for (int i=0; i<100; i++) {
      out.println("Data for " + i + " is " + method1() + " , " + method2() + ".<br>");
  }
  out.close();

  StringBuffer buf = new StringBuffer();
  for (int i=0; i<100; i++) {
      buf.append("Data for ").append(i).append(" is ").append(method1());
      buf.append(" , ").append(method2()).append(".<br>");
  }
  response.setContentLength(buf.length());
  out.println(buf.toString());
  out.close(); 

public void openFile( String fileName ) {
    try {
        someOtherMethodToOpenAFile( fileName );
    } catch( FileNotFoundException e ) {
        out.println( "Sorry... File not found." );
    }
}

/* 'response' variable is an object of the 
   HttpServletResponse class.
*/
public void openFile( String fileName ) {
    try {
        someOtherMethodToOpenAFile( fileName );
    } catch( FileNotFoundException e ) {
        response.sendError( response.SC_NOT_FOUND );
    }
}

<frameset rows="20%,*" cols="80%,*">
    <frame name="Frame1" src="/servlet/someServlet">
    <frame name="Frame2" src="/servlet/anotherServlet">
</frameset>