Thread

 package com.citibank.aimy.Examples.serialize; public class MainThread { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub ProductBox b = new ProductBox(); Producer p = new Producer(b); Consumer c = new Consumer(b); p.setPriority(Thread.MAX_PRIORITY); p.start(); c.start(); // Product[] ls = new Product[6]; // System.out.print(ls.length); } }

package com.citibank.aimy.Examples.serialize; public class Producer extends Thread { private ProductBox b; public Producer(ProductBox box){ this.b = box; } public void run(){ for(int i=0;i<10;i++){ Product p = new Product("Product::"+i); b.push(p); } try { Thread.sleep((long) (Math.random()*200)); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }

package com.citibank.aimy.Examples.serialize; public class Product { public Product(int id){ this.id = id; } public Product(String name){ this.name = name; } private String name; private String color; private String scale; private int id; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getColor() { return color; } public void setColor(String color) { this.color = color; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getScale() { return scale; } public void setScale(String scale) { this.scale = scale; } } package com.citibank.aimy.Examples.serialize; import java.util.ArrayList; public class ProductBox { private ArrayList ls = new ArrayList(); private int index = 0; //create 4 products one time. public synchronized void push(){ while(index<10){ while(index==8) try { this.wait(); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } System.out.println("produce a new product:::"+index); Product p = new Product(index); ls.add(p); System.out.println("add a new product:::"+((Product)ls.get(index)).getId()); index++; this.notify(); } } public synchronized void push(Product p){ while(index<10){ while(index==8)// try { this.wait(); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } //System.out.println("produce a new product:::"+index); ls.add(p); System.out.println("add a new product:::"+((Product)ls.get(index)).getName()); index++; this.notify(); } } public synchronized void pop(){ while(index<10){ while(index==0) try { this.wait(); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } //System.out.println("comsume a new product:::"+(index-1)); Product r = (Product) ls.remove(index-1); System.out.println("remove a new product:::"+r.getName()); index--; this.notify(); } } }

package com.citibank.aimy.Examples.serialize; public class Consumer extends Thread { private ProductBox b; public Consumer(ProductBox box){ this.b = box; } public void run(){ for(int i=0;i<10;i++){ b.pop(); } try { Thread.sleep((long) (Math.random()*200)); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }

 

In Producer.run(), the for-loop will never increment i to 1. As whenever the productBox add the product 8 times leaving index to be 8, it waits until the consumer consumes all the 8 product, leaving the index to be 0 again, and the producer wakes up to see that index is again 0 and do it again. It will forever loop and never stop.