/*
 * Copyright 2003-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
// $Id: SecuritySupport.java 226183 2005-04-08 10:39:14Z neeraj $

package javax.xml.validation;

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

/**
 * This class is duplicated for each JAXP subpackage so keep it in sync.
 * It is package private and therefore is not exposed as part of the JAXP
 * API.
 *
 * Security related methods that only work on J2SE 1.2 and newer.
 */
class SecuritySupport  {

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

    String getSystemProperty(final String propName) {
	return (String)
            AccessController.doPrivileged(new PrivilegedAction() {
                public Object run() {
                    return System.getProperty(propName);
                }
            });
    }

    FileInputStream getFileInputStream(final File file)
        throws FileNotFoundException
    {
	try {
            return (FileInputStream)
                AccessController.doPrivileged(new PrivilegedExceptionAction() {
                    public Object run() throws FileNotFoundException {
                        return new FileInputStream(file);
                    }
                });
	} catch (PrivilegedActionException e) {
	    throw (FileNotFoundException)e.getException();
	}
    }

    InputStream getURLInputStream(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();
	}
    }

    URL getResourceAsURL(final ClassLoader cl,
                                           final String name)
    {
        return (URL)
            AccessController.doPrivileged(new PrivilegedAction() {
                public Object run() {
                    URL url;
                    if (cl == null) {
                        url = ClassLoader.getSystemResource(name);
                    } else {
                        url = cl.getSystemResource(name);
                    }
                    return url;
                }
            });
    }

    Enumeration getResources(final ClassLoader cl,
                                           final String name) throws IOException
    {
        try{
        return (Enumeration)
            AccessController.doPrivileged(new PrivilegedExceptionAction() {
                public Object run() throws IOException{
                    Enumeration enumeration;
                    if (cl == null) {
                        enumeration = ClassLoader.getSystemResources(name);
                    } else {
                        enumeration = cl.getSystemResources(name);
                    }
                    return enumeration;
                }
            });
        }catch(PrivilegedActionException e){
            throw (IOException)e.getException();
        }
    }
    
    InputStream getResourceAsStream(final ClassLoader cl,
                                           final String name)
    {
        return (InputStream)
            AccessController.doPrivileged(new PrivilegedAction() {
                public Object run() {
                    InputStream ris;
                    if (cl == null) {
                        ris = ClassLoader.getSystemResourceAsStream(name);
                    } else {
                        ris = cl.getResourceAsStream(name);
                    }
                    return ris;
                }
            });
    }

    boolean doesFileExist(final File f) {
    return ((Boolean)
            AccessController.doPrivileged(new PrivilegedAction() {
                public Object run() {
                    return new Boolean(f.exists());
                }
            })).booleanValue();
    }

}
