1   /*

     2    * %W% %E%

     3    *

     4    * Copyright (c) 2006, 2010  Oracle and/or its affiliates. All rights reserved.

     5    * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.

     6    */

     7 

     8   package java.io;

     9 

    10   /**

    11    * Context during upcalls from object stream to class-defined

    12    * readObject/writeObject methods.

    13    * Holds object currently being deserialized and descriptor for current class.

    14    *

    15    * This context keeps track of the thread it was constructed on, and allows

    16    * only a single call of defaultReadObject, readFields, defaultWriteObject

    17    * or writeFields which must be invoked on the same thread before the class's

    18    * readObject/writeObject method has returned.

    19    * If not set to the current thread, the getObj method throws NotActiveException.

    20    */

    21   final class SerialCallbackContext {

    22       private final Object obj;

    23       private final ObjectStreamClass desc;

    24       /**

    25        * Thread this context is in use by.

    26        * As this only works in one thread, we do not need to worry about thread-safety.

    27        */

    28       private Thread thread;

    29 

    30       public SerialCallbackContext(Object obj, ObjectStreamClass desc) {

    31           this.obj = obj;

    32           this.desc = desc;

    33           this.thread = Thread.currentThread();

    34       }

    35 

    36       public Object getObj() throws NotActiveException {

    37           checkAndSetUsed();

    38           return obj;

    39       }

    40 

    41       public ObjectStreamClass getDesc() {

    42           return desc;

    43       }

    44 

    45       private void checkAndSetUsed() throws NotActiveException {

    46           if (thread != Thread.currentThread()) {

    47                throw new NotActiveException(

    48                 "not in readObject invocation or fields already read");

    49           }

    50           thread = null;

    51       }

    52 

    53       public void setUsed() {

    54           thread = null;

    55       }

    56   }

    57 

    58