How to execute a java program with external jar

Question

I want to run my program with guava. If I compile my program with

EDIT: java -> javac for the compile call

javac -cp myPackages/guava-13.0.jar MyScanner.java

there is no problem.

If I try to run

java MyScanner -cp myPackages/guava-13.0.jar

I get this output on the console:

Exception in thread "main" java.lang.NoClassDefFoundError: com/google/common/base/Optional
at MyScanner.main(MyScanner.java:37)
Caused by: java.lang.ClassNotFoundException: com.google.common.base.Optional
at java.net.URLClassLoader$1.run(URLClassLoader.java:217)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:205)
at java.lang.ClassLoader.loadClass(ClassLoader.java:321)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:294)
at java.lang.ClassLoader.loadClass(ClassLoader.java:266)
... 1 more

Can you tell me how I can execute the program with the external jar?

Can you show your jar file's manifest file? Does it include a class-path statement directed to the guava jar files? — Hovercraft Full Of Eels
– Hovercraft Full Of Eels, Commented Aug 8, 2012 at 16:58

Amir Afghani · Accepted Answer · 2012-08-08 17:05:31Z

5

I think what you want is:

java -cp myPackages/guava-13.0.jar:. MyScanner

Notice I'm setting two values in the classpath, '.' (current directory) and the path to guava. Your problem is that you specified the classpath option after you specified your main class MyScanner. Options that are specified after your main class are arguments to your program, not to java itself.

answered Aug 8, 2012 at 17:05

Amir Afghani

38.7k17 gold badges87 silver badges128 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

lennykey Over a year ago

Thank you very much :-) That was exactly what I needed to run my program. Now I don't get more ClassNotFound Problems

Amir Afghani Over a year ago

No problem. Typically on SO - we accept an answer that helped us solve the problem. You can do so by clicking the check box next to the answer you felt addressed your issue best.

Bhavik Ambani · Accepted Answer · 2012-08-08 16:59:22Z

1

You should try the below thing

java -classpath myJar.jar my.package.Program

answered Aug 8, 2012 at 16:59

Bhavik Ambani

6,66515 gold badges58 silver badges87 bronze badges

Comments

John Smith · Accepted Answer · 2012-08-08 17:15:50Z

1

Because anything after your classes name

java MyScanner -whatever is --after
               ^         ^  ^

will be arguments to the main method in your class and everything before your class name

java --what -is -before MyScanner
     ^      ^   ^

will be arguments for the jvm. -cp or -classpath must be a jvm argument not an argument for your program.

It must read

java -cp myPackages/guava-13.0.jar MyScanner

edited Aug 8, 2012 at 17:15

answered Aug 8, 2012 at 17:05

John Smith

2,3321 gold badge15 silver badges23 bronze badges

1 Comment

lennykey Over a year ago

If I try this I get: Exception in thread "main" java.lang.NoClassDefFoundError: MyScanner

Collectives™ on Stack Overflow

How to execute a java program with external jar

3 Answers 3

2 Comments

Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

2 Comments

Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related