连接错误，说我con关闭，但是我并没有
com.mysql.jdbc.exceptions.MySQLNonTransientConnectionException: Data source rejected establishment of connection, message from server: "Too many connections"
并且，我的模拟购买好像失效了

全部代码
package Test;

import java.sql.*;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.atomic.AtomicInteger;
public class IncrTest {
//声明Connection对象
static Connection con;
//驱动程序名
static String driver = "com.mysql.jdbc.Driver";
//URL指向要访问的数据库名mydata
static String url = "jdbc:mysql://localhost:3306/test";
//MySQL配置时的用户名
static String user = "root";
//MySQL配置时的密码
static String password = "root";

public static void RunMethod(){

    //遍历查询结果集
    try {
        //加载驱动程序
        Class.forName(driver);
        //1.getConnection()方法，连接MySQL数据库！！
        con = DriverManager.getConnection(url,user,password);
        //2.创建statement类对象，用来执行SQL语句！！
        Statement statement = con.createStatement();
        //要执行的SQL语句
        String sql = "update goods set num = num -1  where id = 1 and num>0 for update ";
        Integer num = statement.executeUpdate(sql);
    } catch(ClassNotFoundException e) {
        //数据库驱动类异常处理
        System.out.println("Sorry,can`t find the Driver!");
        e.printStackTrace();
    } catch(SQLException e) {
        //数据库连接失败异常处理
        e.printStackTrace();
    }catch (Exception e) {
        // TODO: handle exception
        e.printStackTrace();
    }finally{
        System.out.println("数据库数据成功获取！！");
    }
}
public static void concurrenceTest (){
    /**
     * 模拟高并发情况代码
     */
    final AtomicInteger atomicInteger = new AtomicInteger(0);
    final CountDownLatch countDownLatch = new CountDownLatch(1000); // 相当于计数器，当所有都准备好了，再一起执行，模仿多并发，保证并发量
    final CountDownLatch countDownLatch2 = new CountDownLatch(1000); // 保证所有线程执行完了再打印atomicInteger的值
    ExecutorService executorService = Executors.newFixedThreadPool(10);
    try {
        for (int i = 0; i < 1000; i++) {
            executorService.submit(new Runnable() {
                @Override
                public void run() {
                    try {
                        countDownLatch.await(); //一直阻塞当前线程，直到计时器的值为0,保证同时并发
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                    //每个线程增加1000次，每次加1
                    for (int j = 0; j < 1000; j++) {
                        //atomicInteger.incrementAndGet();
                        //购买商品
                        RunMethod();
                    }
                    countDownLatch2.countDown();
                }
            });
            countDownLatch.countDown();
        }

        countDownLatch2.await();// 保证所有线程执行完
        System.out.println(atomicInteger);
        executorService.shutdown();
    }catch (Exception e){
        e.printStackTrace();
    }
}

public static void main(String[] args) throws InterruptedException {
    concurrenceTest();
}

}