如何验证我的MAVEN_OPTS环境变量是否正在传递给正在启动的java进程？

Question

I'm setting some options -Dmyflag=myvalue in MAVEN_OPTS. I know this works based on other testing I've done (when using mvn spring-boot:run ) but a newly set value I'm using doesn't seem to be working.

The first place to start is to make sure the option is being passed to the program being started by maven. In my case, I'm running a unit test that dsdsneeds some options set on the command line.

Is there a maven command that will show me the -Doptions that are being passed to the java commands that are started by Maven?

NOTE: This may be an issue with the surefire plugin not passing MAVEN_OPTS when starting tests.

I've tried

mvn -X clean install

and I see output that implies that a test is being started, the output is something like:

Forking command line: /bin/sh -c cd /my/proj && /usr/bin/java -jar /.../my.jar

And I don't see any options being passed so I'm guessing that the MAVEN_OPTS are not being passed to the unit test that is running.

Searching for answers I found these links:

• How to pass parameter to maven test

• Passing properties to surefire plugin (Not on StackOverflow).

• Passing command line arguments to surefire plugin (Not on StackOverflow).

Answer 1

From mvn --help :

-D,--define Define a system property

So anything you pass in with -D , you should be able to read back with System.getProperty("<arg>") .

Alternatively, you can use mvn -X ... to see what is being passed:

-X,--debug Produce execution debug output

As for your comment:

This may be an issue with the surefire plugin not passing MAVEN_OPTS when starting tests.

From my own experiments, and I wish I had a citation for this, when tests are run - either with surefire or failsafe - they are run in a separate thread. This new thread does not receive any properties from MAVEN_OPTS. However, it will receive properties passed on the command line with -D...