View Javadoc
1   /*
2    * Copyright (C) 2015 Obeo.
3    * and other copyright owners as documented in the project's IP log.
4    *
5    * This program and the accompanying materials are made available
6    * under the terms of the Eclipse Distribution License v1.0 which
7    * accompanies this distribution, is reproduced below, and is
8    * available at http://www.eclipse.org/org/documents/edl-v10.php
9    *
10   * All rights reserved.
11   *
12   * Redistribution and use in source and binary forms, with or
13   * without modification, are permitted provided that the following
14   * conditions are met:
15   *
16   * - Redistributions of source code must retain the above copyright
17   *   notice, this list of conditions and the following disclaimer.
18   *
19   * - Redistributions in binary form must reproduce the above
20   *   copyright notice, this list of conditions and the following
21   *   disclaimer in the documentation and/or other materials provided
22   *   with the distribution.
23   *
24   * - Neither the name of the Eclipse Foundation, Inc. nor the
25   *   names of its contributors may be used to endorse or promote
26   *   products derived from this software without specific prior
27   *   written permission.
28   *
29   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
30   * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
31   * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
32   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
33   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
34   * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
35   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
36   * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
37   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
38   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
40   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
41   * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
42   */
43  package org.eclipse.jgit.hooks;
44  
45  import static java.nio.charset.StandardCharsets.UTF_8;
46  
47  import java.io.ByteArrayOutputStream;
48  import java.io.IOException;
49  import java.io.PrintStream;
50  import java.io.UnsupportedEncodingException;
51  import java.util.concurrent.Callable;
52  
53  import org.eclipse.jgit.api.errors.AbortedByHookException;
54  import org.eclipse.jgit.lib.Repository;
55  import org.eclipse.jgit.util.FS;
56  import org.eclipse.jgit.util.ProcessResult;
57  
58  /**
59   * Git can fire off custom scripts when certain important actions occur. These
60   * custom scripts are called "hooks". There are two groups of hooks: client-side
61   * (that run on local operations such as committing and merging), and
62   * server-side (that run on network operations such as receiving pushed
63   * commits). This is the abstract super-class of the different hook
64   * implementations in JGit.
65   *
66   * @param <T>
67   *            the return type which is expected from {@link #call()}
68   * @see <a href="http://git-scm.com/book/en/v2/Customizing-Git-Git-Hooks">Git
69   *      Hooks on the git-scm official site</a>
70   * @since 4.0
71   */
72  abstract class GitHook<T> implements Callable<T> {
73  
74  	private final Repository repo;
75  
76  	/**
77  	 * The output stream to be used by the hook.
78  	 */
79  	protected final PrintStream outputStream;
80  
81  	/**
82  	 * @param repo
83  	 * @param outputStream
84  	 *            The output stream the hook must use. {@code null} is allowed,
85  	 *            in which case the hook will use {@code System.out}.
86  	 */
87  	protected GitHook(Repository repo, PrintStream outputStream) {
88  		this.repo = repo;
89  		this.outputStream = outputStream;
90  	}
91  
92  	/**
93  	 * Run the hook.
94  	 *
95  	 * @throws IOException
96  	 *             if IO goes wrong.
97  	 * @throws AbortedByHookException
98  	 *             If the hook has been run and a returned an exit code
99  	 *             different from zero.
100 	 */
101 	@Override
102 	public abstract T call() throws IOException, AbortedByHookException;
103 
104 	/**
105 	 * @return The name of the hook, which must not be {@code null}.
106 	 */
107 	public abstract String getHookName();
108 
109 	/**
110 	 * @return The repository.
111 	 */
112 	protected Repository getRepository() {
113 		return repo;
114 	}
115 
116 	/**
117 	 * Override this method when needed to provide relevant parameters to the
118 	 * underlying hook script. The default implementation returns an empty
119 	 * array.
120 	 *
121 	 * @return The parameters the hook receives.
122 	 */
123 	protected String[] getParameters() {
124 		return new String[0];
125 	}
126 
127 	/**
128 	 * Override to provide relevant arguments via stdin to the underlying hook
129 	 * script. The default implementation returns {@code null}.
130 	 *
131 	 * @return The parameters the hook receives.
132 	 */
133 	protected String getStdinArgs() {
134 		return null;
135 	}
136 
137 	/**
138 	 * @return The output stream the hook must use. Never {@code null},
139 	 *         {@code System.out} is returned by default.
140 	 */
141 	protected PrintStream getOutputStream() {
142 		return outputStream == null ? System.out : outputStream;
143 	}
144 
145 	/**
146 	 * Runs the hook, without performing any validity checks.
147 	 *
148 	 * @throws AbortedByHookException
149 	 *             If the underlying hook script exited with non-zero.
150 	 */
151 	protected void doRun() throws AbortedByHookException {
152 		final ByteArrayOutputStream errorByteArray = new ByteArrayOutputStream();
153 		PrintStream hookErrRedirect = null;
154 		try {
155 			hookErrRedirect = new PrintStream(errorByteArray, false,
156 					UTF_8.name());
157 		} catch (UnsupportedEncodingException e) {
158 			// UTF-8 is guaranteed to be available
159 		}
160 		ProcessResult result = FS.DETECTED.runHookIfPresent(getRepository(),
161 				getHookName(), getParameters(), getOutputStream(),
162 				hookErrRedirect, getStdinArgs());
163 		if (result.isExecutedWithError()) {
164 			throw new AbortedByHookException(
165 					new String(errorByteArray.toByteArray(), UTF_8),
166 					getHookName(), result.getExitCode());
167 		}
168 	}
169 
170 }