pass a java parameter from maven

Question

I need to execute some tests with maven, and pass a parameter from the command line.

My java code should get the parameter as: System.getenv(\"my_parameter1\");

Answer 1

The maven surefire plugin also has an option to set environment variables, just add this to your plugin configuration.

<environmentVariables>
    <my_parameter1>value</my_parameter1>
</environmentVariables>

I think this requires that the plugin operates in fork mode, which is the default.

Answer 2

Use

${env.my_parameter} 

to access the environment variable in the pom.xml.

You can use the help plugin to see which variables are set with

mvn help:system

However the normal properties usage should work too. In the large context however I am wondering... what do you want to do? There might be a simpler solution.

Answer 3

System.getenv() reads environment variables, such as PATH. What you want is to read a system property instead. The -D[system property name]=[value] is for system properties, not environment variables.

You have two options:

1. If you want to use environment variables, use the OS-specific method of setting the environment variable my_parameter1 before you launch Maven. In Windows, use set my_parameter1=<value>, in 'nix use export my_parameter1=<value>.

2. You can use System.getProperty() to read the system property value from within your code.

example:

String param = System.getProperty("my_parameter1");

In you surefire plugin configuration, you can use:

<configuration>
    <systemPropertyVariables>
        <my_property1>${my_property1}</my_property1>
    </systemPropertyVariables>
</configuration>

Which takes the Maven property _my_property1_ and sets it also in your tests.

More details about this here.

I'm not sure if system properties from Maven are automatically passed to tests and/or whether fork mode affects whether this happens, so it's probably a good idea to pass them in explicitly.