/*
    * $Header: /home/cvs/jakarta-commons/httpclient/src/java/org/apache/commons/httpclient/util/HttpURLConnection.java,v 1.12.2.2 2004/02/22 18:21:16 olegk Exp $
    * $Revision: 1.12.2.2 $
    * $Date: 2004/02/22 18:21:16 $
    *
    * ====================================================================
    *
    *  Copyright 1999-2004 The Apache Software Foundation
    *
   *  Licensed 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.
   * ====================================================================
   *
   * This software consists of voluntary contributions made by many
   * individuals on behalf of the Apache Software Foundation.  For more
   * information on the Apache Software Foundation, please see
   * <http://www.apache.org/>.
   *
   * [Additional notices, if required by prior licensing conditions]
   *
   */
  
  package org.apache.commons.httpclient.util;
  
  import org.apache.commons.httpclient.HttpMethod;
  import org.apache.commons.httpclient.Header;
  
  import org.apache.commons.logging.LogFactory;
  import org.apache.commons.logging.Log;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.net.URL;
  import java.net.ProtocolException;
  import java.security.Permission;
  
  /***
   * Provides a <code>HttpURLConnection</code> wrapper around HttpClient's
   * <code>HttpMethod</code>. This allows existing code to easily switch to
   * HttpClieht without breaking existing interfaces using the JDK
   * <code>HttpURLConnection</code>.
   *
   * Note 1: The current implementations wraps only a connected
   * <code>HttpMethod</code>, ie a method that has alreayd been used to connect
   * to an HTTP server.
   *
   * Note 2: It is a best try effort as different version of the JDK have
   * different behaviours for <code>HttpURLConnection</code> (And I'm not even
   * including the numerous <code>HttpURLConnection</code> bugs!).
   *
   * @author <a href="mailto:vmassol@apache.org">Vincent Massol</a>
   * @author <a href="mailto:jsdever@apache.org">Jeff Dever</a>
   * @author <a href="mailto:mbowler@GargoyleSoftware.com">Mike Bowler</a>
   *
   * @since 2.0
   *
   * @version $Id: HttpURLConnection.java,v 1.12.2.2 2004/02/22 18:21:16 olegk Exp $
   */
  public class HttpURLConnection extends java.net.HttpURLConnection {
  
      // -------------------------------------------------------- Class Variables
     
      /*** Log object for this class. */
      private static final Log LOG = LogFactory.getLog(HttpURLConnection.class);
  
  
      // ----------------------------------------------------- Instance Variables
  
      /***
       * The <code>HttpMethod</code> object that was used to connect to the
       * HTTP server. It contains all the returned data.
       */
      private HttpMethod method;
  
      /***
       * The URL to which we are connected
       */
      private URL url;
  
  
  
      // ----------------------------------------------------------- Constructors
  
      /***
       * Creates an <code>HttpURLConnection</code> from a <code>HttpMethod</code>.
       *
       * @param method the theMethod that was used to connect to the HTTP
       *        server and which contains the returned data.
       * @param url the URL to which we are connected (includes query string)
       */
     public HttpURLConnection(HttpMethod method, URL url) {
         super(url);
         this.method = method;
         this.url = url;
     }
 
     /***
      * Create an instance.
      * @param url The URL.
      * @see java.net.HttpURLConnection#HttpURLConnection(URL)
      */
     protected HttpURLConnection(URL url) {
         super(url);
         throw new RuntimeException("An HTTP URL connection can only be "
             + "constructed from a HttpMethod class");
     }
 
 
     // --------------------------------------------------------- Public Methods
 
     /*** 
      * Gets an input stream for the HttpMethod response body.
      * @throws IOException If an IO problem occurs.
      * @return The input stream.
      * @see java.net.HttpURLConnection#getInputStream()
      * @see org.apache.commons.httpclient.HttpMethod#getResponseBodyAsStream()
      */
     public InputStream getInputStream() throws IOException {
         LOG.trace("enter HttpURLConnection.getInputStream()");
         return this.method.getResponseBodyAsStream();
     }
 
     /***
      * Not yet implemented.
      * Return the error stream.
      * @see java.net.HttpURLConnection#getErrorStream()
      */
     public InputStream getErrorStream() {
         LOG.trace("enter HttpURLConnection.getErrorStream()");
         throw new RuntimeException("Not implemented yet");
     }
 
     /***
      * Not yet implemented.
      * @see java.net.HttpURLConnection#disconnect()
      */
     public void disconnect() {
         LOG.trace("enter HttpURLConnection.disconnect()");
         throw new RuntimeException("Not implemented yet");
     }
 
     /***
      * Not available: the data must have already been retrieved.
      * @throws IOException If an IO problem occurs.
      * @see java.net.HttpURLConnection#connect()
      */
     public void connect() throws IOException {
         LOG.trace("enter HttpURLConnection.connect()");
         throw new RuntimeException("This class can only be used with already"
             + "retrieved data");
     }
 
     /***
      * Not yet implemented.
      * @return true if we are using a proxy.
      * @see java.net.HttpURLConnection#usingProxy()
      */
     public boolean usingProxy() {
         LOG.trace("enter HttpURLConnection.usingProxy()");
         throw new RuntimeException("Not implemented yet");
     }
 
     /***
      * Return the request method.
      * @return The request method.
      * @see java.net.HttpURLConnection#getRequestMethod()
      * @see org.apache.commons.httpclient.HttpMethod#getName()
      */
     public String getRequestMethod() {
         LOG.trace("enter HttpURLConnection.getRequestMethod()");
         return this.method.getName();
     }
 
     /***
      * Return the response code.
      * @return The response code.
      * @throws IOException If an IO problem occurs.
      * @see java.net.HttpURLConnection#getResponseCode()
      * @see org.apache.commons.httpclient.HttpMethod#getStatusCode()
      */
     public int getResponseCode() throws IOException {
         LOG.trace("enter HttpURLConnection.getResponseCode()");
         return this.method.getStatusCode();
     }
 
     /***
      * Return the response message
      * @return The response message
      * @throws IOException If an IO problem occurs.
      * @see java.net.HttpURLConnection#getResponseMessage()
      * @see org.apache.commons.httpclient.HttpMethod#getStatusText()
      */
     public String getResponseMessage() throws IOException {
         LOG.trace("enter HttpURLConnection.getResponseMessage()");
         return this.method.getStatusText();
     }
 
     /***
      * Return the header field
      * @param name the name of the header
      * @return the header field.
      * @see java.net.HttpURLConnection#getHeaderField(String)
      * @see org.apache.commons.httpclient.HttpMethod#getResponseHeaders()
      */
     public String getHeaderField(String name) {
         LOG.trace("enter HttpURLConnection.getHeaderField(String)");
         // Note: Return the last matching header in the Header[] array, as in
         // the JDK implementation.
         Header[] headers = this.method.getResponseHeaders();
         for (int i = headers.length - 1; i >= 0; i--) {
             if (headers[i].getName().equalsIgnoreCase(name)) {
                 return headers[i].getValue();
             }
         }
 
         return null;
     }
 
     /***
      * Return the header field key
      * @param keyPosition The key position
      * @return The header field key.
      * @see java.net.HttpURLConnection#getHeaderFieldKey(int)
      * @see org.apache.commons.httpclient.HttpMethod#getResponseHeaders()
      */
     public String getHeaderFieldKey(int keyPosition) {
         LOG.trace("enter HttpURLConnection.getHeaderFieldKey(int)");
 
         // Note: HttpClient does not consider the returned Status Line as
         // a response header. However, getHeaderFieldKey(0) is supposed to 
         // return null. Hence the special case below ...
         
         if (keyPosition == 0) {
             return null;
         }
 
         // Note: HttpClient does not currently keep headers in the same order
         // that they are read from the HTTP server.
 
         Header[] headers = this.method.getResponseHeaders();
         if (keyPosition < 0 || keyPosition > headers.length) {
             return null;
         }
 
         return headers[keyPosition - 1].getName();
     }
 
     /***
      * Return the header field at the specified position
      * @param position The position
      * @return The header field.
      * @see java.net.HttpURLConnection#getHeaderField(int)
      * @see org.apache.commons.httpclient.HttpMethod#getResponseHeaders()
      */
     public String getHeaderField(int position) {
         LOG.trace("enter HttpURLConnection.getHeaderField(int)");
 
         // Note: HttpClient does not consider the returned Status Line as
         // a response header. However, getHeaderField(0) is supposed to 
         // return the status line. Hence the special case below ...
         
         if (position == 0) {
             return this.method.getStatusLine().toString();
         }
 
         // Note: HttpClient does not currently keep headers in the same order
         // that they are read from the HTTP server.
 
         Header[] headers = this.method.getResponseHeaders();
         if (position < 0 || position > headers.length) {
             return null;
         }
 
         return headers[position - 1].getValue();
     }
 
     /***
      * Return the URL
      * @return The URL.
      * @see java.net.HttpURLConnection#getURL()
      */
     public URL getURL() {
         LOG.trace("enter HttpURLConnection.getURL()");
         return this.url;
     }
 
     // Note: We don't implement the following methods so that they default to
     // the JDK implementation. They will all call
     // <code>getHeaderField(String)</code> which we have overridden.
 
     // java.net.HttpURLConnection#getHeaderFieldDate(String, long)
     // java.net.HttpURLConnection#getContentLength()
     // java.net.HttpURLConnection#getContentType()
     // java.net.HttpURLConnection#getContentEncoding()
     // java.net.HttpURLConnection#getDate()
     // java.net.HttpURLConnection#getHeaderFieldInt(String, int)
     // java.net.HttpURLConnection#getExpiration()
     // java.net.HttpURLConnection#getLastModified()
 
     /***
      * Not available: the data must have already been retrieved.
      */
     public void setInstanceFollowRedirects(boolean isFollowingRedirects) {
         LOG.trace("enter HttpURLConnection.setInstanceFollowRedirects(boolean)");
         throw new RuntimeException("This class can only be used with already"
             + "retrieved data");
     }
 
     /***
      * Not yet implemented.
      */
     public boolean getInstanceFollowRedirects() {
         LOG.trace("enter HttpURLConnection.getInstanceFollowRedirects()");
         throw new RuntimeException("Not implemented yet");
     }
 
     /***
      * Not available: the data must have already been retrieved.
      * @see java.net.HttpURLConnection#setRequestMethod(String)
      */
     public void setRequestMethod(String method) throws ProtocolException {
         LOG.trace("enter HttpURLConnection.setRequestMethod(String)");
         throw new RuntimeException("This class can only be used with already"
             + "retrieved data");
     }
 
     /***
      * Not yet implemented.
      * @see java.net.HttpURLConnection#getPermission()
      */
     public Permission getPermission() throws IOException {
         LOG.trace("enter HttpURLConnection.getPermission()");
         throw new RuntimeException("Not implemented yet");
     }
 
     /***
      * Not yet implemented.
      * @see java.net.HttpURLConnection#getContent()
      */
     public Object getContent() throws IOException {
         LOG.trace("enter HttpURLConnection.getContent()");
         throw new RuntimeException("Not implemented yet");
     }
 
     /***
      * Not yet implemented.
      */
     public Object getContent(Class[] classes) throws IOException {
         LOG.trace("enter HttpURLConnection.getContent(Class[])");
         throw new RuntimeException("Not implemented yet");
     }
 
     /***
      * @see java.net.HttpURLConnection#getOutputStream()
      */
     public OutputStream getOutputStream() throws IOException {
         LOG.trace("enter HttpURLConnection.getOutputStream()");
         throw new RuntimeException("This class can only be used with already"
             + "retrieved data");
     }
 
     /***
      * Not available: the data must have already been retrieved.
      * @see java.net.HttpURLConnection#setDoInput(boolean)
      */
     public void setDoInput(boolean isInput) {
         LOG.trace("enter HttpURLConnection.setDoInput()");
         throw new RuntimeException("This class can only be used with already"
             + "retrieved data");
     }
 
     /***
      * Not yet implemented.
      * @see java.net.HttpURLConnection#getDoInput()
      */
     public boolean getDoInput() {
         LOG.trace("enter HttpURLConnection.getDoInput()");
         throw new RuntimeException("Not implemented yet");
     }
 
     /***
      * Not available: the data must have already been retrieved.
      * @see java.net.HttpURLConnection#setDoOutput(boolean)
      */
     public void setDoOutput(boolean isOutput) {
         LOG.trace("enter HttpURLConnection.setDoOutput()");
         throw new RuntimeException("This class can only be used with already"
             + "retrieved data");
     }
 
     /***
      * Not yet implemented.
      * @see java.net.HttpURLConnection#getDoOutput()
      */
     public boolean getDoOutput() {
         LOG.trace("enter HttpURLConnection.getDoOutput()");
         throw new RuntimeException("Not implemented yet");
     }
 
     /***
      * Not available: the data must have already been retrieved.
      * @see java.net.HttpURLConnection#setAllowUserInteraction(boolean)
      */
     public void setAllowUserInteraction(boolean isAllowInteraction) {
         LOG.trace("enter HttpURLConnection.setAllowUserInteraction(boolean)");
         throw new RuntimeException("This class can only be used with already"
             + "retrieved data");
     }
 
     /***
      * Not yet implemented.
      * @see java.net.HttpURLConnection#getAllowUserInteraction()
      */
     public boolean getAllowUserInteraction() {
         LOG.trace("enter HttpURLConnection.getAllowUserInteraction()");
         throw new RuntimeException("Not implemented yet");
     }
 
     /***
      * Not available: the data must have already been retrieved.
      * @see java.net.HttpURLConnection#setUseCaches(boolean)
      */
     public void setUseCaches(boolean isUsingCaches) {
         LOG.trace("enter HttpURLConnection.setUseCaches(boolean)");
         throw new RuntimeException("This class can only be used with already"
             + "retrieved data");
     }
 
     /***
      * Not yet implemented.
      * @see java.net.HttpURLConnection#getUseCaches()
      */
     public boolean getUseCaches() {
         LOG.trace("enter HttpURLConnection.getUseCaches()");
         throw new RuntimeException("Not implemented yet");
     }
 
     /***
      * Not available: the data must have already been retrieved.
      * @see java.net.HttpURLConnection#setIfModifiedSince(long)
      */
     public void setIfModifiedSince(long modificationDate) {
         LOG.trace("enter HttpURLConnection.setIfModifiedSince(long)");
         throw new RuntimeException("This class can only be used with already"
             + "retrieved data");
     }
 
     /***
      * Not yet implemented.
      * @see java.net.HttpURLConnection#getIfModifiedSince()
      */
     public long getIfModifiedSince() {
         LOG.trace("enter HttpURLConnection.getIfmodifiedSince()");
         throw new RuntimeException("Not implemented yet");
     }
 
     /***
      * Not available: the data must have already been retrieved.
      * @see java.net.HttpURLConnection#getDefaultUseCaches()
      */
     public boolean getDefaultUseCaches() {
         LOG.trace("enter HttpURLConnection.getDefaultUseCaches()");
         throw new RuntimeException("Not implemented yet");
     }
 
     /***
      * Not available: the data must have already been retrieved.
      * @see java.net.HttpURLConnection#setDefaultUseCaches(boolean)
      */
     public void setDefaultUseCaches(boolean isUsingCaches) {
         LOG.trace("enter HttpURLConnection.setDefaultUseCaches(boolean)");
         throw new RuntimeException("This class can only be used with already"
             + "retrieved data");
     }
 
     /***
      * Not available: the data must have already been retrieved.
      * @see java.net.HttpURLConnection#setRequestProperty(String,String)
      */
     public void setRequestProperty(String key, String value) {
         LOG.trace("enter HttpURLConnection.setRequestProperty()");
         throw new RuntimeException("This class can only be used with already"
             + "retrieved data");
     }
 
     /***
      * Not yet implemented.
      * @see java.net.HttpURLConnection#getRequestProperty(String)
      */
     public String getRequestProperty(String key) {
         LOG.trace("enter HttpURLConnection.getRequestProperty()");
         throw new RuntimeException("Not implemented yet");
     }
 
 }