Using Aspects to Autonomic-Enable Legacy Applications

By Brian Temple
2005-05-13


Example legacy application
I'll start with a very simple application to demonstrate legacy autonomic enablement. The application used is a variation on the "Hello World" code, which contains an encapsulated variable and makes several method calls in its execution.

Listing 1. HelloWorld.java

package com.mycompany.myapp;



public class HelloWorld {

    private String helloWorldString = "Hello World";



    public static void main(String[] args) {

        HelloWorld helloWorld = new HelloWorld();

        helloWorld.run();

    }



    public void run() {

        String helloWorldString = getHelloWorldString();

        System.out.println(helloWorldString);

        setHelloWorldString("Goodbye World");

        helloWorldString = getHelloWorldString();

        System.out.println(helloWorldString);

    }

    

    public String getHelloWorldString() {

        return helloWorldString;

    }



    public void setHelloWorldString(String helloWorldString) {

        this.helloWorldString = helloWorldString;

    }

}

This application contains one source directory and is built using Ant, as shown in Listing 2.

Listing 2. Original Ant Build Script

...

<javac srcdir="src/" destdir="build">

    <include name="com/**/*"/>

</javac>

...

Tutorial Pages:
» Using Aspects to autonomic-enable legacy applications
» Introduction
» Example legacy application
» Incorporating Aspects
» An example Aspect framework to generate Common Base Events
» How to use and extend the example Aspect framework
» Next steps
» Resources


First published by IBM DeveloperWorks

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