Java-具有指定类路径的NoClassDefFound错误

Question

When I try to run my jar application, I get a NoClassDefFoundError even though i have referenced the library containing the class in my classpath.

This is the line causing it (in the start method of a thread):

Spark.staticFiles.location("/public");

This defines the location of static files for the Spark framework for java, and I have the spark library in the "lib" folder. The libraries are included in the jar: lib package in the jar

My manifest file looks like this:

Manifest-Version: 1.0

Class-Path: lib/ *

Main-Class: com.xx.xx.xx.Main

This should as far as I know mean that all libraries in lib is included, but if i run the jar with a simple java -jar test.jar i get this:

Exception in thread "Thread-2" java.lang.NoClassDefFoundError: spark/Spark
    at com.xx.xx.xx.Main.run(TundraWebApp.java:20)
    at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.ClassNotFoundException: spark.Spark
    at java.net.URLClassLoader.findClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    ... 2 more

spark/Spark being part of one of the libraries.

Why isn't my libraries detected?

Answer 1

I don't think Class-Path supports wildcards. You'd have to spell out the jar names, eg:

Class-Path: libs/spark-core_2.11-2.3.0.jar libs/spark-sql_2.11-2.3.0.jar