使用代理创建连接池 proxyPool

配置文件properties

url=jdbc:mysql://127.0.0.1:3306/mine?characterEncoding=UTF-8

user=root

password=1234

driverClass=com.mysql.jdbc.Driver

主要代码

 package JDBCUtils;

 import java.io.IOException;
 import java.io.InputStream;
 import java.lang.reflect.InvocationHandler;
 import java.lang.reflect.Method;
 import java.lang.reflect.Proxy;
 import java.sql.Connection;
 import java.sql.DriverManager;
 import java.util.LinkedList;
 import java.util.Properties;
 /**
  * 使用代理创建连接池
  * @author ASUS
  *
  */
 public class ProxyConnUtils {

     private static LinkedList<Connection> pool =  new LinkedList<>();
     private static String url;
     private static String user;
     private static String password;
     private static String driverClass;
     //private static Connection conn;
     static{
         try {
             Properties properties = new Properties();
             InputStream in = ProxyConnUtils.class.getResourceAsStream("/db.properties");
             properties.load(in);
             url = properties.getProperty("url");
             System.err.println(url);
             user = properties.getProperty("user");
             password = properties.getProperty("password");
             driverClass = properties.getProperty("driverClass");
             Class.forName(driverClass);
             for(int i = 0;i<3;i++){
                 final Connection conn = DriverManager.getConnection(url, user, password);
                 //对connection做代理
                 Object connProxy = Proxy.newProxyInstance(ProxyConnUtils.class.getClassLoader(),
                     new Class[]{Connection.class},
                     new InvocationHandler() {

                         @Override
                         public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
                             //判断是否是close方法   回收连接
                             if(method.getName().equals("close")){
                                 synchronized (pool) {
                                     System.err.println("不能关闭");
                                     pool.addLast((Connection) proxy);
                                     pool.notify();
                                     return null;
                                 }
                             }else{
                                 //若果调用的不是close方法  直接放行
                                 return method.invoke(conn, args);
                             }
                         }
                     });
                 // 将代理对象添加到池中去
                 pool.add((Connection) connProxy);
             }
         } catch (Exception e) {
             e.printStackTrace();
             throw new RuntimeException(e);
         }
     }

     //获取connection连接
     public static Connection getConnection(){
         synchronized (pool) {
             if(pool.size() == 0){
                 try {
                     pool.wait();
                 } catch (Exception e) {
                     e.printStackTrace();
                     throw new RuntimeException(e);
                 }
             }
             Connection connection = pool.removeFirst();
             return connection;
         }
     }
 }

测试代码

 package JDBCTest;
 import java.sql.Connection;
 import java.sql.Statement;
 import java.util.Scanner;
 import JDBCUtils.ConnUtil;
 import JDBCUtils.ConnUtils;
 import JDBCUtils.ProxyConnUtils;
 public class Demo01_tx3 {
     class one extends Thread{
         @Override
         public void run() {
             System.err.println("1:获取连接");
             Connection con =
                     ProxyConnUtils.getConnection();
             try{
                 System.err.println("2:打开事务");
                 con.setAutoCommit(false);
                 System.err.println("3:写入Jack");
                 Statement st = con.createStatement();
                 st.execute("insert into money(id,name) values(1,'Jack')");
                 System.err.println("4:提交  ..");
                 con.commit();
             }catch(Exception e){
                 e.printStackTrace();
             }finally {
                 try {
                     System.err.println("5:关闭连接");
                     con.setAutoCommit(true);
                     con.close();
                 } catch (Exception e) {
                     e.printStackTrace();
                 }
             }
         };
     };

     public Demo01_tx3() {
         for(int i=0;i<5;i++){
             new one().start();
         }
     }

     public static void main(String[] args) {
         new Demo01_tx3();
     }
 }

运行结果