I've compiled a JAR file and specified the Main-Class in the manifest (I used the Eclipse Export function). My dependencies are all in a directory labeled lib
. I can't seem to get a straight answer on how to execute my JAR file while specifying it should use the lib/*
as the classpath.
I've tried:
]$ java -jar -cp .:lib/* MyJar.jar
]$ java -cp .:lib/* -jar MyJar.jar
]$ java -cp .:lib/* com.somepackage.subpackage.Main
etc...
Each gives an error saying:
Error: Could not find or load main class ....
or gives the NoClassDefFoundError
indicating the libraries are not being found.
I even tried remaking the JAR file and included the lib
directory and contents, but still no dice...
How can I execute a JAR file from the command line and specify the classpath to use?
This question is related to
java
shell
command-line
classpath
Alternatively, use the manifest to specify the class-path and main-class if you like, so then you don't need to use -cp
or specify the main class. In your case it would contain lines like this:
Main-Class: com.test.App
Class-Path: lib/one.jar lib/two.jar
Unfortunately you need to spell out each jar in the manifest (not a biggie as you only do once, and you can use a script to build the file or use a build tool like ANT or Maven or Gradle). And the reference has to be a relative or absolute directory to where you run the java -jar MyJar.jar
.
Then execute it with
java -jar MyJar.jar
You can do these in unix shell:
java -cp MyJar.jar:lib/* com.somepackage.subpackage.Main
You can do these in windows powershell:
java -cp "MyJar.jar;lib\*" com.somepackage.subpackage.Main
You can do a Runtime.getRuntime.exec(command) to relaunch the jar including classpath with args.
Run a jar file and specify a class path like this:
java -cp <jar_name.jar:libs/*> com.test.App
jar_name.jar
is the full name of the JAR you want to execute
libs/*
is a path to your dependency JARs
com.test.App
is the fully qualified name of the class from the JAR that has the main(String[])
method
The jar and dependent jar should have execute permissions.
Source: Stackoverflow.com