Class Subject
- All Implemented Interfaces:
Serializable
A Subject
represents a grouping of related information
for a single entity, such as a person.
Such information includes the Subject's identities as well as
its security-related attributes
(passwords and cryptographic keys, for example).
Subjects may potentially have multiple identities.
Each identity is represented as a Principal
within the Subject
. Principals simply bind names to a
Subject
. For example, a Subject
that happens
to be a person, Alice, might have two Principals:
one which binds "Alice Bar", the name on her driver license,
to the Subject
, and another which binds,
"999-99-9999", the number on her student identification card,
to the Subject
. Both Principals refer to the same
Subject
even though each has a different name.
A Subject
may also own security-related attributes,
which are referred to as credentials.
Sensitive credentials that require special protection, such as
private cryptographic keys, are stored within a private credential
Set
. Credentials intended to be shared, such as
public key certificates or Kerberos server tickets are stored
within a public credential Set
.
To retrieve all the Principals associated with a Subject
,
invoke the getPrincipals
method. To retrieve
all the public or private credentials belonging to a Subject
,
invoke the getPublicCredentials
method or
getPrivateCredentials
method, respectively.
To modify the returned Set
of Principals and credentials,
use the methods defined in the Set
class.
For example:
Subject subject; Principal principal; Object credential; // add a Principal and credential to the Subject subject.getPrincipals().add(principal); subject.getPublicCredentials().add(credential);
This Subject
class implements Serializable
.
While the Principals associated with the Subject
are serialized,
the credentials associated with the Subject
are not.
Note that the java.security.Principal
class
does not implement Serializable
. Therefore, all concrete
Principal
implementations associated with Subjects
must implement Serializable
.
Deprecated Methods and Replacements
The following methods in this class for user-based authorization that are dependent on Security Manager APIs are deprecated for removal:
getSubject(AccessControlContext)
doAs(Subject, PrivilegedAction)
doAs(Subject, PrivilegedExceptionAction)
doAsPrivileged(Subject, PrivilegedAction, AccessControlContext)
doAsPrivileged(Subject, PrivilegedExceptionAction, AccessControlContext)
current()
and callAs(Subject, Callable)
are replacements for these methods, where current
is equivalent to
getSubject(AccessController.getContext())
(as originally specified)
and callAs
is similar to doAs
except that the
input type and exceptions thrown are slightly different.
A doAs
or callAs
call
binds a Subject
object to the period of execution of an action,
and the subject can be retrieved using the current
method inside
the action. This subject can be inherited by child threads if they are
started and terminate within the execution of its parent thread using
structured concurrency.
- Since:
- 1.4
- See Also:
-
Constructor Summary
ConstructorDescriptionSubject()
Create an instance of aSubject
with an emptySet
of Principals and empty Sets of public and private credentials.Subject
(boolean readOnly, Set<? extends Principal> principals, Set<?> pubCredentials, Set<?> privCredentials) Create an instance of aSubject
with Principals and credentials. -
Method Summary
Modifier and TypeMethodDescriptionstatic <T> T
Executes aCallable
withsubject
as the current subject.static Subject
current()
Returns the current subject.static <T> T
doAs
(Subject subject, PrivilegedAction<T> action) Deprecated, for removal: This API element is subject to removal in a future version.static <T> T
doAs
(Subject subject, PrivilegedExceptionAction<T> action) Deprecated, for removal: This API element is subject to removal in a future version.This method originally performed the specifiedPrivilegedExceptionAction
with privileges enabled.static <T> T
doAsPrivileged
(Subject subject, PrivilegedAction<T> action, AccessControlContext acc) Deprecated, for removal: This API element is subject to removal in a future version.This method originally performed the specifiedPrivilegedAction
with privileges enabled and restricted by the specifiedAccessControlContext
.static <T> T
doAsPrivileged
(Subject subject, PrivilegedExceptionAction<T> action, AccessControlContext acc) Deprecated, for removal: This API element is subject to removal in a future version.This method originally performed the specifiedPrivilegedExceptionAction
with privileges enabled and restricted by the specifiedAccessControlContext
.boolean
Compares the specified Object with thisSubject
for equality.Return theSet
of Principals associated with thisSubject
.getPrincipals
(Class<T> c) Return aSet
of Principals associated with thisSubject
that are instances or subclasses of the specifiedClass
.Return theSet
of private credentials held by thisSubject
.<T> Set
<T> getPrivateCredentials
(Class<T> c) Return aSet
of private credentials associated with thisSubject
that are instances or subclasses of the specifiedClass
.Return theSet
of public credentials held by thisSubject
.<T> Set
<T> getPublicCredentials
(Class<T> c) Return aSet
of public credentials associated with thisSubject
that are instances or subclasses of the specifiedClass
.static Subject
Deprecated, for removal: This API element is subject to removal in a future version.This method used to get the subject associated with the providedAccessControlContext
, which was only useful in conjunction with the Security Manager, which is no longer supported.int
hashCode()
Returns a hashcode for thisSubject
.boolean
Query whether thisSubject
is read-only.void
Set thisSubject
to be read-only.toString()
Return the String representation of thisSubject
.
-
Constructor Details
-
Subject
public Subject()Create an instance of aSubject
with an emptySet
of Principals and empty Sets of public and private credentials.The newly constructed Sets check whether this
Subject
has been set read-only before permitting subsequent modifications. These Sets also prohibit null elements, and attempts to add, query, or remove a null element will result in aNullPointerException
. -
Subject
public Subject(boolean readOnly, Set<? extends Principal> principals, Set<?> pubCredentials, Set<?> privCredentials) Create an instance of aSubject
with Principals and credentials.The Principals and credentials from the specified Sets are copied into newly constructed Sets. These newly created Sets check whether this
Subject
has been set read-only before permitting subsequent modifications. These Sets also prohibit null elements, and attempts to add, query, or remove a null element will result in aNullPointerException
.- Parameters:
readOnly
- true if theSubject
is to be read-only, and false otherwise.principals
- theSet
of Principals to be associated with thisSubject
.pubCredentials
- theSet
of public credentials to be associated with thisSubject
.privCredentials
- theSet
of private credentials to be associated with thisSubject
.- Throws:
NullPointerException
- if the specifiedprincipals
,pubCredentials
, orprivCredentials
arenull
, or a null value exists within any of these three Sets.
-
-
Method Details
-
setReadOnly
public void setReadOnly()Set thisSubject
to be read-only.Modifications (additions and removals) to this Subject's
Principal
Set
and credential Sets will be disallowed. Thedestroy
operation on this Subject's credentials will still be permitted.Subsequent attempts to modify the Subject's
Principal
and credential Sets will result in anIllegalStateException
being thrown. Also, once aSubject
is read-only, it can not be reset to being writable again. -
isReadOnly
public boolean isReadOnly()Query whether thisSubject
is read-only.- Returns:
- true if this
Subject
is read-only, false otherwise.
-
getSubject
Deprecated, for removal: This API element is subject to removal in a future version.This method used to get the subject associated with the providedAccessControlContext
, which was only useful in conjunction with the Security Manager, which is no longer supported. This method has been changed to always throwUnsupportedOperationException
. A replacement API namedcurrent()
has been added which can be used to obtain the current subject. There is no replacement for the Security Manager.ThrowsUnsupportedOperationException
. A replacement API namedcurrent()
has been added which can be used to obtain the current subject.- Parameters:
acc
- ignored- Returns:
- n/a
- Throws:
UnsupportedOperationException
- always- See Also:
-
current
Returns the current subject.The current subject is installed by the
callAs(javax.security.auth.Subject, java.util.concurrent.Callable<T>)
method. WhencallAs(subject, action)
is called,action
is executed withsubject
as its current subject which can be retrieved by this method. Afteraction
is finished, the current subject is reset to its previous value. The current subject isnull
before the first call ofcallAs()
.This method returns the
Subject
bound to the period of the execution of the current thread.- Returns:
- the current subject, or
null
if a current subject is not installed or the current subject is set tonull
. - Since:
- 18
- See Also:
-
callAs
Executes aCallable
withsubject
as the current subject.This method launches
action
and bindssubject
to the period of its execution.- Type Parameters:
T
- the type of value returned by thecall
method ofaction
- Parameters:
subject
- theSubject
that the specifiedaction
will run as. This parameter may benull
.action
- the code to be run withsubject
as its current subject. Must not benull
.- Returns:
- the value returned by the
call
method ofaction
- Throws:
NullPointerException
- ifaction
isnull
CompletionException
- ifaction.call()
throws an exception. The cause of theCompletionException
is set to the exception thrown byaction.call()
.- Since:
- 18
- See Also:
-
doAs
@Deprecated(since="18", forRemoval=true) public static <T> T doAs(Subject subject, PrivilegedAction<T> action) Deprecated, for removal: This API element is subject to removal in a future version.This method originally performed the specifiedPrivilegedAction
with privileges enabled. Running the action with privileges enabled was only useful in conjunction with the Security Manager, which is no longer supported. This method has been changed to launch the action as is and bind the subject to the period of its execution. A replacement API namedcallAs(javax.security.auth.Subject, java.util.concurrent.Callable<T>)
has been added which can be used to perform the same work. There is no replacement for the Security Manager.Perform work as a particularSubject
.This method launches
action
and bindssubject
to the period of its execution.- Type Parameters:
T
- the type of the value returned by the PrivilegedAction'srun
method.- Parameters:
subject
- theSubject
that the specifiedaction
will run as. This parameter may benull
.action
- the code to be run as the specifiedSubject
.- Returns:
- the value returned by the PrivilegedAction's
run
method. - Throws:
NullPointerException
- if thePrivilegedAction
isnull
.- See Also:
-
doAs
@Deprecated(since="18", forRemoval=true) public static <T> T doAs(Subject subject, PrivilegedExceptionAction<T> action) throws PrivilegedActionException Deprecated, for removal: This API element is subject to removal in a future version.This method originally performed the specifiedPrivilegedExceptionAction
with privileges enabled. Running the action with privileges enabled was only useful in conjunction with the Security Manager, which is no longer supported. This method has been changed to launch the action as is and bind the subject to the period of its execution. A replacement API namedcallAs(javax.security.auth.Subject, java.util.concurrent.Callable<T>)
has been added which can be used to perform the same work. There is no replacement for the Security Manager.Perform work as a particularSubject
.This method launches
action
and bindssubject
to the period of its execution.- Type Parameters:
T
- the type of the value returned by the PrivilegedExceptionAction'srun
method.- Parameters:
subject
- theSubject
that the specifiedaction
will run as. This parameter may benull
.action
- the code to be run as the specifiedSubject
.- Returns:
- the value returned by the
PrivilegedExceptionAction's
run
method. - Throws:
PrivilegedActionException
- if thePrivilegedExceptionAction.run
method throws a checked exception.NullPointerException
- if the specifiedPrivilegedExceptionAction
isnull
.- See Also:
-
doAsPrivileged
@Deprecated(since="17", forRemoval=true) public static <T> T doAsPrivileged(Subject subject, PrivilegedAction<T> action, AccessControlContext acc) Deprecated, for removal: This API element is subject to removal in a future version.This method originally performed the specifiedPrivilegedAction
with privileges enabled and restricted by the specifiedAccessControlContext
. Running the action with privileges enabled was only useful in conjunction with the Security Manager, which is no longer supported. This method has been changed to ignore theAccessControlContext
and launch the action as is and bind the subject to the period of its execution. A replacement API namedcallAs(javax.security.auth.Subject, java.util.concurrent.Callable<T>)
has been added which can be used to perform the same work. There is no replacement for the Security Manager.Perform privileged work as a particularSubject
.This method launches
action
and bindssubject
to the period of its execution.- Type Parameters:
T
- the type of the value returned by the PrivilegedAction'srun
method.- Parameters:
subject
- theSubject
that the specifiedaction
will run as. This parameter may benull
.action
- the code to be run as the specifiedSubject
.acc
- ignored- Returns:
- the value returned by the PrivilegedAction's
run
method. - Throws:
NullPointerException
- if thePrivilegedAction
isnull
.- See Also:
-
doAsPrivileged
@Deprecated(since="17", forRemoval=true) public static <T> T doAsPrivileged(Subject subject, PrivilegedExceptionAction<T> action, AccessControlContext acc) throws PrivilegedActionException Deprecated, for removal: This API element is subject to removal in a future version.This method originally performed the specifiedPrivilegedExceptionAction
with privileges enabled and restricted by the specifiedAccessControlContext
. Running the action with privileges enabled was only useful in conjunction with the Security Manager, which is no longer supported. This method has been changed to ignore theAccessControlContext
and launch the action as is and bind the subject to the period of its execution. A replacement API namedcallAs(javax.security.auth.Subject, java.util.concurrent.Callable<T>)
has been added which can be used to perform the same work. There is no replacement for the Security Manager.Perform privileged work as a particularSubject
.This method launches
action
and bindssubject
to the period of its execution.- Type Parameters:
T
- the type of the value returned by the PrivilegedExceptionAction'srun
method.- Parameters:
subject
- theSubject
that the specifiedaction
will run as. This parameter may benull
.action
- the code to be run as the specifiedSubject
.acc
- ignored- Returns:
- the value returned by the
PrivilegedExceptionAction's
run
method. - Throws:
PrivilegedActionException
- if thePrivilegedExceptionAction.run
method throws a checked exception.NullPointerException
- if the specifiedPrivilegedExceptionAction
isnull
.- See Also:
-
getPrincipals
Return theSet
of Principals associated with thisSubject
. EachPrincipal
represents an identity for thisSubject
.The returned
Set
is backed by this Subject's internalPrincipal
Set
. Any modification to the returnedSet
affects the internalPrincipal
Set
as well.- Returns:
- the
Set
of Principals associated with thisSubject
.
-
getPrincipals
Return aSet
of Principals associated with thisSubject
that are instances or subclasses of the specifiedClass
.The returned
Set
is not backed by this Subject's internalPrincipal
Set
. A newSet
is created and returned for each method invocation. Modifications to the returnedSet
will not affect the internalPrincipal
Set
.- Type Parameters:
T
- the type of the class modeled byc
- Parameters:
c
- the returnedSet
of Principals will all be instances of this class.- Returns:
- a
Set
of Principals that are instances of the specifiedClass
. - Throws:
NullPointerException
- if the specifiedClass
isnull
.
-
getPublicCredentials
Return theSet
of public credentials held by thisSubject
.The returned
Set
is backed by this Subject's internal public CredentialSet
. Any modification to the returnedSet
affects the internal public CredentialSet
as well.- Returns:
- a
Set
of public credentials held by thisSubject
.
-
getPrivateCredentials
Return theSet
of private credentials held by thisSubject
.The returned
Set
is backed by this Subject's internal private CredentialSet
. Any modification to the returnedSet
affects the internal private CredentialSet
as well.- Returns:
- a
Set
of private credentials held by thisSubject
.
-
getPublicCredentials
Return aSet
of public credentials associated with thisSubject
that are instances or subclasses of the specifiedClass
.The returned
Set
is not backed by this Subject's internal public CredentialSet
. A newSet
is created and returned for each method invocation. Modifications to the returnedSet
will not affect the internal public CredentialSet
.- Type Parameters:
T
- the type of the class modeled byc
- Parameters:
c
- the returnedSet
of public credentials will all be instances of this class.- Returns:
- a
Set
of public credentials that are instances of the specifiedClass
. - Throws:
NullPointerException
- if the specifiedClass
isnull
.
-
getPrivateCredentials
Return aSet
of private credentials associated with thisSubject
that are instances or subclasses of the specifiedClass
.The returned
Set
is not backed by this Subject's internal private CredentialSet
. A newSet
is created and returned for each method invocation. Modifications to the returnedSet
will not affect the internal private CredentialSet
.- Type Parameters:
T
- the type of the class modeled byc
- Parameters:
c
- the returnedSet
of private credentials will all be instances of this class.- Returns:
- a
Set
of private credentials that are instances of the specifiedClass
. - Throws:
NullPointerException
- if the specifiedClass
isnull
.
-
equals
Compares the specified Object with thisSubject
for equality. Returns true if the given object is also a Subject and the twoSubject
instances are equivalent. More formally, twoSubject
instances are equal if theirPrincipal
andCredential
Sets are equal. -
toString
-
hashCode
-
PrivilegedAction
with privileges enabled.