difference between throw and throws

[satellite03]

hi, are these throw and throws are two different keywords in java?? if so, when throw is usued and when throws is usued?

any small code plz...
thanks

 

[satellite03]

....in case of ioexception i have usued public static void main(String args[])throws IOException ..

 

[sedj]

Hope these examples clear it up for you :

public void myMethod() throws IOException {
    FileInputStream fis = new FileInputStream();
    fis.read();
}

OR

public void myMethod() throws CustomException {
  try {
    FileInputStream fis = new FileInputStream();
    fis.read();
  } catch (IOException ioe) {
      ioe.printStackTrace();

      throw new CustomException("Causgt an IOException but am throwing this CustomException instead");
  }
}

 

[Diancecht]

RTFM

http://java.sun.com/docs/books/tutorial/essential/exceptions/throw.html

 

[satellite03]

hi, i have come to conclusion that throw usued basically for user-defined exception.......
i tested

import java.lang.Exception;
class MyException extends Exception
{
	MyException (String message)
	{
		super(message);
	}
	
}

class TestMyException
{	public static void main(String args[])
	{  int x = 5,y = 1000;
		try
		{ float z =(float) x /(float)y ;
			if(z<0.01)
			{
				throw new MyException(&quot;number is too small&quot;);
			}
			
		}
		catch(MyException e)
		{ 
			System.out.println(&quot;caught my exception&quot;);
			System.out.println(e.getMessage() );
		}
		
		finally
		{
			System.out.println(&quot;I am always here&quot;);
		}
		
	}
	
}

and about throws ..it basically used in the function header and usues standard exception handler classes.

thanks

 

[Diancecht]

Yupp, that's the basic idea.

Anyway, you can throw any exception, not just user defined

Cheers.

Dian