In simple words a static syncronized method will lock the class instead of the object, and it will lock the class because the keyword static means: "class instead of instance". The keyword syncronized means that only one thread can access the method at a time.

Example:

class Test
{
void show(int n)
{
	for(int i=1;i<=3;i++)
	{
		System.out.println(n*i);
		try
		{
		Thread.sleep(500);
		}
		catch(Exception e)
		{
		}
	}
}
}
class MyThread1 extends Thread
{
	public void run()
	{
		Test.show(2);
	}
}
class MyThread2 extends Thread
{
public void run()
{
	Test.show(3); 
}
class MyThread3 extends Thread3
{
	public void run()
	{
		Test.show(4);
	}
}
class MyThread4 extends Thread
{
	public void run()
	{
		Test.show(5);
	}
}
class StaticSynchronizeDemo
{
	public static void main(String[] args)
	{
		MyThread1 ob1= new MyThread1();
		MyThread2 ob2= new MyThread2();
		MyThread3 ob3= new MyThread3();
		MyThread4 ob4= new MyThread4();
		ob1.start();
		ob2.start();
		ob3.start();
		ob4.start();
	}
}

Output

2
4
6
3
6
9
4
8
12
5
10
15