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try, catch, finally - full example
Exceptions example from a Well House Consultants training course
More on Exceptions [link]

This example is described in the following article(s):
   • Fail Safe Error Handling in Java via Exceptions - [link]
   • After Course Resources - do we publish sample answers. Example from Java Exceptions module. - [link]

Source code: Keira.java Module: J712
/* This is a complete example (when read in conjunction with the class "Jane"
which is in the same directory on our server) showing the running of a piece
of code and the catching of a variety of exceptions - standard ones, ones you
have defined yourself, etc.

The example also shows you how clean up code goes in a finally block, and how
a method can handle exceptions itself, or can return them (throw them up) to
the calling method. */

// Exceptions ...
// A "Jane" is one of our own exceptions - thrown if a number is too large

public class Keira {

// methods can handle their own problems or, in as here, call on their
// parent to help them. (like children, really!)

        static int getval(String instuff) throws Exception {
                int result = Integer.parseInt(instuff);
                if (result > 40) {
                                Jane Jones = new Jane();
                                throw Jones;
                return result;

        public static void main (String [] args) {
                int inval = 0;
                try {
                        inval = getval(args[0]) ;
                catch (Jane e) {
                        System.out.println("I have a concern: "+e.getMessage());
                        inval = 39; // Force a fallback value.
                                        // No "return" do DO proceed
                catch (Exception e) {
                        System.out.println("I have a problem: "+e.getMessage());
                                // Should probably add type of exception to message!
                        return; // do NOT process to rest of method
                finally { // Happens whether or not we proceed!
                        System.out.println("I'm cleaning up");
                System.out.println("SUCCESS ... Here we go ...");
                System.out.println("" + inval + " + 3 is " + (inval +3));


wizard:java graham$ java Keira
I have a problem: 0
I'm cleaning up

wizard:java graham$ java Keira 4
I'm cleaning up
SUCCESS ... Here we go ...
4 + 3 is 7

wizard:java graham$ java Keira four
I have a problem: For input string: "four"
I'm cleaning up

wizard:java graham$ java Keira 44
I have a concern: OOhh - Tarzan!
I'm cleaning up
SUCCESS ... Here we go ...
39 + 3 is 42


Learn about this subject
This module and example are covered on the following public courses:
 * Learning to Program in Java
 * Java Bootcamp
 * Java Programming for the Web
Also available on on site courses for larger groups

Books covering this topic
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Other Examples
This example comes from our "Exceptions" training module. You'll find a description of the topic and some other closely related examples on the "Exceptions" module index page.

Full description of the source code
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