public class ReadThread implements Runnable{

     

     TableControl tc;

     

     public ReadThread(TableControl tc){

         this.tc=tc;

     };

     @Override

     public void run() {

         tc.readLock().lock();

         System.out.println("ReadThread");

         tc.get();

         tc.readLock().unlock();

     }

}





















 public class WriteThread implements Runnable{
     
     TableControl tc;
     
     public WriteThread(TableControl tc){
         this.tc=tc;
     };
     @Override
     public void run() {
         tc.writeLock().lock();
         System.out.println("WriteThread");
         tc.add(100);
         tc.writeLock().unlock();
     }


 }

















import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReadWriteLock;
 import java.util.concurrent.locks.ReentrantReadWriteLock;




 public class TableControl {




     private ReadWriteLock readWriteLock = new ReentrantReadWriteLock();;




     private int i = 0;




     public void get() {
         System.out.println(i);
         writeLock().lock();
         System.out.println(System.currentTimeMillis());
         add(50);
         writeLock().unlock();
         try {
             Thread.sleep(2000);
         } catch (InterruptedException e) {
             e.printStackTrace();
         }
     }
     
     public void add(int v) {
         i += v;
         System.out.println(i);
         try {
             Thread.sleep(2000);
         } catch (InterruptedException e) {
             e.printStackTrace();
         }
     }




     public Lock readLock() {
         return readWriteLock.readLock();
     }




     public Lock writeLock() {
         return readWriteLock.writeLock();
     }




 }

















public class TestMain {


    
     public static void main(String args[]){
        
         
         TableControl tc=new TableControl();
         WriteThread wt=new WriteThread(tc);
         ReadThread rt=new ReadThread(tc);        
         
         Thread t1 =new Thread(wt);
         Thread t2 =new Thread(rt);
         
         
         t2.start();
        // t1.start();
         
         
     }




     
 }