org.eclipse.jgit.api.GitCommand Maven / Gradle / Ivy
/*
* Copyright (C) 2010, Christian Halstrick 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
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
package org.eclipse.jgit.api;
import java.text.MessageFormat;
import java.util.concurrent.Callable;
import org.eclipse.jgit.api.errors.GitAPIException;
import org.eclipse.jgit.internal.JGitText;
import org.eclipse.jgit.lib.Repository;
/**
* Common superclass of all commands in the package {@code org.eclipse.jgit.api}
*
* This class ensures that all commands fulfill the {@link Callable} interface.
* It also has a property {@link #repo} holding a reference to the git
* {@link Repository} this command should work with.
*
* Finally this class stores a state telling whether it is allowed to call
* {@link #call()} on this instance. Instances of {@link GitCommand} can only be
* used for one single successful call to {@link #call()}. Afterwards this
* instance may not be used anymore to set/modify any properties or to call
* {@link #call()} again. This is achieved by setting the {@link #callable}
* property to false after the successful execution of {@link #call()} and to
* check the state (by calling {@link #checkCallable()}) before setting of
* properties and inside {@link #call()}.
*
* @param
* the return type which is expected from {@link #call()}
*/
public abstract class GitCommand implements Callable {
/** The repository this command is working with */
final protected Repository repo;
/**
* a state which tells whether it is allowed to call {@link #call()} on this
* instance.
*/
private boolean callable = true;
/**
* Creates a new command which interacts with a single repository
*
* @param repo
* the {@link Repository} this command should interact with
*/
protected GitCommand(Repository repo) {
this.repo = repo;
}
/**
* @return the {@link Repository} this command is interacting with
*/
public Repository getRepository() {
return repo;
}
/**
* Set's the state which tells whether it is allowed to call {@link #call()}
* on this instance. {@link #checkCallable()} will throw an exception when
* called and this property is set to {@code false}
*
* @param callable
* if true it is allowed to call {@link #call()} on
* this instance.
*/
protected void setCallable(boolean callable) {
this.callable = callable;
}
/**
* Checks that the property {@link #callable} is {@code true}. If not then
* an {@link IllegalStateException} is thrown
*
* @throws IllegalStateException
* when this method is called and the property {@link #callable}
* is {@code false}
*/
protected void checkCallable() {
if (!callable)
throw new IllegalStateException(MessageFormat.format(
JGitText.get().commandWasCalledInTheWrongState
, this.getClass().getName()));
}
/**
* Executes the command
*
* @return T a result. Each command has its own return type
* @throws GitAPIException
* or subclass thereof when an error occurs
*/
public abstract T call() throws GitAPIException;
}