java.security
Class Policy

java.lang.Object
  |
  +--java.security.Policy

public abstract class Policy

extends Object

Untamed: This is an abstract class for representing the system security policy for a Java application environment (specifying which permissions are available for code from various sources). That is, the security policy is represented by a Policy subclass providing an implementation of the abstract methods in this Policy class.

There is only one Policy object in effect at any given time.

The source location for the policy information utilized by the Policy object is up to the Policy implementation. The policy configuration may be stored, for example, as a flat ASCII file, as a serialized binary file of the Policy class, or as a database.

The currently-installed Policy object can be obtained by calling the getPolicy method, and it can be changed by a call to the setPolicy method (by code with permission to reset the Policy).

The refresh method causes the policy object to refresh/reload its current configuration.

This is implementation-dependent. For example, if the policy object stores its policy in configuration files, calling refresh will cause it to re-read the configuration policy files. The refreshed policy may not have an effect on classes in a particular ProtectionDomain. This is dependent on the Policy provider's implementation of the implies method and the PermissionCollection caching strategy.

The default Policy implementation can be changed by setting the value of the "policy.provider" security property (in the Java security properties file) to the fully qualified name of the desired Policy implementation class. The Java security properties file is located in the file named <JAVA_HOME>/lib/security/java.security, where <JAVA_HOME> refers to the directory where the SDK was installed.

Version:

1.87, 12/03/01

Author:

Roland Schemers, Gary Ellison

See Also:

java.security.CodeSource, java.security.PermissionCollection, java.security.SecureClassLoader

Field Summary

private static sun.security.util.Debug	debug
private WeakHashMap	pdMapping
private static Policy	policy the system-wide policy.

Constructor Summary

Policy()
Enabled:

Method Summary

private void	addStaticPerms(PermissionCollection perms, PermissionCollection statics) add static permissions to provided permission collection
abstract PermissionCollection	getPermissions(CodeSource codesource) Enabled: Evaluates the global policy and returns a PermissionCollection object specifying the set of permissions allowed for code from the specified code source.
PermissionCollection	getPermissions(ProtectionDomain domain) Enabled: Evaluates the global policy and returns a PermissionCollection object specifying the set of permissions allowed given the characteristics of the protection domain.
static Policy	getPolicy() Enabled: Returns the installed Policy object.
(package private) static Policy	getPolicyNoCheck() Returns the installed Policy object, skipping the security check.
boolean	implies(ProtectionDomain domain, Permission permission) Enabled: Evaluates the global policy for the permissions granted to the ProtectionDomain and tests whether the permission is granted.
private static void	initPolicy(Policy p) Initialize superclass state such that a legacy provider can handle queries for itself.
(package private) static boolean	isSet() package private for AccessControlContext
abstract void	refresh() Enabled: Refreshes/reloads the policy configuration.
static void	setPolicy(Policy policy) Enabled: Sets the system-wide Policy object.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

policy

private static Policy policy

the system-wide policy.

debug

private static final sun.security.util.Debug debug

pdMapping

private WeakHashMap pdMapping

Constructor Detail

Policy

public Policy()

Enabled:

Method Detail

isSet

static boolean isSet()

package private for AccessControlContext

getPolicy

public static Policy getPolicy()

Enabled: Returns the installed Policy object. This value should not be cached, as it may be changed by a call to setPolicy. This method first calls SecurityManager.checkPermission with a SecurityPermission("getPolicy") permission to ensure it's ok to get the Policy object..

Returns:

the installed Policy.

Throws:

SecurityException - if a security manager exists and its checkPermission method doesn't allow getting the Policy object.

See Also:

SecurityManager.checkPermission(Permission), setPolicy(java.security.Policy)

getPolicyNoCheck

static Policy getPolicyNoCheck()

Returns the installed Policy object, skipping the security check. Used by SecureClassLoader and getPolicy.

Returns:

the installed Policy.

setPolicy

public static void setPolicy(Policy policy)

Enabled: Sets the system-wide Policy object. This method first calls SecurityManager.checkPermission with a SecurityPermission("setPolicy") permission to ensure it's ok to set the Policy.

Parameters:

policy - the new system Policy object.

Throws:

SecurityException - if a security manager exists and its checkPermission method doesn't allow setting the Policy.

See Also:

SecurityManager.checkPermission(Permission), getPolicy()

initPolicy

private static void initPolicy(Policy p)

Initialize superclass state such that a legacy provider can handle queries for itself.

Since:

1.4

getPermissions

public abstract PermissionCollection getPermissions(CodeSource codesource)

Enabled: Evaluates the global policy and returns a PermissionCollection object specifying the set of permissions allowed for code from the specified code source.

Parameters:

codesource - the CodeSource associated with the caller. This encapsulates the original location of the code (where the code came from) and the public key(s) of its signer.

Returns:

the set of permissions allowed for code from codesource according to the policy.The returned set of permissions must be a new mutable instance and it must support heterogeneous Permission types.

getPermissions

public PermissionCollection getPermissions(ProtectionDomain domain)

Enabled: Evaluates the global policy and returns a PermissionCollection object specifying the set of permissions allowed given the characteristics of the protection domain.

Parameters:

domain - the ProtectionDomain associated with the caller.

Returns:

the set of permissions allowed for the domain according to the policy.The returned set of permissions must be a new mutable instance and it must support heterogeneous Permission types.

Since:

1.4

See Also:

java.security.ProtectionDomain, java.security.SecureClassLoader

addStaticPerms

private void addStaticPerms(PermissionCollection perms,
                            PermissionCollection statics)

add static permissions to provided permission collection

implies

public boolean implies(ProtectionDomain domain,
                       Permission permission)

Enabled: Evaluates the global policy for the permissions granted to the ProtectionDomain and tests whether the permission is granted.

Parameters:

domain - the ProtectionDomain to test

permission - the Permission object to be tested for implication.

Returns:

true if "permission" is a proper subset of a permission granted to this ProtectionDomain.

Since:

1.4

See Also:

java.security.ProtectionDomain

refresh

public abstract void refresh()

Enabled: Refreshes/reloads the policy configuration. The behavior of this method depends on the implementation. For example, calling refresh on a file-based policy will cause the file to be re-read.