Step by step instructions of how to build and run java code as a normal application, as a java web start application and as an applet.

Replace with newer code and add file names!

It is advisable to separate core functionality from the final deployment mechanism:

import javax.swing.*;
 
public class MyApplication extends JFrame {
 
    private void createAndShowGUI() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setTitle("My App Title");
        JPanel panel= new MyContent();  /* get app-specific content  */
        getContentPane().add(panel);    /* and put it into app frame */
        pack();
        setVisible(true);
    }
 
    public static void main(String[] args) {
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                MyApplication frame = new MyApplication();
                frame.createAndShowGUI();
            }
        });
    }
}

The usage of SwingUtilities.invokeLater is used by Sun as well.

import javax.swing.*;
 
public class MyApplet extends JApplet {
    public void init() {
        try {
            SwingUtilities.invokeAndWait(new Runnable() {
                public void run() {
                    JPanel panel= new MyContent();/* create app-specific */
                    add(panel);     /* content and put it into app frame */
                }
            });
        } catch (Exception e) {
            System.err.println("createGUI didn't complete successfully");
        }
    }
}

import javax.swing.*;
 
public class MyContent extends JPanel {
    private JLabel myLabel;
 
    MyContent() {
        myLabel= new JLabel("¡Hola Mundo!");
        add(myLabel);
    }
}

Structure:

.
|-- build
|   `-- classes
|       |-- PjpApplication.class
|       `-- PropsPanel.class
`-- src
    `-- pjp
        |-- PjpApplication.java
        `-- PropsPanel.java

The compile command is: (The destination path must exist!)

javac -sourcepath src/pjp -d build/classes src/pjp/PjpApplication.java

The run command is:

java -cp build/classes PjpApplication

Structure:

.
|-- build
|   `-- classes
|       `-- pjp
|           |-- PjpApplication.class
|           `-- PropsPanel.class
`-- src
    `-- pjp
        |-- PjpApplication.java
        `-- PropsPanel.java

Include package pjp; at the beginning of both source files.

The compile command is: (Note that the dir pjp in build/classes ist generated automatically)

javac -sourcepath src -d build/classes/ src/pjp/PjpApplication.java

The run command is:

java -cp build/classes pjp.PjpApplication

More on packages

Create a dir for jar files: mkfile build/jar

Add a manifest file, e.g. application.manifest and specify the main class as entry point:

Main-Class: pjp.PjpApplication

Structure:

.
|-- application.manifest
|-- build
|   |-- classes
|   `-- jar
`-- src
    `-- pjp
        |-- PjpApplication.java
        `-- PropsPanel.java

Compile the sources like above and then create the jar file:

jar cfm build/jar/pjpApplication.jar application.manifest -C build/classes .

-C build/classes . means: Cd to build/classes and archive all files there. (Just type jar to get jar help)

The run command is:

java -jar build/jar/pjpApplication.jar

<project name="Pjp" default="maintarget">
    <property name="src.dir"     value="src"/>
    <property name="build.dir"   value="build"/>
    <property name="classes.dir" value="${build.dir}/classes"/>
    <property name="jar.dir"     value="${build.dir}/jar"/>
    <property name="application" value="${ant.project.name}Application"/>
 
    <target name="clean">
        <delete dir="${build.dir}"/>
    </target>
 
    <target name="compile">
        <mkdir dir="${classes.dir}"/>
        <javac srcdir="${src.dir}" destdir="${classes.dir}"/>
    </target>
 
    <target name="jar" depends="compile">
        <mkdir dir="${jar.dir}"/>
        <jar destfile="${jar.dir}/${application}.jar" basedir="${classes.dir}">
            <manifest>
                <attribute name="Main-Class" value="pjp.${application}"/>
            </manifest>
        </jar>
    </target>
 
    <target name="run" depends="jar">
        <java jar="${jar.dir}/${application}.jar" fork="true"/>
    </target>
 
    <target name="maintarget" depends="clean,run"/>
</project>

See also Tutorial: Hello World with Ant

Project Structure:

.
|-- build.xml
|-- jws.html
|-- pjp-jws.jnlp
`-- src
    `-- pjp
        |-- PjpApplet.java
        |-- PjpApplication.java
        `-- PropsPanel.java

pjp-jws.jnlp:

<?xml version="1.0" encoding="UTF-8"?>
<jnlp spec="1.0+"
    codebase="http://etb-111.kaeser-net.de/~becki/test/printJavaProps"
    href="pjp-jws.jnlp">
    <information>
        <title>Info Title</title>
        <vendor>Info Vendor</vendor>
    </information>
    <resources>
        <j2se version="1.6+" href="http://java.sun.com/products/autodl/j2se"/>
        <jar href="build/jar/PjpApplication.jar" main="true" />
    </resources>
    <application-desc
         name="application-desc name"
         main-class="pjp.PjpApplication"
         width="500"
         height="200">
     </application-desc>
     <update check="background"/>
</jnlp>
<xml>
 
jws.html contains:
<code html>
<a href="pjp-jws.jnlp">Launch Webstart Application</a>

Create applet.manifest:

Main-Class: pjp.PjpApplet

add Ant task

<applet code="pjp.PjpApplet" archive="build/jar/pjpApplet.jar" width="500" height="200"></applet>

Note that there are more sophisticated ways to deploy an applet!

http://ant.apache.org/manual/tutorial-HelloWorldWithAnt.html#ext-libs http://ant.apache.org/manual/dirtasks.html (Manual → Ant Tasks → Core Tasks → Concepts and Types → Directory-based Tasks - How very easy to find!!)