Java tutorial
/* * $Header: * /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons * //httpclient * /src/java/org/apache/commons/httpclient/util/HttpURLConnection.java,v 1.15 * 2004/04/18 23:51:38 jsdever Exp $ $Revision: 480424 $ $Date: 2006-11-29 * 06:56:49 +0100 (Wed, 29 Nov 2006) $ * * ==================================================================== * * 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. * ==================================================================== * * 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/>. */ package com.microsoft.tfs.core.httpclient.util; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.net.ProtocolException; import java.net.URL; import java.security.Permission; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import com.microsoft.tfs.core.httpclient.Header; import com.microsoft.tfs.core.httpclient.HttpMethod; /** * 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 480424 2006-11-29 05:56:49Z bayard $ */ 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(final HttpMethod method, final 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(final 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 com.microsoft.tfs.core.httpclient.HttpMethod#getResponseBodyAsStream() */ @Override public InputStream getInputStream() throws IOException { LOG.trace("enter HttpURLConnection.getInputStream()"); return method.getResponseBodyAsStream(); } /** * Not yet implemented. Return the error stream. * * @see java.net.HttpURLConnection#getErrorStream() */ @Override public InputStream getErrorStream() { LOG.trace("enter HttpURLConnection.getErrorStream()"); throw new RuntimeException("Not implemented yet"); } /** * Not yet implemented. * * @see java.net.HttpURLConnection#disconnect() */ @Override 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() */ @Override 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() */ @Override 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 com.microsoft.tfs.core.httpclient.HttpMethod#getName() */ @Override public String getRequestMethod() { LOG.trace("enter HttpURLConnection.getRequestMethod()"); return method.getName(); } /** * Return the response code. * * @return The response code. * @throws IOException * If an IO problem occurs. * @see java.net.HttpURLConnection#getResponseCode() * @see com.microsoft.tfs.core.httpclient.HttpMethod#getStatusCode() */ @Override public int getResponseCode() throws IOException { LOG.trace("enter HttpURLConnection.getResponseCode()"); return method.getStatusCode(); } /** * Return the response message * * @return The response message * @throws IOException * If an IO problem occurs. * @see java.net.HttpURLConnection#getResponseMessage() * @see com.microsoft.tfs.core.httpclient.HttpMethod#getStatusText() */ @Override public String getResponseMessage() throws IOException { LOG.trace("enter HttpURLConnection.getResponseMessage()"); return method.getStatusText(); } /** * Return the header field * * @param name * the name of the header * @return the header field. * @see java.net.HttpURLConnection#getHeaderField(String) * @see com.microsoft.tfs.core.httpclient.HttpMethod#getResponseHeaders() */ @Override public String getHeaderField(final String name) { LOG.trace("enter HttpURLConnection.getHeaderField(String)"); // Note: Return the last matching header in the Header[] array, as in // the JDK implementation. final Header[] headers = 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 com.microsoft.tfs.core.httpclient.HttpMethod#getResponseHeaders() */ @Override public String getHeaderFieldKey(final 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. final Header[] headers = 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 com.microsoft.tfs.core.httpclient.HttpMethod#getResponseHeaders() */ @Override public String getHeaderField(final 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 method.getStatusLine().toString(); } // Note: HttpClient does not currently keep headers in the same order // that they are read from the HTTP server. final Header[] headers = 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() */ @Override public URL getURL() { LOG.trace("enter HttpURLConnection.getURL()"); return 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. */ @Override public void setInstanceFollowRedirects(final boolean isFollowingRedirects) { LOG.trace("enter HttpURLConnection.setInstanceFollowRedirects(boolean)"); throw new RuntimeException("This class can only be used with already" + "retrieved data"); } /** * Not yet implemented. */ @Override 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) */ @Override public void setRequestMethod(final 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() */ @Override public Permission getPermission() throws IOException { LOG.trace("enter HttpURLConnection.getPermission()"); throw new RuntimeException("Not implemented yet"); } /** * Not yet implemented. * * @see java.net.HttpURLConnection#getContent() */ @Override public Object getContent() throws IOException { LOG.trace("enter HttpURLConnection.getContent()"); throw new RuntimeException("Not implemented yet"); } /** * Not yet implemented. */ @Override public Object getContent(final Class[] classes) throws IOException { LOG.trace("enter HttpURLConnection.getContent(Class[])"); throw new RuntimeException("Not implemented yet"); } /** * @see java.net.HttpURLConnection#getOutputStream() */ @Override 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) */ @Override public void setDoInput(final 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() */ @Override 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) */ @Override public void setDoOutput(final 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() */ @Override 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) */ @Override public void setAllowUserInteraction(final 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() */ @Override 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) */ @Override public void setUseCaches(final 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() */ @Override 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) */ @Override public void setIfModifiedSince(final 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() */ @Override 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() */ @Override 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) */ @Override public void setDefaultUseCaches(final 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) */ @Override public void setRequestProperty(final String key, final 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) */ @Override public String getRequestProperty(final String key) { LOG.trace("enter HttpURLConnection.getRequestProperty()"); throw new RuntimeException("Not implemented yet"); } }