title: How to grep a String in all the java files in subdirectories?
body: <p>I want to use <code>grep</code> to find the lines contain <code>String</code> in all java files under current directory.</p>
  
  <p>I tried:</p>
  
  <pre><code>grep -r "String" **/*.java
  </code></pre>
  
  <p>But it doesn't work:</p>
  
  <pre><code>grep : **/*.java:  no such file or directory
  </code></pre>
  
  <p>How to write it?</p>
  
  <hr>
  
  <p><strong>UPDATE</strong></p>
  
  <p>I'm on windows, using the <code>grep</code> provided by <code>unxUtils</code>, which doesn't support <code>--include</code> parameter. Is there any other way?</p>