[Java] How to pass JVM options from bootRun


Answers

bootRun {
  // support passing -Dsystem.property=value to bootRun task
  systemProperties = System.properties
}

This should pass all JVM options to the app started via bootRun.

Question

I'm developing simple Spring web application that communicates with remote host and I would like to test it locally behind corporate proxy. I use "Spring Boot" gradle plugin and the question is how can I specify proxy settings for JVM?

I have try several ways to do it:

  1. gradle -Dhttp.proxyHost=X.X.X.X -Dhttp.proxyPort=8080 bootRun
  2. export JAVA_OPTS="-Dhttp.proxyHost=X.X.X.X -Dhttp.proxyPort=8080"
  3. export GRADLE_OPTS="-Dhttp.proxyHost=X.X.X.X -Dhttp.proxyPort=8080"

But it seems like none of them work - "NoRouteToHostException" throws in "network" code. Also, I have added some extra code to debug JVM start arguments:

    RuntimeMXBean runtimeMxBean = ManagementFactory.getRuntimeMXBean();
    List<String> arguments = runtimeMxBean.getInputArguments();
    for (String arg: arguments) System.out.println(arg);

And only one argument was printed: "-Dfile.encoding=UTF-8".

If I set system property in code:

    System.setProperty("http.proxyHost", "X.X.X.X");
    System.setProperty("http.proxyPort", "8080");

Everything works just fine!




I had to add this:

bootRun {
    String activeProfile =  System.properties['spring.profiles.active']
    String confLoc = System.properties['spring.config.location']
    systemProperty "spring.profiles.active", activeProfile
    systemProperty "spring.config.location", "file:$confLoc"
}

And now bootRun picks up the profile and config locations.

Thanks a lot @jst for the pointer.




Passing JVM args to SpringBoot bootRun Gradle task

Got it working by using jvmArgs, as detailed in this SO question [ How to pass JVM options from bootRun ]

bootRun {
    jvmArgs = ["-Xbootclasspath/p:<fully-qualified-path-to-jar>"]
}



Problems passing system properties and parameters when running Java class via Gradle

Figured it out. The main issue is that when Gradle forks a new Java process, it does not automatically pass the environment variable values along to the new environment. One has to explicitly pass these variables via the systemProperties property of the task or plugin.

The other issue was understanding how to pass command-line args; these are via the args property on the task or plugin. As with the Maven exec-maven-plugin, they should be passed in on the command line via yet another system property, as a space-delimited list that then needs to be split() before setting args, which accepts List objects. I've named the property exec.args, which is the old Maven name.

It seems both the javaExec and application plugin approach are valid. One might favor the application plugin approach if one wants to use some of its other features (automatically putting together a distribution, etc.)

Here are the solutions:

JavaExec Approach

Command Line:

gradle execute -Dmyvariable=myvalue -Dexec.args="arg1 arg2 arg3"

build.gradle:

task execute (type:JavaExec) {

    main = "com.myCompany.MyMain"
    classpath = sourceSets.main.runtimeClasspath 

    /* Can pass all the properties: */
    systemProperties System.getProperties()

    /* Or just each by name: */
    systemProperty "myvariable", System.getProperty("myvariable")

    /* Need to split the space-delimited value in the exec.args */
    args System.getProperty("exec.args", "").split()    
}

Application Plugin Approach

Command Line:

gradle run -Dmyvariable=myvalue -Dexec.args="arg1 arg2 arg3"

build.gradle:

apply plugin: 'application'
mainClassName = "com.mycompany.MyMain"
run {    
    /* Can pass all the properties: */
    systemProperties System.getProperties()

    /* Or just each by name: */
    systemProperty "myvariable", System.getProperty("myvariable")

    /* Need to split the space-delimited value in the exec.args */
    args System.getProperty("exec.args", "").split()    
}