DefaultHttpResponse.java :  » Web-Server » asyncweb » org » safehaus » asyncweb » common » Java Open Source

/*
 *  Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you under the Apache License, Version 2.0 (the
 *  "License"); you may not use this file except in compliance
 *  with the License.  You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing,
 *  software distributed under the License is distributed on an
 *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 *  KIND, either express or implied.  See the License for the
 *  specific language governing permissions and limitations
 *  under the License.
 *
 */
package org.safehaus.asyncweb.common;

import org.safehaus.asyncweb.common.content.ByteBufferContent;
import org.safehaus.asyncweb.common.content.EmptyContent;
import org.safehaus.asyncweb.util.HttpDateFormat;
import org.safehaus.asyncweb.util.HttpHeaderConstants;


/**
 * A default implementation of {@link MutableHttpResponse}.
 * 
 * @author trustin
 * @version $Rev$, $Date$
 */
public class DefaultHttpResponse extends DefaultHttpMessage implements MutableHttpResponse {

  private static final long serialVersionUID = -3733889080525034446L;

  private HttpResponseStatus status = HttpResponseStatus.OK;
  private String statusReasonPhrase = HttpResponseStatus.OK.getDescription();

  /**
   * Creates a new instance
   *
   */
  public DefaultHttpResponse() {
  }
  
  public void addCookie(String headerValue) {
    // TODO Implement addCookie(String headerValue)
    throw new UnsupportedOperationException("Not implemented yet");
  }
    
  public HttpResponseStatus getStatus() {
    return status;
  }
  
  public void setStatus(HttpResponseStatus status) {
    setStatus(status, status.getDescription());
  }
  
  public void setStatus(HttpResponseStatus status, String statusReasonPhrase) {
    if (status == null) {
      throw new NullPointerException("status");
    }
    this.status = status;
    
    setStatusReasonPhrase(statusReasonPhrase);
  }
  
  public String getStatusReasonPhrase() {
    return statusReasonPhrase;
  }
  
  public void setStatusReasonPhrase(String statusReasonPhrase) {
    if (statusReasonPhrase == null) {
      throw new NullPointerException("statusReasonPhrase");
    }
    this.statusReasonPhrase = statusReasonPhrase;
  }

  public void normalize(HttpRequest request) {
    updateConnectionHeader(request);
    
    setHeader(HttpHeaderConstants.KEY_DATE, HttpDateFormat.getCurrentHttpDate());

    // FIXME Support other content types.
    int contentLength;
    if (isBodyAllowed(request) && getContent() instanceof ByteBufferContent) {
      contentLength = ((ByteBufferContent) getContent()).size();
    } else {
      setContent(EmptyContent.INSTANCE);
      contentLength = 0;
    }
    
    if (!containsHeader(HttpHeaderConstants.KEY_TRANSFER_CODING)) {
      setHeader(HttpHeaderConstants.KEY_CONTENT_LENGTH, String.valueOf(contentLength));
    }
  }

  /**
   * Updates our "Connection" header based on we are "keep-aliving" the connection
   * after the response.
   */
  private void updateConnectionHeader(HttpRequest request) {
    if (getStatus().forcesConnectionClosure()) {
      setHeader(HttpHeaderConstants.KEY_CONNECTION, HttpHeaderConstants.VALUE_CLOSE);
    } else if (request.isKeepAlive()) {
      setHeader(HttpHeaderConstants.KEY_CONNECTION, HttpHeaderConstants.VALUE_KEEP_ALIVE);
    } else {
      setHeader(HttpHeaderConstants.KEY_CONNECTION, HttpHeaderConstants.VALUE_CLOSE);
    }
  }
  
  /**
   * Determines whether we are allowed a response body.
   * A response body is allowed iff our response status allows a
   * body, and the original request method allows a body
   * 
   * @return  <code>true</code> if a body is allowed
   */
  private boolean isBodyAllowed(HttpRequest request) {
    HttpMethod method = request.getMethod();
    return getStatus().allowsMessageBody() && 
           method != null && method.isResponseBodyAllowed();
  }
}