jar file

 

The most common command to make a new jar file users the following syntax:

Jar cvf JARFileName File1 File2...

Jar cvfm jarname manifest.mf class1 class2

The option:

-c  create new archive file

-t  list archive file

-x  Extract the archived specified (or all) files

-u  update an existing jar file

-v  In the standard output to generate verbose output

-f  Specify the archive file name

-m  The list of files that contain a specified list of information

-e  Bundled into the executable jar file for the separate applications

     Specify the application entry point

-0  Only storage; do not use any ZIP compression

-M  Does not create entries in the list of documents

-i  generate index info for Specify a jar file

-C  update to specify dictionary and content it file

The Manifest:

Is called MANIFEST.MF and is located in a special META-INF subdirectory of the jar file

The minimum legal manifest is quite boring –just   Manifest-Version: 1.0

 

Complex manifests can have many more entries. The manifest entries are grouped into sections . the first ection in the manifest is calld the main section. It applies to the whole JAR fiile .Subsequent entries can specify properties of named entites such as in dividual  files ,package ,or URLs. Those entries must begin with  a Name entry.Seciton are separated by blank lines.For example:

     Manifest-Version: 1.0

Lines describing this archive

 

Name:Woozle.class

Lines describing this file

Sealing

       The manifest like this:

       Name: aken/xml/

       Sealed: true

      

       Name: aken1/xml/

       Sealed: false

Packaging Beans in JAR Files

Pattern:

Manifest-Version: 1.0

 

Name: com/horstmann/corejava/ImageViewerBean.class

Java-Bean: True

 

We place our example beans into the package com.horstmann.corejava because some builder environments have problems loading beans from the default package.

If your bean contains multiple class files, you just mention in the manifest those class files that are beans and that you want to have displayed in the toolbox. For example, you could place ImageViewerBean and FileNameBean into the same JAR file and use the manifest

Manifest-Version: 1.0

Name: com/horstmann/corejava/ImageViewerBean.class

Java-Bean: True

Name: com/horstmann/corejava/FileNameBean.class

Java-Bean: True

Make sure that there are no spaces after the ends of each line, that there are blank lines after the version and between bean entries, and that the last line ends in a newline.