Program Multi Thread (JAVA)

//program multi Thread
class MyThread1 extends Thread
{
public void run()
{
try
{
for (int i=0; i<10; i++)
{
System.out.println("Thread pertama : detik ke-" + (i+1));
if (i !=4)
{
System.out.println();
sleep(1000);
}
else
{
System.out.println("Thread pertama selesai...\n");
}
}
}
catch (InterruptedException ie)
{
System.out.println(ie.getMessage());
}
}
}
class MyThread2 extends Thread
{
public void run()
{
try
{
for (int i=0; i<5; i++)
{
System.out.println("Thread kedua : detik ke-" + (i+1));
if (i !=4)
{
System.out.println();
sleep(1000);
}
else
{
System.out.println("Thread kedua selesai...\n");
}
}
}
catch (InterruptedException ie)
{
System.out.println(ie.getMessage());
}
}
}
class DemoMultiplethread
{
public static void main(String[]args)
{
MyThread1 t1 = new MyThread1();
t1.start();

MyThread2 t2 = new MyThread2();
t2.start();
}
}