How do I call a static Java method from Gradle

Question

I have a gradle build script which currently works by simply executing a Java class through it's main method. What I want to know is, how can I call a static method in the same class but not have to go through the main method. The current gradle code is as follows:

import org.apache.tools.ant.taskdefs.condition.Os
apply plugin: 'java'

defaultTasks 'runSimple'

project.ext.set("artifactId", "test-java")

File rootDir = project.getProjectDir()
File targetDir = file("${rootDir}/target")
FileCollection javaClasspath = files("${targetDir}/tools.jar")

task(runSimple, dependsOn: 'classes', type: JavaExec) {
    main = 'com.test.model.JavaTest'
    classpath = javaClasspath
    args 'arg1'
    args 'arg2'
}

And my Java class as follows:

package com.test.model;

public class JavaTest {

    public static void main(String[] args) throws Exception {
        System.out.println("In main");
        anotherMethod(args[0], args[1]);
    }

    public static void anotherMethod(String arg1, String arg2) {
        System.out.println("In anotherMethod");
        System.out.println(arg1 + " " + arg2);
    }
}

This gives me the output:

:compileJava UP-TO-DATE
:processResources UP-TO-DATE
:classes UP-TO-DATE
:runSimple
In main
In anotherMethod
arg1 arg2

BUILD SUCCESSFUL

Total time: 2.344 secs

My question is simply how can I skip the main method, and call the method "anotherMethod" directly from the gradle script? The output would then simply be:

In anotherMethod
arg1 arg2

Thanks

Answer 1

you have to add the jar or class to the classpath. here is an example with a jar file who contains the class. Inside the file build.gradle add the dependencies. My jar file is in the lib folder the path is lib/MQMonitor.jar.

import mypackage.MyClass
buildscript {
   repositories {
      flatDir name: 'localRepository', dirs: 'lib'
   }
    dependencies {
        classpath name: 'MQMonitor'
    }
}

task myTaskCallJava << {
   MyClass.foo()
}

Answer 2

Assuming the class is on the buildscript classpath (it should be, since you're calling main from the same class)

task runSimple {
  doLast {
    com.test.model.JavaTest.anotherMethod("foo", "bar")
  }
}

Tested on Gradle 4.6