[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();
}
}
}
}
}
/**
* 标志工厂是否已经创建
* @return boolean
*/
public boolean isCreate()
{
return m_instance.isflag;
}
/**
* 从连接池中取一个空闲的连接
* @return Connection
* @throws SQLException
*/
public synchronized Connection getFreeConnection()
throws SQLException
{
Connection conn = null;
//获取空闲连接
Iterator iter = m_instance.FreeConnectionPool.iterator();
while(iter.hasNext()){
_Connection _conn = (_Connection)iter.next();
//找到未用连接
if(!_conn.isFree()){
conn = _conn.getFreeConnection();
_conn.setIsFree(true);
//移出空闲区
m_instance.FreeConnectionPool.remove(_conn);
//加入连接池
m_instance.ConnectionPool.add(_conn);
break;
}
}
//检查空闲池是否为空
if (m_instance.FreeConnectionPool.isEmpty())
{
//再检查是否能够分配
if (m_instance.current_conn_count < m_instance.MaxConnectionCount)
{
//新建连接到空闲连接池
int newcount = 0 ;
//取得要建立的数目
if (m_instance.MaxConnectionCount - m_instance.current_conn_count >=
m_instance.MinConnectionCount)
{
newcount = m_instance.MinConnectionCount;
}
else
{
newcount = m_instance.MaxConnectionCount - m_instance.current_conn_count;
}
//创建连接
for (int i=0;i <newcount; i++)
{
_Connection _conn = _Connection.getConnection(m_instance, m_instance.connparam);
m_instance.FreeConnectionPool.add(_conn);
m_instance.current_conn_count ++;
}
}
else
{//如果不能新建，检查是否有已经归还的连接
iter = m_instance.ConnectionPool.iterator();
while(iter.hasNext()){
_Connection _conn = (_Connection)iter.next();
if(!_conn.isFree()){
conn = _conn.getFreeConnection();
_conn.setIsFree(false);
m_instance.ConnectionPool.remove(_conn);
m_instance.FreeConnectionPool.add(_conn);
break;
}
}
}
}//if (FreeConnectionPool.isEmpty())
//再次检查是否能分配连接
if(conn == null){
iter = m_instance.FreeConnectionPool.iterator();
while(iter.hasNext()){
_Connection _conn = (_Connection)iter.next();
if(!_conn.isFree()){
conn = _conn.getFreeConnection();
_conn.setIsFree(true);
m_instance.FreeConnectionPool.remove(_conn);
m_instance.ConnectionPool.add(_conn);
break;
}
}
if(conn == null)//如果不能则说明无连接可用
throw new SQLException("没有可用的数据库连接");
}
System.out.println("get connection");
return conn;
}
/**
* 关闭该连接池中的所有数据库连接
* @throws SQLException
*/
public synchronized void close() throws SQLException
{
this.isflag = false;
SQLException excp = null;
//关闭空闲池
Iterator iter = m_instance.FreeConnectionPool.iterator();
while(iter.hasNext()){
try{
((_Connection)iter.next()).close();
System.out.println("close connection:free");
m_instance.current_conn_count --;
}catch(Exception e){
if(e instanceof SQLException)
excp = (SQLException)e;
}
}
//关闭在使用的连接池
iter = m_instance.ConnectionPool.iterator();
while(iter.hasNext()){
try{
((_Connection)iter.next()).close();
System.out.println("close connection:inused");
m_instance.current_conn_count --;
}catch(Exception e){
if(e instanceof SQLException)
excp = (SQLException)e;
}
}
if(excp != null)
throw excp;
}
/**
* 返回是否支持事务
* @return boolean
*/
public boolean isSupportTransaction() {
return m_instance.supportTransaction;
}
/**
* 连接池调度管理
*
*/
public void schedule()
{
Connection conn = null;
//再检查是否能够分配
Iterator iter = null;
//检查是否有已经归还的连接
{
iter = m_instance.ConnectionPool.iterator();
while(iter.hasNext()){
_Connection _conn = (_Connection)iter.next();
if(!_conn.isFree()){
conn = _conn.getFreeConnection();
_conn.setIsFree(false);
m_instance.ConnectionPool.remove(_conn);
m_instance.FreeConnectionPool.add(_conn);
break;
}
}
}
if (m_instance.current_conn_count < m_instance.MaxConnectionCount)
{
//新建连接到空闲连接池
int newcount = 0 ;
//取得要建立的数目
if (m_instance.MaxConnectionCount - m_instance.current_conn_count
>=m_instance.MinConnectionCount)
{
newcount = m_instance.MinConnectionCount;
}
else
{
newcount = m_instance.MaxConnectionCount - m_instance.current_conn_count;
}
//创建连接
for (int i=0;i <newcount; i++)
{
_Connection _conn = _Connection.getConnection(m_instance, m_instance.connparam);
m_instance.FreeConnectionPool.add(_conn);
m_instance.current_conn_count ++;
}
}
}
}
ConnectionParam.java
package scut.ailab.connectionpool;
import java.io.Serializable;
/**
* @author youyongming
* 实现数据库连接的参数类
*/
public class ConnectionParam implements Serializable {
private String driver; //数据库驱动程序
private String url; //数据连接的URL
private String user; //数据库用户名
private String password; //数据库密码
/**
* 唯一的构造函数，需要指定连接的四个必要参数
* @param driver 数据驱动
* @param url 数据库连接url
* @param user 用户名
* @param password 密码
*/
public ConnectionParam(String driver,String url,String user,String password)
{
this.driver = driver;
this.url = url;
this.user = user;
this.password = password;
}
public String getDriver() {
return driver;
}
public String getPassword() {
return password;
}
public String getUrl() {
return url;
}
public String getUser() {
return user;
}
public void setDriver(String driver) {
this.driver = driver;
}
public void setPassword(String password) {
this.password = password;
}
public void setUrl(String url) {
this.url = url;
}
public void setUser(String user) {
this.user = user;
}
/**
* @see java.lang.Object#clone()
*/
public Object clone(){
ConnectionParam param = new ConnectionParam(driver,url,user,password);
return param;
}
/**
* @see java.lang.Object#equals(java.lang.Object)
*/
public boolean equals(Object obj) {
if(obj instanceof ConnectionParam){
ConnectionParam param = (ConnectionParam)obj;
return ((driver.compareToIgnoreCase(param.getDriver()) == 0)&&
(url.compareToIgnoreCase(param.getUrl()) == 0)&&
(user.compareToIgnoreCase(param.getUser()) == 0)&&
(password.compareToIgnoreCase(param.getPassword()) == 0));
}
return false;
}
}
FactoryMangeThread.java
/*
* Created on 2003-5-13
*
* To change the template for this generated file go to
* Window>Preferences>Java>Code Generation>Code and Comments
*/
package scut.ailab.connectionpool;
/**
* @author youyongming
*
*/
//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);
}
}
}
FactoryParam.java
/*
* Created on 2003-5-13
*
* To change the template for this generated file go to
* Window>Preferences>Java>Code Generation>Code and Comments
*/
package scut.ailab.connectionpool;
/**
* @author youyongming
*
*/
//连接池工厂参数
public class FactoryParam {
//最大连接数
private int MaxConnectionCount = 4;
//最小连接数
private int MinConnectionCount = 2;
//回收策略
private int ManageType = 0;
public FactoryParam() {
}
/**
* 构造连接池工厂参数的对象
* @param max 最大连接数
* @param min 最小连接数
* @param type 管理策略
*/
public FactoryParam(int max, int min, int type)
{
this.ManageType = type;
this.MaxConnectionCount = max;
this.MinConnectionCount = min;
}
/**
* 设置最大的连接数
* @param value
*/
public void setMaxConn(int value)
{
this.MaxConnectionCount = value;
}
/**
* 获取最大连接数
* @return
*/
public int getMaxConn()
{
return this.MaxConnectionCount;
}
/**
* 设置最小连接数
* @param value
*/
public void setMinConn(int value)
{
this.MinConnectionCount = value;
}
/**
* 获取最小连接数
* @return
*/
public int getMinConn()
{
return this.MinConnectionCount;
}
public int getType()
{
return this.ManageType;
}
}
testmypool.java
/*
* Created on 2003-5-13
*
* To change the template for this generated file go to
* Window>Preferences>Java>Code Generation>Code and Comments
*/
package scut.ailab.connectionpool;
/**
* @author youyongming
*
*/
import java.sql.*;
public class testmypool {
public void test1()
{
String user = "DevTeam";
String password = "DevTeam";
String driver = "sun.jdbc.odbc.JdbcOdbcDriver";
String url = "jdbc:odbc:gfqh2";
ConnectionParam param = new ConnectionParam(driver,url,user,password);
ConnectionFactory cf = null;//new ConnectionFactory(param, new FactoryParam());
try{
cf = new ConnectionFactory(param,new FactoryParam());
Connection conn1 = cf.getFreeConnection();
Connection conn2 = cf.getFreeConnection();
Connection conn3 = cf.getFreeConnection();
Statement stmt = conn1.createStatement();
ResultSet rs = stmt.executeQuery("select * from requests");
if (rs.next())
{
System.out.println("conn1 y");
}
else
{
System.out.println("conn1 n");
}
stmt.close();
conn1.close();
Connection conn4 = cf.getFreeConnection();
Connection conn5 = cf.getFreeConnection();
stmt = conn5.createStatement();
rs = stmt.executeQuery("select * from requests");
if (rs.next())
{
System.out.println("conn5 y");
}
else
{
System.out.println("conn5 n");
}
conn2.close();
conn3.close();
conn4.close();
conn5.close();
}
catch(Exception e)
{
e.printStackTrace();
}
finally{
try{
cf.close();
}
catch(Exception e)
{
e.printStackTrace();
}
}
}
public static void main(String[] args) {
String user = "DevTeam";
String password = "DevTeam";
String driver = "sun.jdbc.odbc.JdbcOdbcDriver";
String url = "jdbc:odbc:gfqh2";
ConnectionParam param = new ConnectionParam(driver,url,user,password);
ConnectionFactory cf = null;//new ConnectionFactory(param,new FactoryParam());
try{
cf = new ConnectionFactory(param,new FactoryParam());
ConnectionFactory cf1= new ConnectionFactory(param,new FactoryParam());
Connection conn1 = null;
long time = System.currentTimeMillis();
for (int i=0; i <10;i++)
{
conn1 = cf.getFreeConnection();
Statement stmt = conn1.createStatement();
ResultSet rs = stmt.executeQuery("select * from requests");
if (rs.next())
{
System.out.println("conn1 y");
}
else
{
System.out.println("conn1 n");
}
conn1.close();
}
System.out.println("pool:" + (System.currentTimeMillis()-time));
time = System.currentTimeMillis();
Class.forName(param.getDriver()).newInstance();
for (int i=0; i <10;i++)
{
conn1 = DriverManager.getConnection(param.getUrl(),
param.getUser(), param.getPassword());
Statement stmt = conn1.createStatement();
ResultSet rs = stmt.executeQuery("select * from requests");
if (rs.next())
{
System.out.println("conn1 y");
}
else
{
System.out.println("conn1 n");
}
conn1.close();
}
System.out.println("no pool:" + (System.currentTimeMillis()-time));
}
catch(Exception e)
{
e.printStackTrace();
}
finally{
try{
cf.close();
}
catch(Exception e)
{
e.printStackTrace();
}
}
}
}
关键词：数据库连接池Java完成小结