title: java - get text from JTextArea by number line
body: <p>For my case, I want to get text inside JTextArea by number line.</p>
  
  <p>For e.g</p>
  
  <pre><code>name : andy
  birth : jakarta, 1 jan 1990
  number id : 01011990 01
  age : 26
  study : Informatics engineering
  </code></pre>
  
  <p>So, I want to get a text in line 3.</p>
  
  <p>I think I can use <code>jTextArea.getText(3,jTextArea.getText().length())</code>,
  but it doesn't work.</p>
  
  <p>so, from line 3, i wish get text</p>
  
  <pre><code>number id : 01011990 01
  </code></pre>