Rethrowing Exception in JAVA

 A Java exception is an object that describes an exceptional (that is, error) condition that has

occurred in a piece of code. When an exceptional condition arises, an object representing

that exception is created and thrown in the method that caused the error. That method may

choose to handle the exception itself, or pass it on. Either way, at some point, the exception

is caught and processed. Exceptions can be generated by the Java run-time system, or they

can be manually generated by your code. Exceptions thrown by Java relate to fundamental

errors that violate the rules of the Java language or the constraints of the Java execution

environment. Manually generated exceptions are typically used to report some error condition

to the caller of a method.

Java exception handling is managed via five keywords: try, catch, throw, throws, and

finally. Briefly, here is how they work. Program statements that you want to monitor for

exceptions are contained within a try block. If an exception occurs within the try block, it is

thrown. Your code can catch this exception (using catch) and handle it in some rational manner.

System-generated exceptions are automatically thrown by the Java run-time system. To

manually throw an exception, use the keyword throw. Any exception that is thrown out of

a method must be specified as such by a throws clause. Any code that absolutely must be

executed after a try block completes is put in a finally block.

//Rethrowing Exception in JAVA

class ExceptionDemo

{

static void divide(int a,int b)

{

try

{

System.out.println("a/b = "+a/b);

}

catch(ArithmeticException e)

{

System.out.println("ArithmeticException caught in divide");

System.out.println("Rethrowing e");

throw e;

}

}

public static void main(String args[])

{

try

{

divide(10,2);

divide(20,0);

}

catch(ArithmeticException e)

{

System.out.println("ArithmeticException Caught in main");

}

}

}