Jar files

JAR FILES

   JAR stands for Java Archive Page.JAR files allow to deploy set of classes, interfaces and their associated resources.

• -      For creating a game various resources are required such as sound files for e.g.(.mp3), image files for e.g. (.png,jpeg.gif, etc.), a programmer can put all this stuff in a single jar file.
• -      Later this jar file can be deployed to a Bean which controls which file from the deployed file is to be used when.
• -      In addition, there is one more file called as MANIFEST FILE (.mf) is deployed which file in jar are Beans.
• -      Components in a jar files are compressed, hence downloading a jar file is easier and faster than downloading all files separately.
• -      All the games and software majorly on mobile phones and PDAs are deployed using JAR files.

SYNTAX

       jar option file

E.g. for creating a file by name zmn.jar

       jar zmn.jar *.class *.gif

OPTIONS AVAILABLE

c- A new archive is to be created .

C- Changes the directory during command execution.

f- First name in the file list, it is the name of the archive to be created or accessed.

m- Second element in the file list, it is the name of the external manifest file.

M- manifest file not created.

t- archive contents should be tabulated.

u- Updates existing jar file.

v- verbose output should be provided by utilities while it executes.

0-Do not use compression.

x- Files are to be extracted from the archive.

EXAMPLES OF JAR FILES

FOR CREATING A JAR FILE

-      If file az.mft(a manifest file) is present it can be used with following command.

jar cfm zmn.jar az.mft *.class *.gif

FOR DISLAYING THE CONTENT OF JAR FILE

jar tf zmn.jar

 TO EXTRACT THE CONTENT OF A JAR FILE

jar xf zmn.jar

TO UPDATE THE CONTENT OF JAR FILE

jar uvf zmn.jar Add.class

 TO CREATE A JAR FILE WITH SPECIFIC-COMPRESSION

jar cvf zmn.jar D:\\Java\\*.class