util/CurrentSubject.java

   1 package org.argeo.util;
   2
   3 import java.security.AccessController;
   4 import java.security.PrivilegedActionException;
   5 import java.security.PrivilegedExceptionAction;
   6 import java.util.concurrent.Callable;
   7 import java.util.concurrent.CompletionException;
   8
   9 import javax.security.auth.Subject;
  10
  11 /**
  12  * Prepare evotion of Java APIs introduced in JDK 18, as these static methods
  13  * will be added to {@link Subject}.
  14  */
  15 @SuppressWarnings("removal")
  16 public class CurrentSubject {
  17
  18         /** Singleton. */
  19         private CurrentSubject() {
  20
  21         }
  22
  23         public static Subject current() {
  24                 Subject subject = Subject.getSubject(AccessController.getContext());
  25                 if (subject == null)
  26                         throw new IllegalStateException("Cannot find related subject");
  27                 return subject;
  28         }
  29
  30         public static <T> T callAs(Subject subject, Callable<T> action) {
  31                 try {
  32                         return Subject.doAs(subject, new PrivilegedExceptionAction<T>() {
  33
  34                                 @Override
  35                                 public T run() throws Exception {
  36                                         return action.call();
  37                                 }
  38
  39                         });
  40                 } catch (PrivilegedActionException e) {
  41                         throw new CompletionException("Failed to execute action for " + subject, e.getCause());
  42                 }
  43         }
  44 }