运行已构建的jar时发生ClassNotFoundException

Question

I added the jar for com.drew.* which is :-

metadata-extractor-2.4.0-beta-1.jar

I am also able to build my application in Eclipse without any error. But when I run my application's jar (that includes all the required jars including the above one), I get the following error:

Error: java.lang.ClassNotFoundException: com.drew.imaging.jpeg.JpegMetadataReader

Any suggestions?

Thanks in advance..

Answer 1

Open executable jar (using 7z / WinRAR , etc.) and look if there is your metadata-extractor jar included - also open your Manifest and see if this jar is in the classpath.

In case everything above is fine I think there is probably jar dependency version mismatch.

Do you exporting your executable jar using Eclipse File->Export->Runnable JAR file? It should work just as in the Eclipse

Answer 2

You need to provide the classpath in MANIFEST.MF file. You can view this file using any extractor tool. If dependent jar is in folder than provide the folder name in classpath Entry should look like

  Class-Path: folder/jarfilename

This will help you further http://docs.oracle.com/javase/tutorial/deployment/jar/downman.html

Answer 3

It looks like with eclipse when building a jar you have to choose which resources you would like to be included . Maybe you did not select that jar?