package cn.itcast.utils;
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;
public class ConnUtils {
      //使用LinedList加快存取速度
      private static LinkedList<Connection> pool = new LinkedList<Connection>();
      static{
            try{
                  Class.forName("com.mysql.jdbc.Driver");
                  String url = "jdbc:mysql:///itcast?characterEncoidng=UTF8";
                  for(int i=0;i<3;i++){
                        final Connection con = DriverManager.getConnection(url,"root","1234");
                        Object proxedObj =
                        Proxy.newProxyInstance(
                        ConnUtils.class.getClassLoader(),
                  new Class[]{Connection.class},
                        new InvocationHandler() {
                              public Object invoke(Object proxy, Method method, Object[] args)
                              throws Throwable {
                                    //判断是否调用的是closre方法
                                    if(method.getName().equals("close")){
                                          System.err.println("有人还连接...");
                                          synchronized (pool) {
                                                pool.addLast((Connection) proxy);
                                                pool.notify();
                                          }
                                          return null;
                                    }
                                    return method.invoke(con, args);
                              }
                        });
                        //将代理放到池中
                        pool.add((Connection) proxedObj);
                  }
            }catch(Exception e){
            e.printStackTrace();
      }
}
public static Connection getCon(){
      synchronized (pool) {
            if(pool.size()==0){
                  try {
                        pool.wait();
                  } catch (InterruptedException e) {
                        e.printStackTrace();
                  }
                  return getCon();
            }else{
            return pool.removeFirst();
      }
}
}
}