nicholas@mordor:~/NetBeansProjects/testng_gradle/app$ 
nicholas@mordor:~/NetBeansProjects/testng_gradle/app$ java -Dtestng.test.classpath="/usr/share/maven-repo/org/testng/testng/debian/testng-debian.jar.org.testng.TestNG testng.xml" src/test/java/testng_gradle/AppTest.java test.xml
src/test/java/testng_gradle/AppTest.java:7: error: package org.testng does not exist
import static org.testng.Assert.*;
                        ^
src/test/java/testng_gradle/AppTest.java:6: error: package org.testng.annotations does not exist
import org.testng.annotations.*;
^
src/test/java/testng_gradle/AppTest.java:10: error: cannot find symbol
    @Test public void appHasAGreeting() {
     ^
  symbol:   class Test
  location: class AppTest
src/test/java/testng_gradle/AppTest.java:11: error: cannot find symbol
        App classUnderTest = new App();
        ^
  symbol:   class App
  location: class AppTest
src/test/java/testng_gradle/AppTest.java:11: error: cannot find symbol
        App classUnderTest = new App();
                                 ^
  symbol:   class App
  location: class AppTest
5 errors
error: compilation failed
nicholas@mordor:~/NetBeansProjects/testng_gradle/app$ 
nicholas@mordor:~/NetBeansProjects/testng_gradle/app$ cat testng.xml 


<test name="Test1">
  <groups>
    <run>
      <include name="functest"/>
    </run>
  </groups>
  <classes>
    <class name="example1.Test1"/>
  </classes>
</test>


nicholas@mordor:~/NetBeansProjects/testng_gradle/app$ 
nicholas@mordor:~/NetBeansProjects/testng_gradle/app$ cat src/test/java/testng_gradle/AppTest.java 
/*
 * This Java source file was generated by the Gradle 'init' task.
 */
package testng_gradle;

import org.testng.annotations.*;
import static org.testng.Assert.*;

public class AppTest {
    @Test public void appHasAGreeting() {
        App classUnderTest = new App();
        assertNotNull(classUnderTest.getGreeting(), "app should have a greeting");
    }
}
nicholas@mordor:~/NetBeansProjects/testng_gradle/app$