Reference jars inside a jar

by

You will need a custom class loader for this, have a look at One Jar.

One-JAR lets you package a Java application together with its dependency Jars into a single executable Jar file.

It has an ant task which can simplify the building of it as well.

REFERENCE (from background)

Most developers reasonably assume that putting a dependency Jar file into their own Jar file, and adding a Class-Path attribute to the META-INF/MANIFEST will do the trick:


jarname.jar
| /META-INF
| |  MANIFEST.MF
| |    Main-Class: com.mydomain.mypackage.Main
| |    Class-Path: commons-logging.jar
| /com/mydomain/mypackage
| |  Main.class
| commons-logging.jar

Unfortunately this is does not work. The Java Launcher$AppClassLoader does not know how to load classes from a Jar inside a Jar with this kind of Class-Path. Trying to use jar:file:jarname.jar!/commons-logging.jar also leads down a dead-end. This approach will only work if you install (i.e. scatter) the supporting Jar files into the directory where the jarname.jar file is installed.

More Related Contents:

  1. How to get the path of a running JAR file?
  2. Can’t execute jar- file: “no main manifest attribute”
  3. How to make an executable JAR file?
  4. Running JAR file on Windows
  5. “Invalid signature file” when attempting to run a .jar
  6. Execute another jar in a Java program
  7. What causes “Unable to access jarfile” error?
  8. Creating runnable JAR with Gradle
  9. Why is my URI not hierarchical? [duplicate]
  10. Execute .jar file from a Java program
  11. How do I read the manifest file for a webapp running in apache tomcat?
  12. Visual Studio Code, Java Extension, how to add a JAR to classpath?
  13. NoClassDefFoundError while trying to run my jar with java.exe -jar…what’s wrong?
  14. Java command line with external .jar
  15. Creating Runnable Jar with external files included
  16. Why has it failed to load main-class manifest attribute from a JAR file?
  17. Can values defined in MANIFEST.MF be accessed programmatically?
  18. “Could not find the main class” error when running jar exported by Eclipse
  19. Producing executable jar in NetBeans
  20. How to run a class from Jar which is not the Main-Class in its Manifest file
  21. Double Clicking JAR file does not open Command Prompt
  22. How to use a file in a jar as javax.net.ssl.keystore?
  23. Run a jar File from java program
  24. How to copy files out of the currently running jar
  25. Why does my JAR file execute at CMD, but not on double-click?
  26. What is the maven-shade-plugin used for, and why would you want to relocate Java packages?
  27. Including jar files in class path
  28. Accessing a file inside a .jar file [duplicate]
  29. Convert .Jar to .Dmg
  30. How to create my own java library(API)?

Leave a Comment