can anyone explain me this code

Question

class Customer{  

int amount=10000;  

synchronized void withdraw(int amount){  

System.out.println("going to withdraw...");  

if(this.amount<amount){  

System.out.println("Less balance; waiting for deposit...");  

try{wait();}catch(Exception e){}  

}  

this.amount-=amount;  

System.out.println("withdraw completed...");  

}  

synchronized void deposit(int amount){  

System.out.println("going to deposit...");  

this.amount+=amount;  

System.out.println("deposit completed... ");  

notify();  

}  

}  

class Test{  

public static void main(String args[]){  

final Customer c=new Customer();  

new Thread(){  

public void run(){c.withdraw(15000);}  

}.start();  

new Thread(){  

public void run(){c.deposit(10000);}  

}.start();  

}}  

Answer 1

Looks like they are trying to create a customer class and objects that can deposit and withdraw amounts (of money). It seems to be designed to work in a multi threaded setting where the withdrawal operation has to wait to be notified by a deposit operation. However, as it is written I don't believe this program will work without some modification. A Java expert might be able to better explain. Danijel Ivanović ??

Answer 2

it works, it outputs:

going to withdraw...
Less balance; waiting for deposit...
going to deposit...
deposit completed...
withdraw completed...

it shows how wait() / notify() methods works

first c.withdraw() on thread try take out 15000$ but there is only 10000$
so withdraw() thread go to wait() state.

then main() start() next thread of the same object c.deposit()
deposit() add 10000$ (now there is 20000$)

deposit() then do notify() and because it is same object c.withdraw() method wake and continue its work and take out 15000$.