package cn.hc.connectionPool;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.LinkedList;
import java.util.Properties;
/**
* 简单的MySql数据库连接池
* @author hc
* @version 1.0
*/
public class ConnectionPool {
private LinkedList<Connection> connections=
new LinkedList<Connection>
();
//默认的数据库连接池大小为5
private static int initSize=5
;
private static int maxSize=5
;
private int acturalSize=0;
//数据库连接池的实际大小
private static Properties props =
null;
static{
try {
InputStream in = ConnectionPool.
class.getClassLoader()
.getResourceAsStream("dbconfig.properties"
);
props =
new Properties();
props.load(in);
} catch(IOException e) {
throw new RuntimeException(e);
}
try {
String size=props.getProperty("initSize"
);
String size2=props.getProperty("maxSize"
);
if(size!=
null){
initSize=
Integer.parseInt(size);
}
if(size2!=
null){
maxSize=
Integer.parseInt(size2);
}
} catch (Exception e) {
throw new RuntimeException(e);
}
}
//获取连接的静态内部类
static class GetCon{
static{
try {
Class.forName(props.getProperty("driverClassName"
));
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
static Connection getConnection()
throws SQLException{
return DriverManager.getConnection(props.getProperty("url"
),
props.getProperty("username"
),
props.getProperty("password"
));
}
}
public ConnectionPool(){
//初始化数据库连接池
for (
int i = 0; i<initSize; i++
) {
try {
connections.addLast(GetCon.getConnection());
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
acturalSize++
;
}
}
/**
* 该方法用来释放连接，将connection对象放回到数据库连接池,实现对数据库连接池大大小的增减
* @param connection 要放回数据库连接池的连接
*/
public void releseConnection(Connection connection){
if(connection!=
null){
synchronized (connections) {
if(connections.size()>
initSize){
try {
connection.close();
acturalSize--
;
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}else{
connections.addLast(connection);
}
connections.notifyAll();//唤醒所有等待获取连接的对象
}
}
}
/**
* 该方法用来从数据库连接池获取连接
* @param mills 获取连接的超时时间 单位毫秒,当设置的值为0时候，即不要求等待时间
* @return connection对象
* @throws SQLException
* @throws InterruptedException
*/
public Connection getConnection(
long mills)
throws SQLException, InterruptedException{
synchronized (connections) {
if(mills<=0
){
while (connections.isEmpty()) {
if(acturalSize<
maxSize){
Connection con= DriverManager.getConnection(props.getProperty("url"
),
props.getProperty("username"
),
props.getProperty("password"
));
acturalSize++
;
return con;
}else{
connections.wait();
}
}
return connections.removeFirst();
}else{
if(acturalSize<
maxSize){
Connection con= DriverManager.getConnection(props.getProperty("url"
),
props.getProperty("username"
),
props.getProperty("password"
));
acturalSize++
;
return con;
}else{
long future=System.currentTimeMillis()+
mills;
long remaining=
mills;
while(connections.isEmpty()&&remaining>0
){
connections.wait(remaining);
remaining=future-
System.currentTimeMillis();
}
Connection result=
null;
if(!
connections.isEmpty()){
result=
connections.removeFirst();
}
return result;
}
}
}
}
}
配置文件：
driverClassName=
com.mysql.jdbc.Driver
url=jdbc\:mysql\:
//localhost\:3306/acled?rewriteBatchedStatements\=true
username=
root
password=123
initSize=5
maxSize=7
转载于:https://www.cnblogs.com/woolhc/p/5327782.html
