	}

 
	public void addAlias( String alias, String driver, String url, String username, String password,
			   int maxConn, int idleTimeout, int checkoutTimeout, int maxCheckout )
		throws ClassNotFoundException, InstantiationException, IllegalAccessException {
		
		addAlias( alias, driver, url, username, password, maxConn, idleTimeout, checkoutTimeout, maxCheckout, true );
	}
  
	public void addAlias( String alias, String driver, String url, String username, String password,
			   int maxConn, int idleTimeout, int checkoutTimeout, int maxCheckout, boolean cacheStatements )
		throws ClassNotFoundException, InstantiationException, IllegalAccessException {
		
		Class.forName(driver).newInstance();
		ConnectionPool pool = new ConnectionPool( alias, url, username, password, 
						 maxConn, idleTimeout, checkoutTimeout, maxCheckout );
		pool.setCacheStatements( cacheStatements );
		addAlias( pool );
	}

	public void addAlias(String alias, String driver, String url, String username, String password,
			   int maxConn, int idleTimeout, int checkoutTimeout, int maxCheckout, int rowPrefetch)
		throws ClassNotFoundException, InstantiationException, IllegalAccessException {
	  
		addAlias(alias, driver, url, username, password, maxConn,
			idleTimeout, checkoutTimeout, maxCheckout, rowPrefetch, true);
	}

	public void addAlias( String alias, String driver, String url, String username, String password,
			int maxConn, int idleTimeout, int checkoutTimeout,
			int maxCheckout, int rowPrefetch,boolean cacheStatements )

		throws ClassNotFoundException, InstantiationException, IllegalAccessException {

		Class.forName( driver ).newInstance();
		ConnectionPool pool = new ConnectionPool( alias, url, username, password,
						 maxConn, idleTimeout, checkoutTimeout, maxCheckout );
		pool.setCacheStatements( cacheStatements );
		pool.setPrefetchSize( rowPrefetch );
		addAlias( pool );
	}
  
	public synchronized void addAlias( ConnectionPool pool ) {

		aliasHash.put(pool.getAlias(), pool);
	}


	public synchronized void removeAlias( String alias )
		throws SQLException {
		
		ConnectionPool p = getPool( alias );
		aliasHash.remove(alias);
		p.removeAllConnections();
	}

	public Enumeration getPools() {

		return aliasHash.elements();
	}

	public ConnectionPool getPool(String alias) throws SQLException {

		ConnectionPool p = ( ConnectionPool )aliasHash.get(alias);
		
		if( p == null ) {
			
			throw new SQLException( "No connection pool created for alias: " + alias );
		}

		return p;
	}

  	public void run() {

		while( true ) {

			try {

				Thread.currentThread().sleep( sleepInterval );
			}
			catch( InterruptedException e ) { }

			for ( Enumeration enum = aliasHash.elements(); enum.hasMoreElements(); ) {

				ConnectionPool pool = ( ConnectionPool )enum.nextElement();
				
				try {
					pool.reapIdleConnections();
				}
				catch( Exception e ) {

					e.printStackTrace();
				}
			}
		}
	}

	public void setTracing( boolean on ) {

		if ( on != trace ) {

			for ( Enumeration e = getPools(); e.hasMoreElements(); ) {

				ConnectionPool p = (ConnectionPool)e.nextElement();
				p.setTracing(on);
			}

			String str = "off";
			if( on ) str = "on";

			System.err.println( "ConnectionPoolManager: Tracing turned " + str );

			trace = on;
		}
	}

	public String dumpInfo() {

		String LS = System.getProperty( "line.separator" );
		Enumeration allPools = getPools();
		ConnectionPool currentPool = null;
		StringBuffer report = new StringBuffer();

		while (allPools.hasMoreElements()) {

		  currentPool = ( ConnectionPool )allPools.nextElement();
		  report.append( currentPool.dumpInfo() );
		}

		return report.toString();
	}

	//implements Driver infterface
	public Connection connect( String url, Properties props ) throws SQLException {
	
		if ( !url.startsWith( URL_PREFIX ) ) {
			
			return null;
		}

		if ( url.length() <= URL_PREFIX.length() ) {

			throw new SQLException("Invalid URL: " + url + " -- No alias given");
		}

		String alias = url.substring( URL_PREFIX.length() );

		if ( trace ) System.err.println("ConnectionPoolManager: connect() called for " + alias + ".  calling pool.getConnection()");

		ConnectionPool p = getPool( alias );

		return p.getConnection();
	}

  	public boolean acceptsURL( String url ) {

		return url.startsWith( URL_PREFIX );
	}

	public DriverPropertyInfo[] getPropertyInfo( String str, Properties props ) {

		return new DriverPropertyInfo[ 0 ];
	}

 	public boolean jdbcCompliant() {

		return false;
	}

	public int getMajorVersion() {
		
		return MAJOR_VERSION;
	}

	public int getMinorVersion() {
		
		return MINOR_VERSION;
	}
}