Ant: Java Swing Hello World in Ant

This is the fifth part of the so called Ant series I have been writing in this blog, about Apache Ant. This post is mainly about building and running a Java Swing program using Ant.

The previous posts on Ant can be found here:

1. Apache Ant
2. Ant: Installation
3. Ant: Hello World in Ant
4. Ant: Java Hello World in Ant

Java Swing Program

Create the following simple swing program and save it as HelloWorldSwing.java in a sub folder src:

import javax.swing.JFrame;import javax.swing.JLabel;

public class HelloWorldSwing {public static void main(String[] args) {JFrame frame = new JFrame("HelloWorldSwing");final JLabel label = new JLabel("Hello World");frame.getContentPane().add(label);frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);frame.pack();frame.setVisible(true);   }}

Ant Script

Use a text editor to create a file called build.xml and place it in the main folder:

<?xml version="1.0" encoding="UTF-8"?><project name="Run Test" default="run" basedir=".">

<target name="clean">   <delete dir="build"/></target>

<target name="compile" depends="clean">   <mkdir dir="build/classes"/>   <javac srcdir="src" destdir="build/classes"/></target>

<target name="jar" depends="compile">   <mkdir dir="build/jar"/>   <jar destfile="build/jar/HelloWorldSwing.jar" basedir="build/classes">       <manifest>           <attribute name="Main-Class" value="HelloWorldSwing"/>       </manifest>   </jar></target>

<target name="run" depends="jar">   <java jar="build/jar/HelloWorldSwing.jar" fork="true"/></target>

</project>

Outputs and Problems

When we run this is text mode it, it compiles but fails to run. But when in GUI it runs.

[root@sanjaya-vm ant-swing]# antBuildfile: build.xml

clean:[delete] Deleting directory /opt/ant-swing/build

compile:[mkdir] Created dir: /opt/ant-swing/build/classes[javac] Warning: HelloWorldSwing.java modified in the future.[javac] Compiling 1 source file to /opt/ant-swing/build/classes

jar:[mkdir] Created dir: /opt/ant-swing/build/jar[jar] Building jar: /opt/ant-swing/build/jar/HelloWorldSwing.jar

run:......[java] at java.awt.Window.<init>(Window.java:406)[java] at java.awt.Frame.<init>(Frame.java:402)[java] at javax.swing.JFrame.<init>(JFrame.java:207)[java] at HelloWorldSwing.main(Unknown Source)[java] Java Result: 1

BUILD SUCCESSFULTotal time: 3 seconds

This is one another basic level post and I strongly advice you to refer to any more advanced document, if you are going to do this for any production system.

Feedback and questions are welcome via comment or you can email me at talkout AT SPAMFREE gmail DOT com