Doubt in Exception Handling.

[Suresh Rajadurai]

Hi Folks,

Please see the following 2 programs. could you please explain me why program 1 is giving compilation errors(complaining that it is expecting catch block) while program 2 is working fine without the catch block.

Only difference is , method in program 1 is void return type, whereas method in program 2 is integer return type. Is it permitted to avoid having a catch block in the method if the return type of the method is NOT void? I am confused.

Program 1:

class test
   {
	public static void main(String arg[])
	   {
		new test().method();
	   }

	void method()
	   {
		try
		 {
			throw new Exception("throwing");
		 }
		finally
		 {
			System.out.println("hello");
		 }		
	   }

   }

Program 2:

class test
   {
	public static void main(String arg[])
	   {
		System.out.println(new test().method());
	   }


	int method()
	   {
		try
		 {
			throw new Exception("throwing");
		 }
		finally
		 {
			System.out.println("hello");
			return 2;
		 }		
	   }

   }

Much appreciated,

thanks in advance,

Suresh.

[Ankit Garg]

Well the first program is going to throw a checked exception to the calling method. So you need to either catch it or use a throws clause with the method. The second code will also throw a checked exception, but the return statement in the finally block will suppress that exception. So you don't need a catch block. I would recommend that you try these two modified versions of the first program

class test
{
   public static void main(String arg[]) throws Exception
   {
	  new test().method();
   }
   void method() throws Exception
   {
	try
	 {
		throw new Exception("throwing");
	 }
	 finally
	 {
		System.out.println("hello");
	 }		
   }
}

class test
{
public static void main(String arg[])
   {
	  new test().method();
   }

   void method()
   {
	try
	 {
		throw new Exception("throwing");
	 }
	 finally
	 {
		System.out.println("hello");
		return;
	 }		
   }
}

[mansi gupte]

new test().method(); is it a valid statement?

[Vijitha Kumara]

piya rai wrote:new test().method(); is it a valid statement?

well, what do you think it should be?

[Vikas Kapoor]

piya rai wrote:new test().method(); is it a valid statement?

It's perfectly valid statement.
you can think it in this way also.

test testObject = new test();
testObject.method();