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1   /*
2    * Copyright (C) 2010, Google Inc.
3    * Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org>
4    * and other copyright owners as documented in the project's IP log.
5    *
6    * This program and the accompanying materials are made available
7    * under the terms of the Eclipse Distribution License v1.0 which
8    * accompanies this distribution, is reproduced below, and is
9    * available at http://www.eclipse.org/org/documents/edl-v10.php
10   *
11   * All rights reserved.
12   *
13   * Redistribution and use in source and binary forms, with or
14   * without modification, are permitted provided that the following
15   * conditions are met:
16   *
17   * - Redistributions of source code must retain the above copyright
18   *   notice, this list of conditions and the following disclaimer.
19   *
20   * - Redistributions in binary form must reproduce the above
21   *   copyright notice, this list of conditions and the following
22   *   disclaimer in the documentation and/or other materials provided
23   *   with the distribution.
24   *
25   * - Neither the name of the Eclipse Foundation, Inc. nor the
26   *   names of its contributors may be used to endorse or promote
27   *   products derived from this software without specific prior
28   *   written permission.
29   *
30   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
31   * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
32   * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
33   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
34   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
35   * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
36   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
37   * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
38   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
39   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
40   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
41   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
42   * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
43   */
44  
45  package org.eclipse.jgit.util;
46  
47  import java.io.IOException;
48  import java.io.UnsupportedEncodingException;
49  import java.net.ConnectException;
50  import java.net.Proxy;
51  import java.net.ProxySelector;
52  import java.net.URISyntaxException;
53  import java.net.URL;
54  import java.net.URLEncoder;
55  import java.text.MessageFormat;
56  
57  import org.eclipse.jgit.internal.JGitText;
58  import org.eclipse.jgit.transport.http.HttpConnection;
59  
60  /** Extra utilities to support usage of HTTP. */
61  public class HttpSupport {
62  	/** The {@code GET} HTTP method. */
63  	public static final String METHOD_GET = "GET"; //$NON-NLS-1$
64  
65  	/** The {@code POST} HTTP method. */
66  	public static final String METHOD_POST = "POST"; //$NON-NLS-1$
67  
68  	/** The {@code Cache-Control} header. */
69  	public static final String HDR_CACHE_CONTROL = "Cache-Control"; //$NON-NLS-1$
70  
71  	/** The {@code Pragma} header. */
72  	public static final String HDR_PRAGMA = "Pragma"; //$NON-NLS-1$
73  
74  	/** The {@code User-Agent} header. */
75  	public static final String HDR_USER_AGENT = "User-Agent"; //$NON-NLS-1$
76  
77  	/**
78  	 * The {@code Server} header.
79  	 * @since 4.0
80  	 */
81  	public static final String HDR_SERVER = "Server"; //$NON-NLS-1$
82  
83  	/** The {@code Date} header. */
84  	public static final String HDR_DATE = "Date"; //$NON-NLS-1$
85  
86  	/** The {@code Expires} header. */
87  	public static final String HDR_EXPIRES = "Expires"; //$NON-NLS-1$
88  
89  	/** The {@code ETag} header. */
90  	public static final String HDR_ETAG = "ETag"; //$NON-NLS-1$
91  
92  	/** The {@code If-None-Match} header. */
93  	public static final String HDR_IF_NONE_MATCH = "If-None-Match"; //$NON-NLS-1$
94  
95  	/** The {@code Last-Modified} header. */
96  	public static final String HDR_LAST_MODIFIED = "Last-Modified"; //$NON-NLS-1$
97  
98  	/** The {@code If-Modified-Since} header. */
99  	public static final String HDR_IF_MODIFIED_SINCE = "If-Modified-Since"; //$NON-NLS-1$
100 
101 	/** The {@code Accept} header. */
102 	public static final String HDR_ACCEPT = "Accept"; //$NON-NLS-1$
103 
104 	/** The {@code Content-Type} header. */
105 	public static final String HDR_CONTENT_TYPE = "Content-Type"; //$NON-NLS-1$
106 
107 	/** The {@code Content-Length} header. */
108 	public static final String HDR_CONTENT_LENGTH = "Content-Length"; //$NON-NLS-1$
109 
110 	/** The {@code Content-Encoding} header. */
111 	public static final String HDR_CONTENT_ENCODING = "Content-Encoding"; //$NON-NLS-1$
112 
113 	/** The {@code Content-Range} header. */
114 	public static final String HDR_CONTENT_RANGE = "Content-Range"; //$NON-NLS-1$
115 
116 	/** The {@code Accept-Ranges} header. */
117 	public static final String HDR_ACCEPT_RANGES = "Accept-Ranges"; //$NON-NLS-1$
118 
119 	/** The {@code If-Range} header. */
120 	public static final String HDR_IF_RANGE = "If-Range"; //$NON-NLS-1$
121 
122 	/** The {@code Range} header. */
123 	public static final String HDR_RANGE = "Range"; //$NON-NLS-1$
124 
125 	/** The {@code Accept-Encoding} header. */
126 	public static final String HDR_ACCEPT_ENCODING = "Accept-Encoding"; //$NON-NLS-1$
127 
128 	/** The {@code gzip} encoding value for {@link #HDR_ACCEPT_ENCODING}. */
129 	public static final String ENCODING_GZIP = "gzip"; //$NON-NLS-1$
130 
131 	/** The standard {@code text/plain} MIME type. */
132 	public static final String TEXT_PLAIN = "text/plain"; //$NON-NLS-1$
133 
134 	/** The {@code Authorization} header. */
135 	public static final String HDR_AUTHORIZATION = "Authorization"; //$NON-NLS-1$
136 
137 	/** The {@code WWW-Authenticate} header. */
138 	public static final String HDR_WWW_AUTHENTICATE = "WWW-Authenticate"; //$NON-NLS-1$
139 
140 	/**
141 	 * URL encode a value string into an output buffer.
142 	 *
143 	 * @param urlstr
144 	 *            the output buffer.
145 	 * @param key
146 	 *            value which must be encoded to protected special characters.
147 	 */
148 	public static void encode(final StringBuilder urlstr, final String key) {
149 		if (key == null || key.length() == 0)
150 			return;
151 		try {
152 			urlstr.append(URLEncoder.encode(key, "UTF-8")); //$NON-NLS-1$
153 		} catch (UnsupportedEncodingException e) {
154 			throw new RuntimeException(JGitText.get().couldNotURLEncodeToUTF8, e);
155 		}
156 	}
157 
158 	/**
159 	 * Get the HTTP response code from the request.
160 	 * <p>
161 	 * Roughly the same as <code>c.getResponseCode()</code> but the
162 	 * ConnectException is translated to be more understandable.
163 	 *
164 	 * @param c
165 	 *            connection the code should be obtained from.
166 	 * @return r HTTP status code, usually 200 to indicate success. See
167 	 *         {@link HttpConnection} for other defined constants.
168 	 * @throws IOException
169 	 *             communications error prevented obtaining the response code.
170 	 * @since 3.3
171 	 */
172 	public static int response(final HttpConnection c) throws IOException {
173 		try {
174 			return c.getResponseCode();
175 		} catch (ConnectException ce) {
176 			final String host = c.getURL().getHost();
177 			// The standard J2SE error message is not very useful.
178 			//
179 			if ("Connection timed out: connect".equals(ce.getMessage())) //$NON-NLS-1$
180 				throw new ConnectException(MessageFormat.format(JGitText.get().connectionTimeOut, host));
181 			throw new ConnectException(ce.getMessage() + " " + host); //$NON-NLS-1$
182 		}
183 	}
184 
185 	/**
186 	 * Get the HTTP response code from the request.
187 	 * <p>
188 	 * Roughly the same as <code>c.getResponseCode()</code> but the
189 	 * ConnectException is translated to be more understandable.
190 	 *
191 	 * @param c
192 	 *            connection the code should be obtained from.
193 	 * @return r HTTP status code, usually 200 to indicate success. See
194 	 *         {@link HttpConnection} for other defined constants.
195 	 * @throws IOException
196 	 *             communications error prevented obtaining the response code.
197 	 */
198 	public static int response(final java.net.HttpURLConnection c)
199 			throws IOException {
200 		try {
201 			return c.getResponseCode();
202 		} catch (ConnectException ce) {
203 			final String host = c.getURL().getHost();
204 			// The standard J2SE error message is not very useful.
205 			//
206 			if ("Connection timed out: connect".equals(ce.getMessage())) //$NON-NLS-1$
207 				throw new ConnectException(MessageFormat.format(
208 						JGitText.get().connectionTimeOut, host));
209 			throw new ConnectException(ce.getMessage() + " " + host); //$NON-NLS-1$
210 		}
211 	}
212 
213 	/**
214 	 * Determine the proxy server (if any) needed to obtain a URL.
215 	 *
216 	 * @param proxySelector
217 	 *            proxy support for the caller.
218 	 * @param u
219 	 *            location of the server caller wants to talk to.
220 	 * @return proxy to communicate with the supplied URL.
221 	 * @throws ConnectException
222 	 *             the proxy could not be computed as the supplied URL could not
223 	 *             be read. This failure should never occur.
224 	 */
225 	public static Proxy proxyFor(final ProxySelector proxySelector, final URL u)
226 			throws ConnectException {
227 		try {
228 			return proxySelector.select(u.toURI()).get(0);
229 		} catch (URISyntaxException e) {
230 			final ConnectException err;
231 			err = new ConnectException(MessageFormat.format(JGitText.get().cannotDetermineProxyFor, u));
232 			err.initCause(e);
233 			throw err;
234 		}
235 	}
236 
237 	private HttpSupport() {
238 		// Utility class only.
239 	}
240 }