java.security
Class SecureClassLoader

java.lang.Object
  |
  +--java.lang.ClassLoader
        |
        +--java.security.SecureClassLoader
Direct Known Subclasses:
URLClassLoader

public class SecureClassLoader
extends ClassLoader

Untamed: This class extends ClassLoader with additional support for defining classes with an associated code source and permissions which are retrieved by the system policy by default.

Version:
1.81, 12/03/01
Author:
Li Gong, Roland Schemers

Field Summary
private static sun.security.util.Debug debug
           
private  boolean initialized
           
private  HashMap pdcache
           
 
Fields inherited from class java.lang.ClassLoader
 
Constructor Summary
protected SecureClassLoader()
          Creates a new SecureClassLoader using the default parent class loader for delegation.
protected SecureClassLoader(ClassLoader parent)
          Creates a new SecureClassLoader using the specified parent class loader for delegation.
 
Method Summary
private  void check()
           
protected  Class defineClass(String name, byte[] b, int off, int len, CodeSource cs)
          Converts an array of bytes into an instance of class Class, with an optional CodeSource.
protected  PermissionCollection getPermissions(CodeSource codesource)
          Returns the permissions for the given CodeSource object.
private  ProtectionDomain getProtectionDomain(CodeSource cs)
           
 
Methods inherited from class java.lang.ClassLoader
clearAssertionStatus, 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, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

initialized

private boolean initialized

pdcache

private HashMap pdcache

debug

private static final sun.security.util.Debug debug
Constructor Detail

SecureClassLoader

protected SecureClassLoader(ClassLoader parent)
Creates a new SecureClassLoader using the specified parent class loader for delegation.

If there is a security manager, this method first calls the security manager's checkCreateClassLoader method to ensure creation of a class loader is allowed.

Parameters:
parent - the parent ClassLoader
See Also:
SecurityManager.checkCreateClassLoader()

SecureClassLoader

protected SecureClassLoader()
Creates a new SecureClassLoader using the default parent class loader for delegation.

If there is a security manager, this method first calls the security manager's checkCreateClassLoader method to ensure creation of a class loader is allowed.

See Also:
SecurityManager.checkCreateClassLoader()
Method Detail

defineClass

protected final Class defineClass(String name,
                                  byte[] b,
                                  int off,
                                  int len,
                                  CodeSource cs)
Converts an array of bytes into an instance of class Class, with an optional CodeSource. Before the class can be used it must be resolved.

If a non-null CodeSource is supplied a ProtectionDomain is constructed and associated with the class being defined.

Parameters:
name - the expected name of the class, or null if not known, using '.' and not '/' as the separator and without a trailing ".class" suffix.
b - the bytes that make up the class data. The bytes in positions off through off+len-1 should have the format of a valid class file as defined by the Java Virtual Machine Specification.
off - the start offset in b of the class data
len - the length of the class data
cs - the associated CodeSource, or null if none
Returns:
the Class object created from the data, and optional CodeSource.

getPermissions

protected PermissionCollection getPermissions(CodeSource codesource)
Returns the permissions for the given CodeSource object.

This method is invoked by the defineClass method which takes a CodeSource as an argument when it is constructing the ProtectionDomain for the class being defined.

Parameters:
codesource - the codesource.
Returns:
the permissions granted to the codesource.

getProtectionDomain

private ProtectionDomain getProtectionDomain(CodeSource cs)

check

private void check()


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