java.security

Class SecureClassLoader

Known Direct Subclasses:
URLClassLoader

public class SecureClassLoader
extends ClassLoader

A Secure Class Loader for loading classes with additional support for specifying code source and permissions when they are retrieved by the system policy handler.
Since:
1.2

Constructor Summary

SecureClassLoader()
Create a new ClassLoader with as parent the system classloader.
SecureClassLoader(ClassLoader parent)
Create a new ClassLoader with the specified parent.

Method Summary

protected Class
defineClass(String name, byte[] b, int off, int len, CodeSource cs)
Creates a class using an array of bytes and a CodeSource.
protected Class
defineClass(String name, ByteBuffer b, CodeSource cs)
Creates a class using an ByteBuffer and a CodeSource.
protected PermissionCollection
getPermissions(CodeSource cs)
Returns a PermissionCollection for the specified CodeSource.

Methods inherited from class java.lang.ClassLoader

clearAssertionStatus, defineClass, defineClass, defineClass, defineClass, definePackage, findClass, findLibrary, findLoadedClass, findResource, findResources, findSystemClass, getPackage, getPackages, getParent, getResource, getResourceAsStream, getResources, getSystemClassLoader, getSystemResource, getSystemResourceAsStream, getSystemResources, loadClass, loadClass, resolveClass, setClassAssertionStatus, setDefaultAssertionStatus, setPackageAssertionStatus, setSigners

Methods inherited from class java.lang.Object

clone, equals, extends Object> getClass, finalize, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

SecureClassLoader

protected SecureClassLoader()
Create a new ClassLoader with as parent the system classloader. There may be a security check for checkCreateClassLoader.
Throws:
SecurityException - if the security check fails

SecureClassLoader

protected SecureClassLoader(ClassLoader parent)
Create a new ClassLoader with the specified parent. The parent will be consulted when a class or resource is requested through loadClass() or getResource(). Only when the parent classloader cannot provide the requested class or resource the findClass() or findResource() method of this classloader will be called. There may be a security check for checkCreateClassLoader.
Parameters:
parent - the classloader's parent, or null for the bootstrap classloader
Throws:
SecurityException - if the security check fails
Since:
1.2

Method Details

defineClass

protected final Class defineClass(String name,
                                     byte[] b,
                                     int off,
                                     int len,
                                     CodeSource cs)
Creates a class using an array of bytes and a CodeSource.
Parameters:
name - the name to give the class. null if unknown.
b - the data representing the classfile, in classfile format.
off - the offset into the data where the classfile starts.
len - the length of the classfile data in the array.
cs - the CodeSource for the class or null when unknown.
Returns:
the class that was defined and optional CodeSource.

defineClass

protected final Class defineClass(String name,
                                     ByteBuffer b,
                                     CodeSource cs)
Creates a class using an ByteBuffer and a CodeSource.
Parameters:
name - the name to give the class. null if unknown.
b - the data representing the classfile, in classfile format.
cs - the CodeSource for the class or null when unknown.
Returns:
the class that was defined and optional CodeSource.
Since:
1.5

getPermissions

protected PermissionCollection getPermissions(CodeSource cs)
Returns a PermissionCollection for the specified CodeSource. The default implementation invokes java.security.Policy.getPermissions. This method is called by defineClass that takes a CodeSource argument to build a proper ProtectionDomain for the class being defined.

SecureClassLoader.java --- A Secure Class Loader Copyright (C) 1999, 2004, 2006 Free Software Foundation, Inc. This file is part of GNU Classpath. GNU Classpath is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GNU Classpath 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 for more details. You should have received a copy of the GNU General Public License along with GNU Classpath; see the file COPYING. If not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. Linking this library statically or dynamically with other modules is making a combined work based on this library. Thus, the terms and conditions of the GNU General Public License cover the whole combination. As a special exception, the copyright holders of this library give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you may extend this exception to your version of the library, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version.