java: using external library

Question

Hello,

I would like to use an external library (e.g. google's guava) for my java program. I use eclipse IDE, so I downloaded guava's jar (and sourced) and followed http://www.vogella.de/articles/Eclipse/article.html#classpath_jar to add it to eclipse and to the builpath of my project. This works fine: I can run the program from eclipse and from the runnable jar I export from eclipse, but I get an error when I try to run directly from the bin/ dir, as I used to do before:

Exception in thread "main" java.lang.NoClassDefFoundError: com/google/common/base/Joiner

What should I do?

thanks, Dave

Answer 1

If you're running the class file directly from the project bin directory then you may have to specify the classpath manually: C:> java -classpath C:\java\MyClasses;C:\java\OtherClasses MyClassHere

Answer 2

To run the program on console as precise as possible with when you run it from Eclipse, you need to run it from the root directory of the project (not from bin) and don't forget to mention the classpath (http://download.oracle.com/docs/cd/E17476_01/javase/1.5.0/docs/tooldocs/windows/classpath.html)

So for example on root you will run:

java -classpath lib/guava.jar;bin packageName.className

Answer 3

Have you tried java -cp guava.jar ... ?

Answer 4

Youll have to tell Java where to find the library:

java -cp <path-to-lib-jar>;myJar.jar my.package.MyMainClass

or if you wanna use a jar file you can set the library path in the MANIFEST check here for an explanation.