/*
 * Copyright (c) 2002, 2005, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code 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 General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package javax.activation;

import java.security.*;
import java.net.*;
import java.io.*;
import java.util.*;

/**
 * Security related methods that only work on J2SE 1.2 and newer.
 *
 * @since 1.6
 */
class SecuritySupport {

    private SecuritySupport() {
	// private constructor, can't create an instance
    }

    public static ClassLoader getContextClassLoader() {
	return (ClassLoader)
		AccessController.doPrivileged(new PrivilegedAction() {
	    public Object run() {
		ClassLoader cl = null;
		try {
		    cl = Thread.currentThread().getContextClassLoader();
		} catch (SecurityException ex) { }
		return cl;
	    }
	});
    }

    public static InputStream getResourceAsStream(final Class c,
				final String name) throws IOException {
	try {
	    return (InputStream)
		AccessController.doPrivileged(new PrivilegedExceptionAction() {
		    public Object run() throws IOException {
			return c.getResourceAsStream(name);
		    }
		});
	} catch (PrivilegedActionException e) {
	    throw (IOException)e.getException();
	}
    }

    public static URL[] getResources(final ClassLoader cl, final String name) {
	return (URL[])
		AccessController.doPrivileged(new PrivilegedAction() {
	    public Object run() {
		URL[] ret = null;
		try {
		    List v = new ArrayList();
		    Enumeration e = cl.getResources(name);
		    while (e != null && e.hasMoreElements()) {
			URL url = (URL)e.nextElement();
			if (url != null)
			    v.add(url);
		    }
		    if (v.size() > 0) {
			ret = new URL[v.size()];
			ret = (URL[])v.toArray(ret);
		    }
		} catch (IOException ioex) {
		} catch (SecurityException ex) { }
		return ret;
	    }
	});
    }

    public static URL[] getSystemResources(final String name) {
	return (URL[])
		AccessController.doPrivileged(new PrivilegedAction() {
	    public Object run() {
		URL[] ret = null;
		try {
		    List v = new ArrayList();
		    Enumeration e = ClassLoader.getSystemResources(name);
		    while (e != null && e.hasMoreElements()) {
			URL url = (URL)e.nextElement();
			if (url != null)
			    v.add(url);
		    }
		    if (v.size() > 0) {
			ret = new URL[v.size()];
			ret = (URL[])v.toArray(ret);
		    }
		} catch (IOException ioex) {
		} catch (SecurityException ex) { }
		return ret;
	    }
	});
    }

    public static InputStream openStream(final URL url) throws IOException {
	try {
	    return (InputStream)
		AccessController.doPrivileged(new PrivilegedExceptionAction() {
		    public Object run() throws IOException {
			return url.openStream();
		    }
		});
	} catch (PrivilegedActionException e) {
	    throw (IOException)e.getException();
	}
    }
}