/*
* $Id$
*
* Copyright (C) 2003-2014 JNode.org
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; If not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
package org.jnode.command.system;
import java.io.PrintWriter;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;
import java.net.URLClassLoader;
import java.security.AccessController;
import java.security.PrivilegedAction;
import org.jnode.shell.AbstractCommand;
import org.jnode.shell.syntax.Argument;
import org.jnode.shell.syntax.FlagArgument;
import org.jnode.shell.syntax.URLArgument;
/**
* @author Ewout Prangsma (epr@users.sourceforge.net)
* @author Levente S\u00e1ntha
* @author crawley@jnode.org
*/
public class ClasspathCommand extends AbstractCommand {
private static final String help_add = "the URL to be added to the classpath";
private static final String help_clear = "when set, clear the classpath";
private static final String help_refresh = "when set, cause classes to be reloaded on next use";
private static final String help_super = "Print, modify or refresh the classpath";
private final URLArgument argAdd;
private final FlagArgument argClear;
private final FlagArgument argRefresh;
public ClasspathCommand() {
super(help_super);
argAdd = new URLArgument("addUrl", Argument.OPTIONAL, help_add);
argClear = new FlagArgument("clear", Argument.OPTIONAL, help_clear);
argRefresh = new FlagArgument("refresh", Argument.OPTIONAL, help_refresh);
registerArguments(argAdd, argClear, argRefresh);
}
public static void main(String[] args) throws Exception {
new ClasspathCommand().execute(args);
}
@Override
public void execute() throws Exception {
if (argAdd.isSet()) {
addToClassPath(argAdd.getValue());
} else if (argClear.isSet()) {
clearClassPath();
} else if (argRefresh.isSet()) {
refreshClassPath();
} else {
printClassPath(getOutput().getPrintWriter());
}
}
private void refreshClassPath() {
URL[] urls = getClassLoader().getURLs();
clearClassPath();
if (urls != null) {
for (URL url : urls) {
try {
addToClassPath(url);
} catch (URISyntaxException e) {
e.printStackTrace();
}
}
}
}
private void addToClassPath(URL url) throws URISyntaxException {
URL[] urls = getClassLoader().getURLs();
if (urls != null) {
URI uri = url.toURI();
URI classLoaderUri;
for (URL u : urls) {
classLoaderUri = u.toURI();
if (classLoaderUri.equals(uri)) {
return;
}
}
}
getClassLoader().add(url);
}
private void clearClassPath() {
ClassLoader cl = Thread.currentThread().getContextClassLoader();
if (cl instanceof CPClassLoader) {
final ClassLoader cl2 = new CPClassLoader(cl.getParent());
AccessController.doPrivileged(new SetContextClassLoaderAction(cl2));
}
}
private void printClassPath(PrintWriter out) {
getClassLoader().print(out);
}
private CPClassLoader getClassLoader() {
ClassLoader cl = Thread.currentThread().getContextClassLoader();
if (!(cl instanceof CPClassLoader)) {
cl = new CPClassLoader(cl);
AccessController.doPrivileged(new SetContextClassLoaderAction(cl));
}
return (CPClassLoader) cl;
}
private static class CPClassLoader extends URLClassLoader {
/**
* @param parent the parent class loader
*/
public CPClassLoader(ClassLoader parent) {
super(new URL[0], parent);
}
public void add(URL url) {
addURL(url);
}
public void print(PrintWriter out) {
URL[] urls = getURLs();
if (urls != null) {
for (URL url : urls) {
out.println(url);
}
}
}
}
private static class SetContextClassLoaderAction implements PrivilegedAction<Object> {
private final ClassLoader classLoader;
public SetContextClassLoaderAction(ClassLoader classLoader) {
this.classLoader = classLoader;
}
@Override
public Object run() {
Thread.currentThread().setContextClassLoader(classLoader);
return null;
}
}
}