title: Add byte array to another byte array at specific position java
body: <p>I want to create a byte array of size 512 bytes. </p>
  
  <p>For the first 100 bytes I want to reserve it for filename, for the next 412 bytes I want to use it to store data from the file itself. </p>
  
  <p>Something like this :</p>
  
  <p>|----100byte for file name ----||------------412 byte for file data------------|</p>
  
  <pre><code>      byte[] buffer = new byte[512];
        add the filename of  byte[] type into the first 100 position
        insert the file data after the first 100 position 
  </code></pre>
  
  <p>The file name can be less than 100 bytes.</p>
  
  <p>But I am unable to append the file data at the specific position... how should I do that?</p>