/*
    WebBox - Dein Server.
    Copyright (C) 2017 Ulrich Hilger, http://uhilger.de

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU Affero General Public License as
    published by the Free Software Foundation, either version 3 of the
    License, or (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Affero General Public License for more details.

    You should have received a copy of the GNU Affero General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package de.uhilger.wbx.web;

import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServletResponseWrapper;

/**
 * Die Klasse CustomResponseWrapper faengt den Inhalt einer HttpServletResponse
 * in einem StringWriter auf. Dieser kann mit der Methode getResponseContent 
 * gelesen werden.
 *
 * @author ulrich
 */
public class CustomResponseWrapper extends HttpServletResponseWrapper {

  private StringWriter stringWriter;
  private boolean isOutputStreamCalled;

  public CustomResponseWrapper(HttpServletResponse response) {
    super(response);
  }

  @Override
  public ServletOutputStream getOutputStream() throws IOException {
    if (this.stringWriter != null) {
      throw new IllegalStateException("The getWriter() is already called.");
    }
    isOutputStreamCalled = true;
    return super.getOutputStream();
  }

  @Override
  public PrintWriter getWriter() throws IOException {
    if (isOutputStreamCalled) {
      throw new IllegalStateException("The getOutputStream() is already called.");
    }

    this.stringWriter = new StringWriter();

    return new PrintWriter(this.stringWriter);
  }

  public String getResponseContent() {
    if (this.stringWriter != null) {
      return this.stringWriter.toString();
    }
    return "";
  }

}