Add GitCheckoutTask to org.eclipse.jgit.ant

Bug: 321237
Change-Id: I5c4753f7b99d0be002b32e403f5dfff9353c57b0
Signed-off-by: Chris Aniszczyk <caniszczyk@gmail.com>

org.eclipse.jgit.ant/resources/org/eclipse/jgit/ant/ant-tasks.properties

@@ -1,2 +1,3 @@
 git-init=org.eclipse.jgit.ant.tasks.GitInitTask
 git-clone=org.eclipse.jgit.ant.tasks.GitCloneTask
+git-checkout=org.eclipse.jgit.ant.tasks.GitCheckoutTask

org.eclipse.jgit.ant/src/org/eclipse/jgit/ant/tasks/GitCheckoutTask.java

@@ -0,0 +1,126 @@
+/*
+ * Copyright (C) 2011, Ketan Padegaonkar <KetanPadegaonkar@gmail.com>
+ * and other copyright owners as documented in the project's IP log.
+ *
+ * This program and the accompanying materials are made available
+ * under the terms of the Eclipse Distribution License v1.0 which
+ * accompanies this distribution, is reproduced below, and is
+ * available at http://www.eclipse.org/org/documents/edl-v10.php
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ *   copyright notice, this list of conditions and the following
+ *   disclaimer in the documentation and/or other materials provided
+ *   with the distribution.
+ *
+ * - Neither the name of the Eclipse Foundation, Inc. nor the
+ *   names of its contributors may be used to endorse or promote
+ *   products derived from this software without specific prior
+ *   written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package org.eclipse.jgit.ant.tasks;
+
+import java.io.File;
+import java.io.IOException;
+
+import org.apache.tools.ant.BuildException;
+import org.apache.tools.ant.Task;
+import org.eclipse.jgit.api.CheckoutCommand;
+import org.eclipse.jgit.api.Git;
+import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.storage.file.FileRepositoryBuilder;
+
+/**
+ * Checkout a branch or paths to the working tree.
+ * 
+ * @see <a
+ *      href="http://www.kernel.org/pub/software/scm/git/docs/git-checkout.html"
+ *      >git-checkout(1)</a>
+ */
+public class GitCheckoutTask extends Task {
+
+	private File src;
+	private String branch;
+	private boolean createBranch;
+	private boolean force;
+
+	/**
+	 * @param src
+	 *            the src to set
+	 */
+	public void setSrc(File src) {
+		this.src = src;
+	}
+
+	/**
+	 * @param branch
+	 *            the initial branch to check out
+	 */
+	public void setBranch(String branch) {
+		this.branch = branch;
+	}
+
+	/**
+	 * @param createBranch
+	 *            whether the branch should be created if it does not already
+	 *            exist
+	 */
+	public void setCreateBranch(boolean createBranch) {
+		this.createBranch = createBranch;
+	}
+
+	/**
+	 * @param force
+	 *            if <code>true</code> and the branch with the given name
+	 *            already exists, the start-point of an existing branch will be
+	 *            set to a new start-point; if false, the existing branch will
+	 *            not be changed
+	 * @return this instance
+	 */
+	public void setForce(boolean force) {
+		this.force = force;
+	}
+
+	@Override
+	public void execute() throws BuildException {
+		CheckoutCommand checkout;
+		try {
+			Repository repo = new FileRepositoryBuilder().readEnvironment()
+					.findGitDir(src).build();
+			checkout = new Git(repo).checkout();
+		} catch (IOException e) {
+			throw new BuildException("Could not access repository " + src, e);
+		}
+
+		try {
+			checkout.setCreateBranch(createBranch).setForce(force)
+					.setName(branch);
+			checkout.call();
+		} catch (Exception e) {
+			throw new BuildException("Could not checkout repository " + src, e);
+		}
+	}
+
+}