title: java DataOutputStream getOutputStream() getInputStream()
body: <p>one question</p>
  
  <p>in the case for example of </p>
  
  <pre><code>DataOutputStream output= new DataOutputStream(clientSocket.getOutputStream()) ;
  </code></pre>
  
  <p>or </p>
  
  <pre><code>DataInputStream in = new   DataInputStream(clientSocket.getInputStream());
  </code></pre>
  
  <p>must these objects to be created each time i need an I/O operation  or just invoke a read or a write on them each time i need??? ( plus some flushing after each operaration) </p>