cdmlib-persistence/src/main/java/eu/etaxonomy/cdm/persistence/validation/EntityValidationThread.java

   1 /**
   2 * Copyright (C) 2009 EDIT
   3 * European Distributed Institute of Taxonomy
   4 * http://www.e-taxonomy.eu
   5 *
   6 * The contents of this file are subject to the Mozilla Public License Version 1.1
   7 * See LICENSE.TXT at the top of this package for the full license terms.
   8 */
   9 package eu.etaxonomy.cdm.persistence.validation;
  10
  11 import javax.validation.ConstraintValidator;
  12 import javax.validation.Validator;
  13
  14 /**
  15  * A subclass of {@code Thread} specialized in running validation tasks. Each
  16  * {@code ValidationThread} has its own {@link Validator} instance. In addition it allows
  17  * a flag to be set (by the main thread) that the currently running
  18  * {@link ConstraintValidator} may query to see if there is a termination request. See
  19  * {@link ValidationExecutor} for the rationale behind this.
  20  *
  21  * @see {@link #isTerminationRequested()}.
  22  *
  23  * @author ayco holleman
  24  *
  25  */
  26 public final class EntityValidationThread extends Thread {
  27
  28         private final Validator validator;
  29
  30         private boolean terminationRequested;
  31         private EntityValidationTaskBase currentTask;
  32
  33
  34         EntityValidationThread(ThreadGroup group, Runnable runnable, String name, Validator validator)
  35         {
  36                 super(group, runnable, name);
  37                 this.validator = validator;
  38                 setPriority(MIN_PRIORITY);
  39         }
  40
  41
  42         /**
  43          * Flag indicating that the {@link ConstraintValidator} currently running in this
  44          * {@code ValidationThread} is requested to terminate itself. Constraint validators
  45          * can check whether to abort the validation like so:<br>
  46          * <code>
  47          * if(Thread.currentThread() instanceof ValidationThread) {
  48          *      ValidationThread vt = (ValidationThread) Thread.currentThread();
  49          *      if(vt.isTerminationRequested()) {
  50          *              // Stop with what I am doing
  51          *      }
  52          * }
  53          * </code>
  54          *
  55          * @return Whether or not the currently running {@link ConstraintValidator} is
  56          *         requested to terminate itself
  57          */
  58         public boolean isTerminationRequested()
  59         {
  60                 return terminationRequested;
  61         }
  62
  63
  64         void setTerminationRequested(boolean b)
  65         {
  66                 this.terminationRequested = b;
  67         }
  68
  69
  70         Validator getValidator()
  71         {
  72                 return validator;
  73         }
  74
  75
  76         EntityValidationTaskBase getCurrentTask()
  77         {
  78                 return currentTask;
  79         }
  80
  81
  82         void setCurrentTask(EntityValidationTaskBase currentTask)
  83         {
  84                 this.currentTask = currentTask;
  85         }
  86
  87 }