javax.security.auth

Class Subject

java.lang.Object

javax.security.auth.Subject

All Implemented Interfaces:

java.io.Serializable

public final class Subject
extends java.lang.Object
implements java.io.Serializable

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
Subject()
Subject(boolean readOnly, java.util.Set<? extends java.security.Principal> principals, java.util.Set<?> pubCred, java.util.Set<?> privCred)

Method Summary

Methods

Modifier and Type	Method and Description
static java.lang.Object	doAs(Subject subject, java.security.PrivilegedAction action) Run a method as another subject.
static java.lang.Object	doAs(Subject subject, java.security.PrivilegedExceptionAction action) Run a method as another subject.
static java.lang.Object	doAsPrivileged(Subject subject, java.security.PrivilegedAction action, java.security.AccessControlContext acc) Run a method as another subject.
static java.lang.Object	doAsPrivileged(Subject subject, java.security.PrivilegedExceptionAction action, java.security.AccessControlContext acc) Run a method as another subject.
boolean	equals(java.lang.Object o) Determine whether this Object is semantically equal to another Object.
java.util.Set<java.security.Principal>	getPrincipals()
<T extends java.security.Principal> java.util.Set<T>	getPrincipals(java.lang.Class<T> clazz)
java.util.Set<java.lang.Object>	getPrivateCredentials()
<T> java.util.Set<T>	getPrivateCredentials(java.lang.Class<T> clazz)
java.util.Set<java.lang.Object>	getPublicCredentials()
<T> java.util.Set<T>	getPublicCredentials(java.lang.Class<T> clazz)
static Subject	getSubject(java.security.AccessControlContext context) Returns the subject associated with the given AccessControlContext.
int	hashCode() Get a value that represents this Object, as uniquely as possible within the confines of an int.
boolean	isReadOnly() Returns whether or not this subject is read-only.
void	setReadOnly() Marks this subject as read-only.
java.lang.String	toString() Convert this Object to a human-readable String.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

Subject

public Subject()

Subject

public Subject(boolean readOnly,
       java.util.Set<? extends java.security.Principal> principals,
       java.util.Set<?> pubCred,
       java.util.Set<?> privCred)

Method Detail

getSubject

public static Subject getSubject(java.security.AccessControlContext context)

Returns the subject associated with the given AccessControlContext.

All this method does is retrieve the Subject object from the supplied context's DomainCombiner, if any, and if it is an instance of a SubjectDomainCombiner.

Parameters:

context - The context to retrieve the subject from.

Returns:

The subject assoctiated with the context, or null if there is none.

Throws:

java.lang.NullPointerException - If subject is null.

java.lang.SecurityException - If the caller does not have permission to get the subject ("getSubject" target of AuthPermission.

doAs

public static java.lang.Object doAs(Subject subject,
                    java.security.PrivilegedAction action)

Run a method as another subject. This method will obtain the current AccessControlContext for this thread, then creates another with a SubjectDomainCombiner with the given subject. The supplied action will then be run with the modified context.

Parameters:

subject - The subject to run as.

action - The action to run.

Returns:

The value returned by the privileged action.

Throws:

java.lang.SecurityException - If the caller is not allowed to run under a different identity ("doAs" target of AuthPermission.

doAs

public static java.lang.Object doAs(Subject subject,
                    java.security.PrivilegedExceptionAction action)
                             throws java.security.PrivilegedActionException

Run a method as another subject. This method will obtain the current AccessControlContext for this thread, then creates another with a SubjectDomainCombiner with the given subject. The supplied action will then be run with the modified context.

Parameters:

subject - The subject to run as.

action - The action to run.

Returns:

The value returned by the privileged action.

Throws:

java.lang.SecurityException - If the caller is not allowed to run under a different identity ("doAs" target of AuthPermission.

java.security.PrivilegedActionException - If the action throws an exception.

doAsPrivileged

public static java.lang.Object doAsPrivileged(Subject subject,
                              java.security.PrivilegedAction action,
                              java.security.AccessControlContext acc)

Run a method as another subject. This method will create a new AccessControlContext derived from the given one, with a SubjectDomainCombiner with the given subject. The supplied action will then be run with the modified context.

Parameters:

subject - The subject to run as.

action - The action to run.

acc - The context to use.

Returns:

The value returned by the privileged action.

Throws:

java.lang.SecurityException - If the caller is not allowed to run under a different identity ("doAsPrivileged" target of AuthPermission.

doAsPrivileged

public static java.lang.Object doAsPrivileged(Subject subject,
                              java.security.PrivilegedExceptionAction action,
                              java.security.AccessControlContext acc)
                                       throws java.security.PrivilegedActionException

Run a method as another subject. This method will create a new AccessControlContext derived from the given one, with a SubjectDomainCombiner with the given subject. The supplied action will then be run with the modified context.

Parameters:

subject - The subject to run as.

action - The action to run.

acc - The context to use.

Returns:

The value returned by the privileged action.

Throws:

java.lang.SecurityException - If the caller is not allowed to run under a different identity ("doAsPrivileged" target of AuthPermission.

java.security.PrivilegedActionException - If the action throws an exception.

equals

public boolean equals(java.lang.Object o)

Description copied from class: java.lang.Object

Determine whether this Object is semantically equal to another Object.

There are some fairly strict requirements on this method which subclasses must follow:

• It must be transitive. If a.equals(b) and b.equals(c), then a.equals(c) must be true as well.
• It must be symmetric. a.equals(b) and b.equals(a) must have the same value.
• It must be reflexive. a.equals(a) must always be true.
• It must be consistent. Whichever value a.equals(b) returns on the first invocation must be the value returned on all later invocations.
• a.equals(null) must be false.
• It must be consistent with hashCode(). That is, a.equals(b) must imply a.hashCode() == b.hashCode(). The reverse is not true; two objects that are not equal may have the same hashcode, but that has the potential to harm hashing performance.

This is typically overridden to throw a ClassCastException if the argument is not comparable to the class performing the comparison, but that is not a requirement. It is legal for a.equals(b) to be true even though a.getClass() != b.getClass(). Also, it is typical to never cause a NullPointerException.

In general, the Collections API (java.util) use the equals method rather than the == operator to compare objects. However, IdentityHashMap is an exception to this rule, for its own good reasons.

The default implementation returns this == o.

Overrides:

equals in class java.lang.Object

Parameters:

o - the Object to compare to

Returns:

whether this Object is semantically equal to another

See Also:

Object.hashCode()

getPrincipals

public java.util.Set<java.security.Principal> getPrincipals()

getPrincipals

public <T extends java.security.Principal> java.util.Set<T> getPrincipals(java.lang.Class<T> clazz)

getPrivateCredentials

public java.util.Set<java.lang.Object> getPrivateCredentials()

getPrivateCredentials

public <T> java.util.Set<T> getPrivateCredentials(java.lang.Class<T> clazz)

getPublicCredentials

public java.util.Set<java.lang.Object> getPublicCredentials()

getPublicCredentials

public <T> java.util.Set<T> getPublicCredentials(java.lang.Class<T> clazz)

hashCode

public int hashCode()

Description copied from class: java.lang.Object

Get a value that represents this Object, as uniquely as possible within the confines of an int.

There are some requirements on this method which subclasses must follow:

• Semantic equality implies identical hashcodes. In other words, if a.equals(b) is true, then a.hashCode() == b.hashCode() must be as well. However, the reverse is not necessarily true, and two objects may have the same hashcode without being equal.
• It must be consistent. Whichever value o.hashCode() returns on the first invocation must be the value returned on all later invocations as long as the object exists. Notice, however, that the result of hashCode may change between separate executions of a Virtual Machine, because it is not invoked on the same object.

Notice that since hashCode is used in Hashtable and other hashing classes, a poor implementation will degrade the performance of hashing (so don't blindly implement it as returning a constant!). Also, if calculating the hash is time-consuming, a class may consider caching the results.

The default implementation returns System.identityHashCode(this)

Overrides:

hashCode in class java.lang.Object

Returns:

the hash code for this Object

See Also:

Object.equals(Object), System.identityHashCode(Object)

isReadOnly

public boolean isReadOnly()

Returns whether or not this subject is read-only.

Returns:

True is this subject is read-only.

setReadOnly

public void setReadOnly()

Marks this subject as read-only.

Throws:

java.lang.SecurityException - If the caller does not have permission to set this subject as read-only ("setReadOnly" target of AuthPermission.

toString

public java.lang.String toString()

Description copied from class: java.lang.Object

Convert this Object to a human-readable String. There are no limits placed on how long this String should be or what it should contain. We suggest you make it as intuitive as possible to be able to place it into System.out.println() and such.

It is typical, but not required, to ensure that this method never completes abruptly with a RuntimeException.

This method will be called when performing string concatenation with this object. If the result is null, string concatenation will instead use "null".

The default implementation returns getClass().getName() + "@" + Integer.toHexString(hashCode()).

Overrides:

toString in class java.lang.Object

Returns:

the String representing this Object, which may be null

See Also:

Object.getClass(), Object.hashCode(), Class.getName(), Integer.toHexString(int)