org.argeo.util/src/org/argeo/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 evolution 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         private final static boolean useThreadLocal = Boolean
  19                         .parseBoolean(System.getProperty("jdk.security.auth.subject.useTL"));
  20
  21         private final static InheritableThreadLocal<Subject> current = new InheritableThreadLocal<>();
  22
  23         public static Subject current() {
  24                 if (useThreadLocal) {
  25                         return current.get();
  26                 } else {// legacy
  27                         Subject subject = Subject.getSubject(AccessController.getContext());
  28                         return subject;
  29                 }
  30         }
  31
  32         public static <T> T callAs(Subject subject, Callable<T> action) {
  33                 if (useThreadLocal) {
  34                         Subject previous = current();
  35                         current.set(subject);
  36                         try {
  37                                 return action.call();
  38                         } catch (Exception e) {
  39                                 throw new CompletionException("Failed to execute action for " + subject, e);
  40                         } finally {
  41                                 current.set(previous);
  42                         }
  43                 } else {// legacy
  44                         try {
  45                                 return Subject.doAs(subject, new PrivilegedExceptionAction<T>() {
  46
  47                                         @Override
  48                                         public T run() throws Exception {
  49                                                 return action.call();
  50                                         }
  51
  52                                 });
  53                         } catch (PrivilegedActionException e) {
  54                                 throw new CompletionException("Failed to execute action for " + subject, e.getCause());
  55                         } catch (Exception e) {
  56                                 throw new CompletionException("Failed to execute action for " + subject, e);
  57                         }
  58                 }
  59         }
  60
  61         /** Singleton. */
  62         private CurrentSubject() {
  63         }
  64
  65 }