使用Eclipse导出带有外部库的Java Project

Question

i'm trying to export my Java Project into a runnable JAR file with eclipse but if i want to run the finished JAR file I always get the error

Java Virtual Machine Launcher

Could not find the main class: src.main. Program will exit.

src.main is my main class, if i open the jar with winrar this class is in the folder src in the jar file.

I export the Project like this:

• Right click on the Project name
• Export
• Runnable JAR file -> Next
• Launchconfig: my main class.
• destination: ...\\Desktop\\asdf.jar
• Library handling: Extract required libraries into generated JAR (I also tried all the others)
• Finish
• I get a Warning: "JAR export finished with warnings. .."
• OK

The libraries are added like this:

• Right click on the Project name
• Properties
• Java Build Path
• Libraries
• Add External JARs
• And than all the libraries are together in one external folder.

What am I doing wrong?

Answer 1

Does src.Start have a proper "public static void main(String[] args)" method?

Are you trying to start the app like this:

"java -jar myjar.jar" or "java -cp myjar.jar src.start"

Also, are you building the manifest by hand, or letting eclipse do it? I don't remember ever seeing eclipse add a classpath entry in the manifest but I might have missed it.

On the "Jar Manifest Specification" panel during the export, just select "generate the manifest file" and fill in the "Main class:" entry in the input field.

Answer 2

The first thing that I recommend you: don't use src.main in the way that you are doing it right now. In Java usually we use a folder called src or src/main or src/main/java to put the sources. Then, to use this as a package and class name is not a good idea. Secondly; don't call your class main it is not a keyword in Java, you can create a class with this name but... it's not a good idea.

And the solution to your problem: you need to set up your Main-Class and your Class-Path in your manifest file and be sure about the structure of your package (your jar), take a look into this tutorial , it will help you.