Easiest Way to Merge a Release into One Jar File

Easiest way to merge a release into one JAR file

Eclipse 3.4 JDT's Runnable JAR export wizard.

In Eclipse 3.5, this has been extended. Now you can chose how you want to treat your referenced JAR files.

Merging Multiple Jars in to a Single Jar

In the past, there were JARs with weird content (like the DB2 driver which contains com.ibm and com.IBM; after decompressing in a Windows filesystem, those two packages would be merged).

The only issue you need to be aware of are signed jars and other files in META-INF which might have the same name in multiple source JARs.

A simple solution for all these issues is to use One-JAR. It allows to wrap several JARs into one without unpacking them, first. And read this answer: Easiest way to merge a release into one JAR file

How to Combine Multiple Jars into One?

First of all, let me say that there really is no reason to combine the jars - you can deploy an applet using your class file (not in a jar) and its separate dependent jars.

However, if you feel that you must make one big jar out of your class and all of its dependencies, then you can do so.

You can't put jar files into another jar file, however - jar files don't work that way.
What you need is for all of the contents of all of the jar files to be extracted, and then zipped up again into one jar.

If you're going to do this, I would suggest using the Maven build tool to do it.
Once you set up your build with Maven, you can configure the Maven Assembly Plugin to build one big jar for you.

I know that Eclipse supports Maven, and I assume that NetBeans does as well.

Can i combine many jar files in one jar file

Your may want to have a look at jarjar.

If you use an ant task you can also go for zipgroupfileset:

<zip destfile="jarlibrary.jar">
    <zipgroupfileset dir="lib" includes="*.jar"/>
</zip>

Can i combine many jar files in one jar file

Your may want to have a look at jarjar.

If you use an ant task you can also go for zipgroupfileset:

<zip destfile="jarlibrary.jar">
    <zipgroupfileset dir="lib" includes="*.jar"/>
</zip>

Combining multiple .java files into one .jar file (they are dependent of each other) in Eclipse

Simply, you can export them.

In the package explorer, select all of the necessary java files wit Ctrl+click, right-click the selection, and select "export"

Continue through the wizard, selecting Runnable Jar file or Jar File to your liking, select the export directory, and finish. You are done.

However, if you selected to export the ant buildfile, you can reuse it with a builder. Right-click your project, and select properties.

Under "builders", add a new builder as shown here:

Its type should be an ANT builder.

For the buildfile, select browse workspace or browse filesystem(depending on where you exported it) and select the .xml file you exported previously. You can now do Project->Build and your Ant build will occur as part of the build process.

Creating a merged executable Jar from many jar files(used in classpath)

You could specify a path to each at file in the manifest

Class-Path: lib/poi-3.7-20101029 ...

And store the library jars here.

While I like the idea of combining all he classes into a single Jar, you need to be careful of resources that might share the same path. We have this issue in our app, all our Jars contain a Version file we use as a marker and read via Class.getResources(...)

---

Related Topics