Java in a Nutshell, 5th Edition [Electronic resources] نسخه متنی

This
class represents a "protection
domain": the set of permissions associated with code
based on its source, and optionally, the identities of the users on
whose behalf the code is running. Use the
getProtectionDomain(
) of a Class object to obtain the
ProtectionDomain that the class is part of.

Prior to Java 1.4, a ProtectionDomain simply
associates a CodeSource with the
PermissionCollection granted to code from that
source by a Policy. The set of permissions is
static, and the implies(
)
method checks to see whether the specified
Permission is implied by any of the permissions
granted to this ProtectionDomain.

In Java 1.4 and later, a ProtectionDomain can also
be created with the four-argument constructor which associates a
PermissionCollection with a
ClassLoader and an array of
Principal objects in addition to a
CodeSource. A ProtectionDomain
of this sort represents permisssions granted to code loaded from a
specified source, through a specified class loader, and running under
the auspices of one or more specified principals. When a
ProtectionDomain is instantiated with this
four-argument constructor, the
PermissionCollection is not static, and the
implies( ) method calls the implies(
) method of the current Policy object
before checking the specified collection of permissions. This allows
security policies to be updated (for example to add new permissions
for specific users) without having to restart long-running programs
such as servers.

public class

ProtectionDomain {
// Public Constructors
public

ProtectionDomain (CodeSource

codesource ,
PermissionCollection

permissions );

1.4 public

ProtectionDomain (CodeSource

codesource ,
PermissionCollection

permissions , ClassLoader

classloader ,
Principal[ ]

principals );
// Public Instance Methods

1.4 public final ClassLoader

getClassLoader ( );
public final CodeSource

getCodeSource ( );
public final PermissionCollection

getPermissions ( );

1.4 public final Principal[ ]

getPrincipals ( );
public boolean

implies (Permission

permission );
// Public Methods Overriding Object
public String

toString ( );
}

Passed To

ClassLoader.defineClass( ),
java.lang.instrument.ClassFileTransformer.transform(
), AccessControlContext.AccessControlContext(
), DomainCombiner.combine( ),
java.security.Policy.{getPermissions( ),
implies( )},
javax.security.auth.SubjectDomainCombiner.combine(
)

Returned By

Class.getProtectionDomain( ),
DomainCombiner.combine( ),
javax.security.auth.SubjectDomainCombiner.combine(
)