package moreservlets.filters;

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;


/** A response wrapper that takes everything the client
 *  would normally output and saves it in one big
 *  character array. 
 *  <P>
 *  Taken from More Servlets and JavaServer Pages
 *  from Prentice Hall and Sun Microsystems Press,
 *  http://www.moreservlets.com/.
 *  &copy; 2002 Marty Hall; may be freely used or adapted.
 */

public class CharArrayWrapper
             extends HttpServletResponseWrapper {
  private CharArrayWriter charWriter;

  /** Initializes wrapper.
   *  <P>
   *  First, this constructor calls the parent
   *  constructor. That call is crucial so that the response
   *  is stored and thus setHeader, setStatus, addCookie,
   *  and so forth work normally.
   *  <P>
   *  Second, this constructor creates a CharArrayWriter
   *  that will be used to accumulate the response.
   */
  
  public CharArrayWrapper(HttpServletResponse response) {
    super(response);
    charWriter = new CharArrayWriter();
  }

  /** When servlets or JSP pages ask for the Writer, 
   *  don't give them the real one. Instead, give them
   *  a version that writes into the character array.
   *  The filter needs to send the contents of the
   *  array to the client (perhaps after modifying it).
   */
  
  public PrintWriter getWriter() {
    return(new PrintWriter(charWriter));
  }

  /** Get a String representation of the entire buffer.
   *  <P>
   *  Be sure <B>not</B> to call this method multiple times
   *  on the same wrapper. The API for CharArrayWriter
   *  does not guarantee that it "remembers" the previous
   *  value, so the call is likely to make a new String
   *  every time.
   */
  
  public String toString() {
    return(charWriter.toString());
  }

  /** Get the underlying character array. */
  
  public char[] toCharArray() {
    return(charWriter.toCharArray());
  }
}