title: Add another java source directory to gradle script
body: <p>I hava an example java project package </p>
  
  <p>package com.example.testing;</p>
  
  <p>with such file tree</p>
  
  <pre><code>app
  |
    src-&gt;com-&gt;example-&gt;testing-&gt;Main.java
  </code></pre>
  
  <p>and a gradle script:</p>
  
  <pre><code>apply plugin: 'java'
  apply plugin: 'application'
  
  sourceSets {
      main {
          java {
              srcDirs 'src'
          }
      }
  
  
  }
  
  sourceSets.main.output.classesDir = file("classes")
  mainClassName = 'com.example.testing.Main'
  
  defaultTasks 'compileJava', 'run'
  </code></pre>
  
  <p>Now I want to add some module to this project and my folders will be something like this</p>
  
  <pre><code>app
  |
    src1-&gt;com-&gt;example-&gt;testing-&gt;Main.java
  
    src2-&gt;com-&gt;another_example-&gt;another_testing-&gt;Library.java
  </code></pre>
  
  <p>How do I add new source code to gradle script?</p>