java ee-数据源连接池DriverPool
DriverPool类，直接由数据库驱动程序构建，便于开发和调试单机高效的非事务程序
Public class DriverPool implements IConnPool{
private String driverName;
private String conURL;
private username;
private password;
private int min,max;
Vector conPool;
private Driver drv;
private class PooledConnection{
private Connection con;
privateboolean available;
private PooledConnection(Connection con,boolean available){
this.con=con;
this.available=available;
}
Connection getConnection(){
return con;
}
boolean isAvailable(){
return available;
}
void setAvailable(boolean available){
conAvailable=available;
}
}
//构造器
public DriverPool(int max,int min,String driverName,String conURL,String username,String password){
this.driverName=driverName;
this.conURL=conURL;
this.username=username;
this.password=password;
this.max=max;
this.min=min;
conPool=new Vector();
addConnectionsToPool(this.min);
//连接池后台监控启动
new PoolMonitor().startNow();
}
private synchronized void addConnectionsToPool(int numPooledCon){
try{
if(drv==null){
drv=(Driver) Class.forName(driverName).netIntance();
DriverManger.registerDriver(drv);
}
for(int i=0;i<numPooledCon;i++){
Connection con=DriverManger.getConnection(conURL,username,password);
PooledConnection pc=newPooledConnection(con,true);
conPool.add(pc);
}
}
catch(Exception e){
e.printStackTrace();
}
}
///监控连接池中的情况，实时回收无效的连接和根据要求往连接池中添加有效地连接，在监控线程中调用
private void moniPool{
removeAnyClosedConnections(); //删除所有无效的连接
if(this.conPool.size()<this.min){
int x=(this.max-this.min)/2;
int y=this.min-this.conPool.size();
if(x>0){
if(x+j>this.max){
this.addConnectionsToPool(x);
}
else{
this.addConnectionsToPool(x+j);
}
}
else(
this.addConnectionToPool(j);
}
}
}
}
private synchronized void removeAnyClosedConnection(){
try{
boolean done=false;
while(!done){
done=true;
for(int i=0;i<conPool.size();i+=){
PooledConnection pc=(PooledConnection) conPool.get(i);
if(pc.getConnection().isClosed()){
conPool.remove();
done=false;
break;
}
}
}
}
catch(SQLException e){
e.printStackTrace();
}
}
//从连接池中取出一个有效的连接
public synchronized Connection getConnection(){
//从池中找出一个有效的连接，返回
for(i=0;i<conPool.size();i++)
{
PooledConnection pc=(PooledConnection) conPool.get(i);
if(pc.isAvailable(){
pc.setAvailbale(false);
return pc.getConnection();
}
}
//如果池中没有就加一个，并返回，保证每个请求都有有效的连接返回
addConnectionsToPool(1);
PooledConnection pc=(PooledConnection) conPool.size()-1);
if(pc.isAvailable()){
pc.setAvailable(false);
}
return pc.getConnection();
}
//关闭连接池中的所有连接
public void closeAllConnections(){
for(int i=0;i<conPool.size();i++){
PooledConnection pc=(PooledConnecion) conPool.get(i);
closeConnection(pc.getConnection());
}
conPool.clear();
}
private void closeConnection(Connection con){
try{
if(con!=null){
con.close();
}
}
catch(SQLException e){
e.printStackTrace();
}
}
//后台监控线程，每秒监控一次
private class PoolMonitor
extends com.beetle.framework.appsrv.AppRunnable{
privat int time;
public PoolMonitor(){
super();
time=1000;
}
protected void end(){
closeAllConnections();
}
public void run(){
while(!this.getStopFlag()){
moniPool();
sleep(time);
}
}
}
}