Maven: How to run a .java file from command line passing arguments

93
votes

I have the following problem. I would like to run mvn from command line for a Main.java file. Main.java accepts a parameter. How do I do that from command line?

I tried finding an example but I was not successful. Could someone help me by giving me an example of that?

I looked here but didn't quite understand what I should do.

Also, how do I execute that command from a different folder than the Main.java folder?

for example the Main.java is located in my/java/program/Main.java. What should I put in

mvn exec:java -Dexec.mainClass="what to put here?" -Dexec.args="arg0 arg1 arg2"
3
javamavenarguments
What exactly did you not understand from the linked tutorial? Its pretty straight-forward. Please add to your question, the code you have tried so far. - Perception
Basically what I am trying to do is to call a java class from another java class. Normally I run that class from Eclipse. I am using Runtime.getRuntime().exec(""); to execute that class from another java program. But Main.class needs mvn to run. (I edited the question) - phedon rousou

3 Answers

159
votes

You could run: mvn exec:exec -Dexec.args="arg1".

This will pass the argument arg1 to your program.

You should specify the main class fully qualified, for example, a Main.java that is in a package test would need

mvn exec:java  -Dexec.mainClass=test.Main

By using the -f parameter, as decribed here, you can also run it from other directories.

mvn exec:java -Dexec.mainClass=test.Main -f folder/pom.xm

For multiple arguments, simply separate them with a space as you would at the command line.

mvn exec:java -Dexec.mainClass=test.Main -Dexec.args="arg1 arg2 arg3"

For arguments separated with a space, you can group using 'argument separated with space' inside the quotation marks.

mvn exec:java -Dexec.mainClass=test.Main -Dexec.args="'argument separated with space' 'another one'"
8
votes

Adding a shell script e.g. run.sh makes it much more easier:

#!/usr/bin/env bash
export JAVA_PROGRAM_ARGS=`echo "$@"`
mvn exec:java -Dexec.mainClass="test.Main" -Dexec.args="$JAVA_PROGRAM_ARGS"

Then you are able to execute:

./run.sh arg1 arg2 arg3
7
votes

In addition to running it with mvn exec:java, you can also run it with mvn exec:exec

mvn exec:exec -Dexec.executable="java" -Dexec.args="-classpath %classpath your.package.MainClass"