package com.myapp.patterns.creational;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class TestSingleton {

    private static TestSingleton instance=null;
    private TestSingleton() {
        // TODO Auto-generated constructor stub
    }

    public static TestSingleton getInstance(){

        synchronized (TestSingleton.class) {

            if(instance == null){
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {

                    e.printStackTrace();
                }
                instance=new TestSingleton();
            }
            return instance;
        }
    }

private static final String url="jdbc:mysql://localhost:3306/citrix";

    private static final String username="admin";

    private static final String password="admin";

    private Connection connection=null;


    public Connection getConnection() throws SQLException{

        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        if(connection==null || connection.isClosed()){


    synchronized (TestSingleton.class) {

                if(connection==null || connection.isClosed()){
                connection=DriverManager.getConnection(url, username, password);
                }
            }
        }
        return connection;
    }

    static TestSingleton instance1=null;
    static TestSingleton instance2=null;
    public static void main(String[] args) {




    Runnable task1=()->{
         instance1=TestSingleton.getInstance();

    };

    Runnable task2=()->{
         instance2=TestSingleton.getInstance();

    };


    Thread t1=new Thread(task1);
    Thread t2=new Thread(task2);

    t1.start();
    t2.start();


        try {
            t1.join();
            t2.join();
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        System.out.println(instance1 == instance2);
        try {
            Connection con1=instance1.getConnection();
            Connection con2=instance2.getConnection();
            System.out.println(con1==con2);
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

    }

}