[摘要](fparam == null))throw new SQLException("ConnectionParam和FactoryParam不能为空");if (m_instanc...
(fparam == null))
throw new SQLException("ConnectionParam和FactoryParam不能为空");
if (m_instance == null)
{
synchronized(ConnectionFactory.class){
if (m_instance == null)
{
//new instance
//参数定制
m_instance = new ConnectionFactory();
m_instance.connparam = param;
m_instance.MaxConnectionCount = fparam.getMaxConn();
m_instance.MinConnectionCount = fparam.getMinConn();
m_instance.ManageType = fparam.getType();
m_instance.isflag = true;
//初始化，创建MinConnectionCount个连接
System.out.println("connection factory 创建！");
try{
for (int i=0; i < m_instance.MinConnectionCount; i++)
{
_Connection _conn = _Connection.getConnection(m_instance, m_instance.connparam);
if (_conn == null) continue;
System.out.println("connection创建");
m_instance.FreeConnectionPool.add(_conn);//加入空闲连接池
m_instance.current_conn_count ++;
//标志是否支持事务
m_instance.supportTransaction = _conn.isSupportTransaction();
}
}
catch(Exception e)
{
e.printStackTrace();
}
//根据策略判断是否需要查询
if (m_instance.ManageType != 0)
{
Thread t = new Thread(new FactoryMangeThread(m_instance));
t.start();
}
}
}
}
}
连接池的管理
对于连接池的管理，我是设想使用静态管理和动态管理两种策略，设置了最大限制，和恒定的连接数。使用了2个池，一个空闲池，一个使用池。静态就是使用的时候发现空闲连接不够再去检查。动态就是使用了一个线程定时检查。
//根据策略判断是否需要查询
if (m_instance.ManageType != 0)
{
Thread t = new Thread(new FactoryMangeThread(m_instance));
t.start();
}
//连接池调度线程
public class FactoryMangeThread implements Runnable {
ConnectionFactory cf = null;
long delay = 1000;
public FactoryMangeThread(ConnectionFactory obj)
{
cf = obj;
}
/* (non-Javadoc)
* @see java.lang.Runnable#run()
*/
public void run() {
while(true){
try{
Thread.sleep(delay);
}
catch(InterruptedException e){}
System.out.println("eeeee");
//判断是否已经关闭了工厂，那就退出监听
if (cf.isCreate())
cf.schedule();
else
System.exit(1);
}
}
}
最后给出完整的源代码：
_Connectio.java
package scut.ailab.connectionpool;
import java.lang.reflect.*;
import java.sql.*;
/**
* @author youyongming
* 定义数据库连接的代理类
*/
public class _Connection implements InvocationHandler {
//定义连接
private Connection conn = null;
//定义监控连接创建的语句
private Statement statRef = null;
private PreparedStatement prestatRef = null;
//是否支持事务标志
private boolean supportTransaction = false;
//数据库的忙状态
private boolean isFree = false;
//最后一次访问时间
long lastAccessTime = 0;
//定义要接管的函数的名字
String CREATESTATE = "createStatement";
String CLOSE = "close";
String PREPARESTATEMENT = "prepareStatement";
String COMMIT = "commit";
String ROLLBACK = "rollback";
/**
* 构造函数，采用私有，防止被直接创建
* @param param 连接参数
*/
private _Connection(ConnectionParam param) {
//记录日至
try{
//创建连接
Class.forName(param.getDriver()).newInstance();
conn = DriverManager.getConnection(param.getUrl(),param.getUser(), param.getPassword());
DatabaseMetaData dm = null;
dm = conn.getMetaData();
//判断是否支持事务
supportTransaction = dm.supportsTransactions();
}
catch(Exception e)
{
e.printStackTrace();
}
}
/* (non-Javadoc)
* @see java.lang.reflect.InvocationHandler#invoke
*(java.lang.Object, java.lang.reflect.Method, java.lang.Object[])
*/
public Object invoke(Object proxy, Method method, Object[] args)
throws Throwable {
Object obj = null;
//判断是否调用了close的方法，如果调用close方法则把连接置为无用状态
if(CLOSE.equals(method.getName()))
{
//设置不使用标志
setIsFree(false);
//检查是否有后续工作，清除该连接无用资源
if (statRef != null)
statRef.close();
if (prestatRef != null)
prestatRef.close();
return null;
}
//判断是使用了createStatement语句
if (CREATESTATE.equals(method.getName()))
{
obj = method.invoke(conn, args);
statRef = (Statement)obj;//记录语句
return obj;
}
//判断是使用了prepareStatement语句
if (PREPARESTATEMENT.equals(method.getName()))
{
obj = method.invoke(conn, args);
prestatRef = (PreparedStatement)obj;
return obj;
}
//如果不支持事务，就不执行该事物的代码
if ((COMMIT.equals(method.getName())
关键词：数据库连接池Java完成小结