org.apache.hadoop.security.authentication.util

Class SubjectUtil

java.lang.Object

org.apache.hadoop.security.authentication.util.SubjectUtil

@InterfaceAudience.Private
public final class SubjectUtil
extends Object

An utility class that adapts the Security Manager and APIs related to it for JDK 8 and above.

In JDK 17, the Security Manager and APIs related to it have been deprecated and are subject to removal in a future release. There is no replacement for the Security Manager. See JEP 411 for discussion and alternatives.

In JDK 24, the Security Manager has been permanently disabled. See JEP 486 for more information.

This is derived from Apache Calcite Avatica, which is derived from the Jetty implementation.

Method Summary

Modifier and Type	Method and Description
static <T> T	callAs(Subject subject, Callable<T> action) Map to Subject.callAs() if available, otherwise maps to Subject.doAs().
static Subject	current() Maps to Subject.current() if available, otherwise maps to Subject.getSubject().
static <T> T	doAs(Subject subject, PrivilegedAction<T> action) Map action to a Callable on Java 18 onwards, and delegates to callAs().
static <T> T	doAs(Subject subject, PrivilegedExceptionAction<T> action) Maps action to a Callable on Java 18 onwards, and delegates to callAs().

Methods inherited from class java.lang.Object

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

Method Detail

callAs

public static <T> T callAs(Subject subject,
                           Callable<T> action)
                    throws CompletionException

Map to Subject.callAs() if available, otherwise maps to Subject.doAs().

Type Parameters:

T - the type of the result

Parameters:

subject - the subject this action runs as

action - the action to run

Returns:

the result of the action

Throws:

NullPointerException - if action is null

CompletionException - if action.call() throws an exception. The cause of the CompletionException is set to the exception thrown by action.call().

doAs

public static <T> T doAs(Subject subject,
                         PrivilegedAction<T> action)

Map action to a Callable on Java 18 onwards, and delegates to callAs(). Call Subject.doAs directly on older JVM.

Note: Exception propagation behavior is different since Java 12, it always throw the original exception thrown by action; for lower Java versions, throw a PrivilegedActionException that wraps the original exception when action throw a checked exception.

Type Parameters:

T - the type of the result

Parameters:

subject - the subject this action runs as

action - the action to run

Returns:

the result of the action

Throws:

NullPointerException - if action is null

doAs

public static <T> T doAs(Subject subject,
                         PrivilegedExceptionAction<T> action)
                  throws PrivilegedActionException

Maps action to a Callable on Java 18 onwards, and delegates to callAs(). Call Subject.doAs directly on older JVM.

Type Parameters:

T - the type of the result

Parameters:

subject - the subject this action runs as

action - the action to run

Returns:

the result of the action

Throws:

NullPointerException - if action is null

PrivilegedActionException - if action.run() throws an checked exception. The cause of the PrivilegedActionException is set to the exception thrown by action.run().

current

public static Subject current()

Maps to Subject.current() if available, otherwise maps to Subject.getSubject().

Returns:

the current subject