As you have already heard about the extension (*.jnlp) which had made the java developer more easier to present their programs with a single file..

Actually the jnlp extension is a ext. of Sun Java. We can simply present the jnlp in both web(browser) and desktop .

The Web Start mechanism has made this jnlp to run at the top of Java 2 platform.

In this blog I’m going to show how can we make our program to display as a icon at Desktop and Start Menu.

As i’m just going through a sample jnlp file which is being resulted by NetBeans..see (how  to create jnlp from NetBeans).

Ok here is our JNLP code:

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<jnlp codebase="file:/C:/Users/JavaNep/Desktop/Sample/dist" href="launch.jnlp" spec="1.0+">
<information>
<title>Sample</title>
<vendor>javacoder</vendor>
<homepage href="http://javacoder.co.cc"/>
<description>Sample</description>
<description kind="short">Sample</description>

<offline-allowed/>
</information>
<security>
<all-permissions/>
</security>
<resources>
<j2se version="1.5+"/>
<jar eager="true" href="Sample.jar" main="true"/>

</resources>
<application-desc main-class="sample.Main">

</application-desc>
</jnlp>

(more details about jnlp….)
You can see it’s very simple one jnlp file, where there is only one jar file named Sample.jar and the main class file is Main.class which is represented at sample package (sample.Main).

For the icon at Desktop and Start Menu:-
Now our modified code goes here :

For Icon:

<icon href="logo.png" kind="default"/>

You can place your own icon image by specifying exact path of the icon in replace of logo.png  and if  your icon is in the dist folder then you can simply place the name of the file and extension like as in above example.

For Shortcut at Desktop and StartMenu:

<shortcut online="false">
	<desktop/>
	<menu submenu="Sample">
	<menu submenu="Sample Sub menu"/>
	</menu>
</shortcut>

Also If you want to keep splash screen then use this:

<icon href="load.png" kind="splash"/>

After all our complete modified jnlp file will be like as below code:

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<jnlp codebase="file:/C:/Users/Razer/Desktop/Sample/dist" href="launch.jnlp" spec="1.0+">
    <information>
        <title>Sample</title>
        <vendor>Razer</vendor>
        <homepage href=""/>
        <description>Sample</description>
        <description kind="short">Sample</description>

	<icon href="load.png" kind="splash"/>

	<icon href="logo.png" kind="default"/>

	<shortcut online="false">
		<desktop/>
			<menu submenu="Prabinas">
			<menu submenu="Product Managing System"/>
			</menu>
	</shortcut>
<offline-allowed/>
</information>
<security>
<all-permissions/>
</security>
    <resources>
<j2se version="1.5+"/>
<jar eager="true" href="Sample.jar" main="true"/>

    </resources>
    <application-desc main-class="sample.Main">

    </application-desc>
</jnlp>

Actually the jar files are the bundled file of all the classes, images and other resources which are need for running java application. Most of the JAR files are used for J2ME(Mirco Edition) purpose, i mean at Mobile Devices where java is compatible.
The JAR files can be easily made from numerous of processes but among them i’m going to demonstrate here through IDE NetBeans for creating JAR file and executable.

For making JAR files you must have following requirements:

1. Java preinstalled  (1.5 or greater)
2. Windows Platform
3. One Manual Project which contains Swing Component or Applet

Ok now let’s begin to Bundle our Files in JAR format.

Firstly run NetBeans and make one Project which displays GUI or just download a Sample Project for NetBeans

1. LoginPanel

Now Open the project which u downloaded or just use your own Project.

Press Ctrl+1 for enabling Project Tab and you can see your project there:

As shown in figure.

Now you can right click on the your Project Root and click Properties.

A new Dialog Box will appear.

STEP 1: Now expand Build tree and click on Packaging on Packaging you can see where the jar is to be saved.

On Default it keeps jar files at dist folder of our Project Directory.

STEP 2: Now Click on  to the Application tree and click Web Start now on right side you can see the check box

‘Enable Web Start’ check the box.

STEP 3: Move towards Run tree now you can specify which class you want to execute for jar file.

Change Main-Class: Class File(packageName.classFileYouWantToExecute)

foreg: loginpanel.Main

Specify the Class File you want to run or execute..

(For the LoginPanel project please type change loginpanel.Main to loginpanel.LoginPanel )

After specifying the class file you want to load then, make sure the option ‘Run with Java Web Start’ is checked.

After that Click on OK now you can Build your JAR file by pressing Shift+F11.

Now you can see a jar file in your directory (on default /dist) and open the JAR file (as sample LoginPanel.jar) .

You must see a new Window displayed at your screen .Your JAR file is now Sucessfully Executed !

Congratulation!

Thank you for taking participation on  this blog .

Actually I am going to  show the simple way to merge many jar files to a single jar file .

Requirements:

• Firstly We need the NetBeans6.x.x
• JDK 1.6

Here we’ll create a sample Project which is included in NetBeans.

I ‘m using NetBeans 6.7.1 and now i am starting my demonstration.

Let’s make a project File>New Project> …. and as your requirement you can make a project but there

is need of some extra jar files . If you are not familiar with adding jar files to Projects then ,

Please refer this:

Now you are able to attach jar files in Project.

It’s time time to have some trick now, just choose Files Tab in Project Window or just press Ctrl+2 as shown in figure

File Tab

Now there you will see a build.xml which can be double click to edit it’s source. Now here we can combine our jar files

into single jar file  via XML . Now copy and paste the following text to the end, just before the final line, which is the closing tag</project>

<target name="package-for-store" depends="jar">

      <!-- Change the value of this property to be the name of your JAR,
           minus the .jar extension. It should not have spaces.
           <property name="store.jar.name" value="MyJarName"/>
      -->
      <property name="store.jar.name" value="MarsRoverViewer"/>

      <!-- don't edit below this line -->

      <property name="store.dir" value="store"/>
      <property name="store.jar" value="${store.dir}/${store.jar.name}.jar"/>

      <echo message="Packaging ${application.title} into a single JAR at ${store.jar}"/>

      <delete dir="${store.dir}"/>
      <mkdir dir="${store.dir}"/>

      <jar destfile="${store.dir}/temp_final.jar" filesetmanifest="skip">
          <zipgroupfileset dir="dist" includes="*.jar"/>
          <zipgroupfileset dir="dist/lib" includes="*.jar"/>

          <manifest>
              <attribute name="Main-Class" value="${main.class}"/>
          </manifest>
      </jar>

      <zip destfile="${store.jar}">
          <zipfileset src="${store.dir}/temp_final.jar"
          excludes="META-INF/*.SF, META-INF/*.DSA, META-INF/*.RSA"/>
      </zip>

      <delete file="${store.dir}/temp_final.jar"/>

  </target>

You must see the code like this:

<property name="store.jar.name" value="MarsRoverViewer"/>

XML Format

Ok i’ll explain in brief: On the above code there you will find the line like this:

Here you can edit the code according to your requirements

<property name="store.jar.name" value="MarsRoverViewer"/>

• value=”MarsRoverViewer” defines the filename of the jar which is the combination of all jars.
• property name=”stor.jar.name” define the property ’s name which is stored in a directory /store and the with name of MarsRoverViewer which is defined in attribute value .

After all you have finished your coding phase.

Now, When you’re ready to package all of your classes and libraries into a single JAR file, switch back to the Files view in the upper left, then right-click the build.xml file. Then choose Run Target>Other Targets>package-for-store. Now the compiler will start to combine your class files and other libraries to a single JAR file named MarsRoverViewer.

Executing this Ant target will create a directory called store inside your project directory. NetBeans and Ant will then copy all of the classes and libraries into a temporary JAR file and strip out any unwanted files, placing the final result under the JAR name that you specified earlier. NetBeans will then delete the temporary file.

-Source (http://javacoder.co.cc)

The Java Programming language has it’s operator which is similar to other programming language like C,C++ as well.
All the operator has it’s own rule . So while using these operator we must know how the operators are being compiled by the java
Operator Precedence of Java are given below:

Operator Precedence

Many developers want their own Layout Manager with user-defined so JAVA has provided a separate method for the every container of JFrame Component and that method is setBounds(). This method helps the developers to position the container as per their need .

About SetBounds() method:

This method consists four parameter

  Syntax:
     xxx.setBounds(int x_axis, int y_axis, int width, int height);

We can arrange the containers with the help of this method easily.

A example of this method is shown below:

import javax.swing.*;

public class LoginPanel {

public LoginPanel() {

}

public static void main (String[] args) {
JFrame frame = new JFrame();

frame.setLayout(null);

//For Positioning the Containers

//Labeling
JLabel label = new JLabel("WELCOME TO"+
"LOGIN PANEL", JLabel.CENTER);
JLabel user = new JLabel("UserName:\t");
JLabel pass = new JLabel("Password:\t");

//Some features of SETBOUNDS() Methods
//setBounds(x-axis, y-axis, width, height);
label.setBounds(150,10,220,20);
user.setBounds(150,50,100,50);
pass.setBounds(150,90,100,50);

//TextField
JTextField userField = new JTextField();
JPasswordField passField = new JPasswordField();

//Some of the features of SETBOUNDS() Methods
//setBounds(x-axis, y-axis, width, height);
userField.setBounds(250,65,80,20);
passField.setBounds(250,105,80,20);

//Button
JButton but1 = new JButton("Submit");

//setBounds(x-axis, y-axis, width, height);
but1.setBounds(200,150,100,20);

//adding containers to JFRAME
frame.getContentPane().add(label);
frame.getContentPane().add(user);
frame.getContentPane().add(userField);
frame.getContentPane().add(pass);
frame.getContentPane().add(passField);
frame.getContentPane().add(but1);

//features of JFrame
//Although these can be defined
//before the containers.
//We defined at last
frame.setVisible(true);
frame.setSize(500,300);

}

}

And the output must be like this:

Login Panel Output

JNode is the open-source project for making a Java Platform OS(Operating System).
This project had take a exclusive track of making all the software in Java in itself.
As Java Virtual Machine(JVM) only accepts bytecode so the Compiler used to develop native binaries out. In this way, nearly the entire system is able of being written in the JAVA programming Language.

Ewout Prangsma firstly started work of developing the Java Bootable System(JBS) during 1995 .He had caught special feature of Java. In his mind he himself imagined a system that was not only a VM, but a complete runtime environment that does not need any other form of operating system. So is had to be a light weight and most important flexible system. The author was not satisfied with the C and assembly language required and head towards on to a new attempt called JBS2.

Jnode uses only two languages i.e. Java and Assembly Language. This system presently understands the FAT,NTFS,ext2 and ISO 9660 file system. It also has a GUI(Graphical User Interface) with USB peripherals and TCP/IP network protocol. It can be boot from CD or run in any popular emulator. It uses GNU Classpath Java Library and can run any Java Programs.

The latest version of JNode can be found in :

http://www.jnode.org/download_latest

For more Detail : http://www.jnode.org

If we want to programmatically determine what version of the Java Runtime Environment

(JRE) is being used to execute a given application then, we can get the version via the following code illustrates:

//IN WINDOWS PLATFORM

String ver = System.getProperty("java.version"));
System.out.println("This program is running under JRE version " + ver);

if (ver.startsWith("1.5")) {
// Pseudocode.
do something appropriate for newer versions of Java ...
}

else {
// Pseudocode.
do something the pre-5.0 way ...
}

Some of the java System Properties based on JDK 1.5 are given as follows:

The following table describes some of the most important system properties BASED on JDK 1.6

First of all if you have already java then uninstall that java and download Java Sdk from Sun Microsystem :
For download: jdk 1.6
Then choose your appropriate Operation System and download and Install the *.EXE program

This is one of the tough point for  beginner to install java Beginner.

Some of the steps to maintain Path of Java compiler are given as follows:

STEP 1: Right click on My Computer and Go properties.

STEP 2: Dialogue  Box Appears (given in fig 1.1) Go to Advance Tab > Environment Variables..

Fig 1.1 A Dialogue Box of Advance Tab

STEP 3: Now in New Dialogue box (given in fig.1.2 )  You can click on New Tab for creating new variable

Fig 1.2 Environment Variables Dialogue Box

STEP 4: New Small Dialogue Box appears and there you need to type the variable name as PATH and for Value you      need to paste the \bin directory of Java development kit (jdk 1.x.xx). shown in fig 1.3.

fig 1.3 New User Variable

STEP 5: Now click on Ok and run Command .

STEP 6: In command you need to type javac which output like in fig 1.4

fig. 1.4 javac in command

STEP 7: If your output gives like fig.1.4 then you are able to compile your java source code by following ways

Also I need to tell dat the  we can set CLASSPATH at ENVIRONMENT VARIABLES  via DOS for  compiling java file;

Here are some steps for windows:

> Go to Command Prompt

> type : set JAVA_HOME=directory(path)_of_your_jdk (as on fig 1.5)

fig 1.5

>now type : set CLASSPATH=%JAVA_HOME%\bin.(as on fig 1.6)

fig 1.6

>Also you need to set CLASSPATH of your JAVA LIB(library).

>Type : set CLASSPATH=%JAVA_HOME%\lib (for library of java)

Testing either the compiler path , library is correct or not.

>Type : echo %JAVA_HOME% (displays the path of Java installed)

>Type : echo %CLASSPATH% (displays the path of your java lib, java compiler as well)

If every thing goes alright then compile java file through following ways via Command at DOS:

For eg: To compile HelloWorld.java
Type  : javac HelloWorld.java
Type : java HelloWorld

Outputs:
________________
HelloWorld!!!
________________

That almost Finished in Windows Java Compile !

If any problem occurs then comment me or just mail me!