try without catch?

[Drew Lane]

Under what circumstances would we use a try block
without a catch block?
Would a finally block be required in this situation?
Thanks!
Drew

[Angela Narain]

Yes , the try block has to followed by atleast a catch ( more than one if required ) OR a
finally block.

[Drew Lane]

OK, but when would you actually use a try/finally without a catch?
try{
// code that might throw an exception
}
finally{
// do something here
}
If the code in the try block throws a checked exception wouldn't it require the use of a catch block anyway?
Regards,
Drew

[Anonymous]

Hi Drew!
I'll try to illustrate this w/ a lil snippet:

import java.io.*;
class NoCatch {
  NoCatch(String path) throws FileNotFoundException {
    System.out.println("------------------------");
    System.out.println("NoCatch(" + path + ")");
    try {
      new FileReader(path);
    }
    finally {
      System.out.println("CTOR always does");
    }
    System.out.println("CTOR sometimes does");
  }
  static void main(String[] args) throws FileNotFoundException {
    try {
      NoCatch obj = new NoCatch("NoCatch.java");
      obj = new NoCatch("Bad.File");
    }
    finally {
      System.out.println("Did something...");
    }
    System.out.println("All Ok!"); // this line does not execute if Bad.File fails
  }
}

So we can delegate error handling to higher scope, but yet we can do some things in finally blocks. Snippet has the idea but isnt very good example for this.
------------------
Antti Barck
It Solutions Consultant -- NSD Oy
Sun Certified Programmer for the Java™ 2 Platform

[Cameron Park]

You can use try/finally without a catch block. Usually, you just want to release some non-memory resources allocated in the try block, and you want to make sure that these resources will be released no matter what. You use try/finally block to accomplish that.

[Anonymous]

Helo Cameron!
That was much better example.
------------------
Antti Barck
It Solutions Consultant -- NSD Oy
Sun Certified Programmer for the Java™ 2 Platform

[Muhammad Farooq]

I just want to add one more thing, if there is no catch block or specific or related catch block (of super class of the exception raised) then the Exception is said to be uncaught and method terminate after final block.
--Farooq
[This message has been edited by Muhammad Farooq (edited August 27, 2001).]