title: How to run a JUnit Test in android studio?
body: <p>i think tests in the instruementTest  should relevant to android, so need i add an addtional source folder such as src/test/java？
  it looking that the testfile in  src/test/java didn't compiled.</p>
  
  <p>how can i run a junit test independently?</p>
  
  <p>how can i run the junit test only in a command line, no the instrumentTest about android?</p>
  
  <p><img src="https://i.stack.imgur.com/Y5YOf.png" alt="enter image description here"></p>
  
  <p><img src="https://i.stack.imgur.com/Taprv.png" alt="enter image description here"></p>
  
  <p>or 
  put and junit test in the instruementTest folder and call </p>
  
  <pre><code>     ./gradlew connectedInstrumentTest
  </code></pre>
  
  <p>but,the unit test won't run at all.</p>