How to create and run runnable jar file of a Java Project.

Question Posted / mkumar_028

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How to create and run runnable jar file of a Java Project...

Answer / jabez

Common Examples
----------------
Let's say I have a Java application consisting of three
source files that I wish to distribute:

One.javaTwo.javaThree.java

I also want to call my JAR file example.jar. To make a JAR
file with just One.java:

jar CF example.jar One.java
To make a file with all three files listed separately:

jar CF example.jar One.java Two.java Three.java
To make a file with all three files using a pattern match:

jar CF example.jar *.java

It goes (almost) without saying that the source files are
in the same directory you are running the jar command in.

------------------------------------------------------------
-----------------

Compress Files To An Executable Java Archive (JAR)
---------------------------------------------------
It is also possible to make an archive that can be executed
(run) by Java and even by a double click through your OS,
if you have it set up correctly. Of course, to do this you
must store compiled class files in the archive, as well as
or instead of Java source files, since Java source files
cannot be run!

Continuing the example above, I now compile my Java source
files:

javac *Java
or

javac One.java Two.java Three.java

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--------------------

Create An Executable JAR
---------------------------
All JAR files contain something called a manifest file
which holds information Java wants to know. One piece of
information a manifest file may contain is the name of a
class that will be run if the JAR file is executed.

The first thing you must do is create a text file that
lists the "main" class - the class that has the main method
you want executed when the JAR is executed. Let's say that
Three from the above example has the main method I want
executed. I create a text file called "mainClass.txt" with
the following text:

Main-Class: Three

IMPORTANT: the text file only needs the one line of text
for this purpose. However, the file must end with a blank
line or this will not work, ie the file has two lines in
it - the second one is empty. Note too the class is
called "Three" and not "Three.java" (the file containing
the source code) or "Three.class" (the file containing the
byte codes). If your class file is in a package hierarchy,
you must use the fully qualified name of the class
(eg "myPackage.MyClass").

I then run the jar utility with this command line:

jar cmf mainClass.txt example.jar *.class
With this line, I told jar to create a JAR file (option c)
with modifications to the manifest file (option m) as
specified within mainClass.txt, naming the JAR file (option
f) as example.jar and including everything that matches the
pattern *Class

------------------------------------------------------------
--------------------

Running An Executable JAR From Command Line
---------------------------------------------
I can run it from the command line like this:

java -jar example.jar

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Running An Executable JAR From Explorer (Windows)
-------------------------------------------------

Within Windows, it is also possible to set up Windows
Explorer so that you can double click on the JAR file icon
to execute the file (handy for GUI applications). The first
thing you must do is set up the correct association with
the 'javaw.exe' application that JDK for Windows will have.
Click here for an older example with pictures! Open Windows
Explorer and select Tools | Folder Options | File Types.

If there is no JAR file type, create it. Give it a
description like

jar - Executable Jar File
to ensure it sorts under 'jar'. Create or edit the action
called "open" and associate it with the following action:

"C:\Java\jdk1.4.0\bin\javaw.exe" -jar "%1"
Of course, you will replace "C:\Java\jdk1.4.0
\bin\javaw.exe" with whatever path is correct on your
machine.

IMPORTANT: include the double quotes to take care of names
with spaces.

If you are using something other than Windows and you know
how to set up an association in your OS, please contact me.

Is This Answer Correct ?

32 Yes

6 No

How to create and run runnable jar file of a Java Project...

Answer / michael gooch

Jabez is correct, but I also think it is wise to note that
most of the newer java installers will set up the JAR
association for double clicking within explorer
automatically.

don't forget to add the java bin folder to your Path
environmental Variable!

Is This Answer Correct ?

6 Yes

3 No

How to create and run runnable jar file of a Java Project...

Answer / r.jude silvester

To crate a Jar file:

Create a manifest file with contents of Main class,created by Jdk version and Manifest-Version

Then use cmd jar cfm <manifest file name> <Jar fileName.jar>
<classnmaes to be included in jar with package name> or <package root/*>

To run Jar

java -jar <Jar fileName.jar>

Is This Answer Correct ?

7 Yes

4 No

How to create and run runnable jar file of a Java Project...

Answer / nitin gupta

yes

Is This Answer Correct ?

8 Yes

11 No

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