org.eclipse.jgit.pgm.CommandRef Maven / Gradle / Ivy
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/*
* Copyright (C) 2008, Shawn O. Pearce
* 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.pgm;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.text.MessageFormat;
import org.eclipse.jgit.pgm.internal.CLIText;
/**
* Description of a command (a {@link TextBuiltin} subclass.
*
* These descriptions are lightweight compared to creating a command instance
* and are therefore suitable for catalogs of "known" commands without linking
* the command's implementation and creating a dummy instance of the command.
*/
public class CommandRef {
private final Class impl;
private final String name;
private String usage;
boolean common;
CommandRef(final Class clazz) {
this(clazz, guessName(clazz));
}
CommandRef(final Class clazz, final Command cmd) {
this(clazz, cmd.name().length() > 0 ? cmd.name() : guessName(clazz));
usage = cmd.usage();
common = cmd.common();
}
private CommandRef(final Class clazz, final String cn) {
impl = clazz;
name = cn;
usage = ""; //$NON-NLS-1$
}
private static String guessName(final Class clazz) {
final StringBuilder s = new StringBuilder();
if (clazz.getName().startsWith("org.eclipse.jgit.pgm.debug.")) //$NON-NLS-1$
s.append("debug-"); //$NON-NLS-1$
boolean lastWasDash = true;
for (final char c : clazz.getSimpleName().toCharArray()) {
if (Character.isUpperCase(c)) {
if (!lastWasDash)
s.append('-');
lastWasDash = !lastWasDash;
s.append(Character.toLowerCase(c));
} else {
s.append(c);
lastWasDash = false;
}
}
return s.toString();
}
/**
* @return name the command is invoked as from the command line.
*/
public String getName() {
return name;
}
/**
* @return one line description of the command's feature set.
*/
public String getUsage() {
return usage;
}
/**
* @return true if this command is considered to be commonly used.
*/
public boolean isCommon() {
return common;
}
/**
* @return name of the Java class which implements this command.
*/
public String getImplementationClassName() {
return impl.getName();
}
/**
* @return loader for {@link #getImplementationClassName()}.
*/
public ClassLoader getImplementationClassLoader() {
return impl.getClassLoader();
}
/**
* @return a new instance of the command implementation.
*/
public TextBuiltin create() {
final Constructor c;
try {
c = impl.getDeclaredConstructor();
} catch (SecurityException e) {
throw new RuntimeException(MessageFormat.format(CLIText.get().cannotCreateCommand, getName(), e));
} catch (NoSuchMethodException e) {
throw new RuntimeException(MessageFormat.format(CLIText.get().cannotCreateCommand, getName(), e));
}
c.setAccessible(true);
final TextBuiltin r;
try {
r = c.newInstance();
} catch (InstantiationException e) {
throw new RuntimeException(MessageFormat.format(CLIText.get().cannotCreateCommand, getName(), e));
} catch (IllegalAccessException e) {
throw new RuntimeException(MessageFormat.format(CLIText.get().cannotCreateCommand, getName(), e));
} catch (IllegalArgumentException e) {
throw new RuntimeException(MessageFormat.format(CLIText.get().cannotCreateCommand, getName(), e));
} catch (InvocationTargetException e) {
throw new RuntimeException(MessageFormat.format(CLIText.get().cannotCreateCommand, getName(), e));
}
r.setCommandName(getName());
return r;
}
}