dbpool.java

一个完整的代码管理系统的源代码

/*
 * Copyright (c) 2008-2010 Tanming1003 Inc.
 * All rights reserved.
 * 
 * tanming1003<[e-mail]>
 * 
 * 
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions 
 * are met:
 * 
 * Redistributions of source code must retain the above copyright 
 * notice, this list of conditions and the following disclaimer. 
 * Redistributions in binary form must reproduce the above copyright 
 * notice, this list of conditions and the following disclaimer in the 
 * documentation and/or other materials provided with the distribution. 
 * Neither the name of tanming1003 nor the names of its contributors 
 * may be used to endorse or promote products derived from this 
 * software without specific prior written permission. 
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 
 * REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
 * POSSIBILITY OF SUCH DAMAGE.
 */
package hunnu.edu.cn.product.common.db.pool;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Properties;
import java.util.Stack;

import hunnu.edu.cn.product.common.db.DBUtil;
import hunnu.edu.cn.product.log.LogLog;

/**
 * @author tanming1003
 * @date 2008-10-10
 * @time 下午01:54:30
 * @project_name Product
 * @package_name hunnu.edu.cn.product.common.db.pool
 * @file_name    DBPool.java
 * @version      1.0
 */
public class DBPool extends Pool
{
	private Properties properties;
	private Stack<Connection> dbpool;
	private static DBPool pool;
	private String userName;
	private String url;
	private String password;
	private String driver;
	private LogLog log=hunnu.edu.cn.product.log.LogFactory.newInstance().getLog(this.getClass());
	private int connections;
	
	private DBPool()
	{
		dbpool=new Stack<Connection>();
		currentSize=0;
		connections=0;
		properties=DBUtil.getResourceProperties();
	}
    
	protected static DBPool newInstance()
	{
		if(pool==null)
		   pool=new DBPool();
		return pool;
	}
	
	public void destroy()
	{
	    log.info("开始清空数据库连接池......");
	    log.info("数据库连接池的大小为："+dbpool.size());
	    for(int i=0;i<dbpool.size();i++)
	    {
	    	Connection connection=dbpool.get(i);
	    	try
			{
				connection.close();
				connection=null;
			}
			catch (SQLException e)
			{
				log.debug(e.getMessage(), e);
			}
	    }
	    dbpool.clear();
	    dbpool=null;
	    log.info("完成清空数据库连接池.....");
	}

	public synchronized void fill(Object object)
	{
	    if(this.connections<this.maxSize)
	    {
	    	dbpool.push((Connection)object);
	    	updateSize(dbpool);
	    	this.connections++;
	    	log.info("数据库连接池现在的大小是："+connections);
	    	this.notifyAll();
	    }
	    else
	    {
	    	System.out.println("数据库连接池已满.......");
	    	Connection conn=(Connection)object;
	    	try
			{
				log.info("开始关闭数据库连接.........");
	    		conn.close();
	    		log.info("完成关闭数据库连接.........");
			}
			catch (SQLException e)
			{
				log.debug(e.getMessage(), e);
			}
	    }
	}

	public synchronized Object get()
	{
		if(dbpool!=null&&!dbpool.empty())
		{
			this.connections--;
			return dbpool.pop();
		}
		else
		{
			if(this.connections<=this.maxSize)
			{
				for(int i=0;i<this.minSize;i++)
				   newConnection();
				return get();
			}
			else
			{
				System.out.println("数据库连接池已空，请稍等.........");
				try
				{
					this.wait(this.maxWait);
					return get();
				}
				catch (InterruptedException e)
				{
					e.printStackTrace();
				}
			}
		}
		return null;
	}
	
	public void init()
	{
	    log.info("开始初始化数据库连接池.......");
		
		String maxsize=properties.getProperty("maxSize");
	    String minsize=properties.getProperty("minSize");
	    String maxwait=properties.getProperty("maxWait");
	    
	    userName=properties.getProperty("userName");
	    password=properties.getProperty("password");
	    url=properties.getProperty("url");
	    driver=properties.getProperty("driver");
	    
	    this.setFull(false);
	    this.setMaxSize(Integer.valueOf(maxsize));
	    this.setMinSize(Integer.valueOf(minsize));
	    this.setMaxWait(Integer.valueOf(maxwait));
	    
	    try
		{
			Class.forName(driver);
			for(int i=0;i<minSize;i++)
		    {
		    	Connection connection=DriverManager.getConnection(url,userName, password);
		        if(connection!=null)
		        {
		        	dbpool.add(connection);
		        	this.connections++;
		        }
		    }
			this.setCurrentSize(dbpool.size());
			log.info("数据库连接池的大小为:"+dbpool.size());
		
		}
		catch (ClassNotFoundException e)
		{
			log.debug("The driver Class can't be found!", e);
		}
		catch (SQLException e)
		{
			log.debug("SQLException:", e);
		}
		
		log.info("成功初始化数据库连接池....... ");
	
	}

	/**
	 * @return the properties
	 */
	public Properties getProperties()
	{
		return properties;
	}

	/**
	 * @param properties the properties to set
	 */
	public void setProperties(Properties properties)
	{
		this.properties = properties;
	}

	/**
	 * @return the dbpool
	 */
	public Stack<Connection> getDbpool()
	{
		return dbpool;
	}

	/**
	 * @param dbpool the dbpool to set
	 */
	public void setDbpool(Stack<Connection> dbpool)
	{
		this.dbpool = dbpool;
	}

	/**
	 * @return the userName
	 */
	public String getUserName()
	{
		return userName;
	}

	/**
	 * @param userName the userName to set
	 */
	public void setUserName(String userName)
	{
		this.userName = userName;
	}

	/**
	 * @return the url
	 */
	public String getUrl()
	{
		return url;
	}

	/**
	 * @param url the url to set
	 */
	public void setUrl(String url)
	{
		this.url = url;
	}

	/**
	 * @return the password
	 */
	public String getPassword()
	{
		return password;
	}

	/**
	 * @param password the password to set
	 */
	public void setPassword(String password)
	{
		this.password = password;
	}

	/**
	 * @return the driver
	 */
	public String getDriver()
	{
		return driver;
	}

	/**
	 * @param driver the driver to set
	 */
	public void setDriver(String driver)
	{
		this.driver = driver;
	}
    
	public void updateSize(Stack<Connection> dbpool)
	{
		if(dbpool!=null)
		   this.currentSize=dbpool.size();
		else
		   this.currentSize=0;
	}

	/**
	 * @return the connections
	 */
	public int getConnections()
	{
		return connections;
	}

	/**
	 * @param connections the connections to set
	 */
	public void setConnections(int connections)
	{
		this.connections = connections;
	}
	
	public void newConnection()
	{
		if(this.connections<=this.maxSize)
		{
			try
			{
				Class.forName(this.driver);
				Connection connection=DriverManager.getConnection(url,userName,password);
				dbpool.add(connection);
				updateSize(dbpool);
				this.connections++;
			}
			catch (ClassNotFoundException e)
			{
				log.debug("Class can't be found!", e);
			}
			catch (SQLException e)
			{
				log.debug("SQLException:", e);
			}
		}
	}
}