[java] Eclipse - Export to JAR + external jar-files
Author
Hi
I have problem exporing my project into a JAR-file in Eclipse.
My project is dependent on "jdom.jar".
I've added this jar-file into the build path of the project ("Project -> Properties -> Libraries").
My JAR file contains jdom.jar, but the "manifest.mf" does not contain an entry
for "jdom.jar".
So when I try to execute my jar file it says:
"Exception in thread "main" java.lang.NoClassDefFoundError: org/jdom/Content"
How do I solve this?
Why doesn't Eclipse import the classpath to "jdom.jar" into the manifest file?
(jdom.jar is in the root of my jar file).
Kind Regards
I don't think you can get Eclipse to include a class-path when exporting your jar. It wouldn't make much sense anyway, since the paths to the jars wouldn't make sense outside of your development environment.
Also please note that it is not possible to include jars within jars.
What you could do is write an Ant build script and have Eclipse run it. In the script, copy all jars to a destination folder, and run a jar task to compile your jar and place it in the destination folder, with a relevant classpath entry.
You need to write something like this (taken partly from one of my projects):
If you want to put everything into one jar nevertheless, you will have to unpack the other jar and pack everything together into one jar. A jar is for the most part just a glorified zip file so you can use winzip to do this.
Also please note that it is not possible to include jars within jars.
What you could do is write an Ant build script and have Eclipse run it. In the script, copy all jars to a destination folder, and run a jar task to compile your jar and place it in the destination folder, with a relevant classpath entry.
You need to write something like this (taken partly from one of my projects):
<project name="engine" default="make" basedir="f:/projects/code"> <description> Ant targets for Engine </description><property name="jars" location="../data/jars/" /><property name="dist" location="../dist/engine/" /><property name="engine-bin" location="/engine/bin/" /><target name="make" description="make the engine"><copy todir="${dist}"> <fileset dir="${jars}"/></copy> <jar jarfile="${dist}/engine.jar" basedir="${engine-bin}"> <manifest> <attribute name="Class-Path" value="lwjgl.jar lwjgl_devil.jar lwjgl_test.jar lwjgl_util.jar dom4j-1.6.1.jar mantissa-6.3.jar jarmor-1.0.jar bsh-2.0b4.jar"/> <attribute name="Built-By" value="${user.name}"/> <attribute name="Main-Class" value="com.engine.util.Stub"/> </manifest></jar></target></project>If you want to put everything into one jar nevertheless, you will have to unpack the other jar and pack everything together into one jar. A jar is for the most part just a glorified zip file so you can use winzip to do this.
Author
Hi lightbringer
Thanks for answering!
What about if I have my external jars outside my jar file?
Then I have my jar (myjar.jar) and my external jar (jdom.jar).
I then write:
java -jar -classpath "jdom.jar;." myjar.jar
And I still get the error:
"Exception in thread "main" java.lang.NoClassDefFoundError: org/jdom/Content"
What Im I doing wrong?
Kind Regards
Thanks for answering!
What about if I have my external jars outside my jar file?
Then I have my jar (myjar.jar) and my external jar (jdom.jar).
I then write:
java -jar -classpath "jdom.jar;." myjar.jar
And I still get the error:
"Exception in thread "main" java.lang.NoClassDefFoundError: org/jdom/Content"
What Im I doing wrong?
Kind Regards
You can't use -classpath and -jar options at the same time. If you specify a -jar option, then you have to include the necessary libraries in the jar's manifest.mf file.
Author
Thanks!
I now added this to my manifest file:
"Class-Path: jdom.jar ."
It works!
But now to another problem.
My images can't be found!
I access all my images by:
return new ImageIcon("Resources/image.png").getImage();
If I move the "Resource" directory outside the jar-file, it works.
But why cant the pictures be found if the "Resource" directory is
within the jar file?
("Resource" is one of the root directories)
Kind Regards
I now added this to my manifest file:
"Class-Path: jdom.jar ."
It works!
But now to another problem.
My images can't be found!
I access all my images by:
return new ImageIcon("Resources/image.png").getImage();
If I move the "Resource" directory outside the jar-file, it works.
But why cant the pictures be found if the "Resource" directory is
within the jar file?
("Resource" is one of the root directories)
Kind Regards
You have to be a bit creative. To get at your resources within the jar, for ImageIcon, try passing the string "jar:file://" + System.getProperty("user.dir") + "/yourprog.jar!/path/to/Resources/image.png"
Alternatively, and this is a bit simpler and more reliable, you could try passing this URL to ImageIcon: this.getClass().getResource("/Resources/image.png")
Alternatively, and this is a bit simpler and more reliable, you could try passing this URL to ImageIcon: this.getClass().getResource("/Resources/image.png")
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