objectoutputstream.java

gcc的组建

	realOutput.writeByte(TC_RESET);
      }
    
    clearHandles();
  }


  /**
   * Informs this <code>ObjectOutputStream</code> to write data
   * according to the specified protocol.  There are currently two
   * different protocols, specified by <code>PROTOCOL_VERSION_1</code>
   * and <code>PROTOCOL_VERSION_2</code>.  This implementation writes
   * data using <code>PROTOCOL_VERSION_2</code> by default, as is done
   * by the JDK 1.2.
   *
   * A non-portable method, <code>setDefaultProtocolVersion (int
   * version)</code> is provided to change the default protocol
   * version.
   *
   * For an explanation of the differences between the two protocols
   * see XXX: the Java ObjectSerialization Specification.
   *
   * @exception IOException if <code>version</code> is not a valid
   * protocol
   *
   * @see #setDefaultProtocolVersion(int)
   */
  public void useProtocolVersion(int version) throws IOException
  {
    if (version != PROTOCOL_VERSION_1 && version != PROTOCOL_VERSION_2)
      throw new IOException("Invalid protocol version requested.");
    
    protocolVersion = version;
  }


  /**
   * <em>GNU $classpath specific</em>
   *
   * Changes the default stream protocol used by all
   * <code>ObjectOutputStream</code>s.  There are currently two
   * different protocols, specified by <code>PROTOCOL_VERSION_1</code>
   * and <code>PROTOCOL_VERSION_2</code>.  The default default is
   * <code>PROTOCOL_VERSION_1</code>.
   *
   * @exception IOException if <code>version</code> is not a valid
   * protocol
   *
   * @see #useProtocolVersion(int)
   */
  public static void setDefaultProtocolVersion(int version)
    throws IOException
  {
    if (version != PROTOCOL_VERSION_1 && version != PROTOCOL_VERSION_2)
      throw new IOException("Invalid protocol version requested.");

    defaultProtocolVersion = version;
  }


  /**
   * An empty hook that allows subclasses to write extra information
   * about classes to the stream.  This method is called the first
   * time each class is seen, and after all of the standard
   * information about the class has been written.
   *
   * @exception IOException Exception from underlying
   * <code>OutputStream</code>.
   *
   * @see ObjectInputStream#resolveClass(java.io.ObjectStreamClass)
   */
  protected void annotateClass(Class cl) throws IOException
  {
  }

  protected void annotateProxyClass(Class cl) throws IOException
  {
  }

  /**
   * Allows subclasses to replace objects that are written to the
   * stream with other objects to be written in their place.  This
   * method is called the first time each object is encountered
   * (modulo reseting of the stream).
   *
   * This method must be enabled before it will be called in the
   * serialization process.
   *
   * @exception IOException Exception from underlying
   * <code>OutputStream</code>.
   *
   * @see #enableReplaceObject(boolean)
   */
  protected Object replaceObject(Object obj) throws IOException
  {
    return obj;
  }


  /**
   * If <code>enable</code> is <code>true</code> and this object is
   * trusted, then <code>replaceObject (Object)</code> will be called
   * in subsequent calls to <code>writeObject (Object)</code>.
   * Otherwise, <code>replaceObject (Object)</code> will not be called.
   *
   * @exception SecurityException This class is not trusted.
   */
  protected boolean enableReplaceObject(boolean enable)
    throws SecurityException
  {
    if (enable)
      {
	SecurityManager sm = System.getSecurityManager();
	if (sm != null)
	  sm.checkPermission(new SerializablePermission("enableSubstitution"));
      }

    boolean old_val = replacementEnabled;
    replacementEnabled = enable;
    return old_val;
  }


  /**
   * Writes stream magic and stream version information to the
   * underlying stream.
   *
   * @exception IOException Exception from underlying
   * <code>OutputStream</code>.
   */
  protected void writeStreamHeader() throws IOException
  {
    realOutput.writeShort(STREAM_MAGIC);
    realOutput.writeShort(STREAM_VERSION);
  }

  /**
   * Protected constructor that allows subclasses to override
   * serialization.  This constructor should be called by subclasses
   * that wish to override <code>writeObject (Object)</code>.  This
   * method does a security check <i>NOTE: currently not
   * implemented</i>, then sets a flag that informs
   * <code>writeObject (Object)</code> to call the subclasses
   * <code>writeObjectOverride (Object)</code> method.
   *
   * @see #writeObjectOverride(Object)
   */
  protected ObjectOutputStream() throws IOException, SecurityException
  {
    SecurityManager sec_man = System.getSecurityManager ();
    if (sec_man != null)
      sec_man.checkPermission(SUBCLASS_IMPLEMENTATION_PERMISSION);
    useSubclassMethod = true;
  }


  /**
   * This method allows subclasses to override the default
   * serialization mechanism provided by
   * <code>ObjectOutputStream</code>.  To make this method be used for
   * writing objects, subclasses must invoke the 0-argument
   * constructor on this class from there constructor.
   *
   * @see #ObjectOutputStream()
   *
   * @exception NotActiveException Subclass has arranged for this
   * method to be called, but did not implement this method.
   */
  protected void writeObjectOverride(Object obj) throws NotActiveException,
    IOException
  {
    throw new NotActiveException
      ("Subclass of ObjectOutputStream must implement writeObjectOverride");
  }


  /**
   * @see DataOutputStream#write(int)
   */
  public void write (int data) throws IOException
  {
    if (writeDataAsBlocks)
      {
	if (blockDataCount == BUFFER_SIZE)
	  drain();

	blockData[ blockDataCount++ ] = (byte)data;
      }
    else
      realOutput.write(data);
  }


  /**
   * @see DataOutputStream#write(byte[])
   */
  public void write(byte[] b) throws IOException
  {
    write(b, 0, b.length);
  }


  /**
   * @see DataOutputStream#write(byte[],int,int)
   */
  public void write(byte[] b, int off, int len) throws IOException
  {
    if (writeDataAsBlocks)
      {
	if (len < 0)
	  throw new IndexOutOfBoundsException();

	if (blockDataCount + len < BUFFER_SIZE)
	  {
	    System.arraycopy(b, off, blockData, blockDataCount, len);
	    blockDataCount += len;
	  }
	else
	  {
	    drain();
	    writeBlockDataHeader(len);
	    realOutput.write(b, off, len);
	  }
      }
    else
      realOutput.write(b, off, len);
  }


  /**
   * @see DataOutputStream#flush()
   */
  public void flush () throws IOException
  {
    drain();
    realOutput.flush();
  }


  /**
   * Causes the block-data buffer to be written to the underlying
   * stream, but does not flush underlying stream.
   *
   * @exception IOException Exception from underlying
   * <code>OutputStream</code>.
   */
  protected void drain() throws IOException
  {
    if (blockDataCount == 0)
      return;

    if (writeDataAsBlocks)
      writeBlockDataHeader(blockDataCount);
    realOutput.write(blockData, 0, blockDataCount);
    blockDataCount = 0;
  }


  /**
   * @see java.io.DataOutputStream#close ()
   */
  public void close() throws IOException
  {
    flush();
    realOutput.close();
  }


  /**
   * @see java.io.DataOutputStream#writeBoolean (boolean)
   */
  public void writeBoolean(boolean data) throws IOException
  {
    blockDataOutput.writeBoolean(data);
  }


  /**
   * @see java.io.DataOutputStream#writeByte (int)
   */
  public void writeByte(int data) throws IOException
  {
    blockDataOutput.writeByte(data);
  }


  /**
   * @see java.io.DataOutputStream#writeShort (int)
   */
  public void writeShort (int data) throws IOException
  {
    blockDataOutput.writeShort(data);
  }


  /**
   * @see java.io.DataOutputStream#writeChar (int)
   */
  public void writeChar(int data) throws IOException
  {
    blockDataOutput.writeChar(data);
  }


  /**
   * @see java.io.DataOutputStream#writeInt (int)
   */
  public void writeInt(int data) throws IOException
  {
    blockDataOutput.writeInt(data);
  }


  /**
   * @see java.io.DataOutputStream#writeLong (long)
   */
  public void writeLong(long data) throws IOException
  {
    blockDataOutput.writeLong(data);
  }


  /**
   * @see java.io.DataOutputStream#writeFloat (float)
   */
  public void writeFloat(float data) throws IOException
  {
    blockDataOutput.writeFloat(data);
  }


  /**
   * @see java.io.DataOutputStream#writeDouble (double)
   */
  public void writeDouble(double data) throws IOException
  {
    blockDataOutput.writeDouble(data);
  }


  /**
   * @see java.io.DataOutputStream#writeBytes (java.lang.String)
   */
  public void writeBytes(String data) throws IOException
  {
    blockDataOutput.writeBytes(data);
  }


  /**
   * @see java.io.DataOutputStream#writeChars (java.lang.String)
   */
  public void writeChars(String data) throws IOException
  {
    dataOutput.writeChars(data);
  }


  /**
   * @see java.io.DataOutputStream#writeUTF (java.lang.String)
   */
  public void writeUTF(String data) throws IOException
  {
    dataOutput.writeUTF(data);
  }


  /**
   * This class allows a class to specify exactly which fields should
   * be written, and what values should be written for these fields.
   *
   * XXX: finish up comments
   */
  public abstract static class PutField
  {
    public abstract void put (String name, boolean value);
    public abstract void put (String name, byte value);
    public abstract void put (String name, char value);
    public abstract void put (String name, double value);
    public abstract void put (String name, float value);
    public abstract void put (String name, int value);
    public abstract void put (String name, long value);
    public abstract void put (String name, short value);
    public abstract void put (String name, Object value);

    /**
     * @deprecated
     */
    public abstract void write (ObjectOutput out) throws IOException;
  }

  public PutField putFields() throws IOException
  {
    if (currentPutField != null)
      return currentPutField;

    currentPutField = new PutField()
      {
	private byte[] prim_field_data
	  = new byte[currentObjectStreamClass.primFieldSize];
	private Object[] objs
	  = new Object[currentObjectStreamClass.objectFieldCount];

	private ObjectStreamField getField (String name)
	{
	  ObjectStreamField field
	    = currentObjectStreamClass.getField(name);
	  
	  if (field == null)
	    throw new IllegalArgumentException("no such serializable field " + name);
	  
	  return field;
	}
	
	public void put(String name, boolean value)
	{
	  ObjectStreamField field = getField(name);

	  checkType(field, 'Z');
	  prim_field_data[field.getOffset ()] = (byte)(value ? 1 : 0);
	}

	public void put(String name, byte value)
	{
	  ObjectStreamField field = getField(name);

	  checkType(field, 'B');
	  prim_field_data[field.getOffset()] = value;
	}

	public void put(String name, char value)
	{
	  ObjectStreamField field = getField(name);

	  checkType(field, 'C');
	  int off = field.getOffset();
	  prim_field_data[off++] = (byte)(value >>> 8);
	  prim_field_data[off] = (byte)value;
	}

	public void put(String name, double value)
	{
	  ObjectStreamField field = getField (name);

	  checkType(field, 'D');
	  int off = field.getOffset();
	  long l_value = Double.doubleToLongBits (value);
	  prim_field_data[off++] = (byte)(l_value >>> 52);
	  prim_field_data[off++] = (byte)(l_value >>> 48);
	  prim_field_data[off++] = (byte)(l_value >>> 40);
	  prim_field_data[off++] = (byte)(l_value >>> 32);
	  prim_field_data[off++] = (byte)(l_value >>> 24);
	  prim_field_data[off++] = (byte)(l_value >>> 16);
	  prim_field_data[off++] = (byte)(l_value >>> 8);
	  prim_field_data[off] = (byte)l_value;
	}

	public void put(String name, float value)
	{
	  ObjectStreamField field = getField(name);

	  checkType(field, 'F');
	  int off = field.getOffset();
	  int i_value = Float.floatToIntBits(value);
	  prim_field_data[off++] = (byte)(i_value >>> 24);
	  prim_field_data[off++] = (byte)(i_value >>> 16);
	  prim_field_data[off++] = (byte)(i_value >>> 8);
	  prim_field_data[off] = (byte)i_value;
	}

	public void put(String name, int value)
	{
	  ObjectStreamField field = getField(name);
	  checkType(field, 'I');
	  int off = field.getOffset();
	  prim_field_data[off++] = (byte)(value >>> 24);
	  prim_field_data[off++] = (byte)(value >>> 16);
	  prim_field_data[off++] = (byte)(value >>> 8);
	  prim_field_data[off] = (byte)value;
	}

	public void put(String name, long value)
	{
	  ObjectStreamField field = getField(name);
	  checkType(field, 'J');
	  int off = field.getOffset();
	  prim_field_data[off++] = (byte)(value >>> 52);
	  prim_field_data[off++] = (byte)(value >>> 48);
	  prim_field_data[off++] = (byte)(value >>> 40);
	  prim_field_data[off++] = (byte)(value >>> 32);
	  prim_field_data[off++] = (byte)(value >>> 24);
	  prim_field_data[off++] = (byte)(value >>> 16);
	  prim_field_data[off++] = (byte)(value >>> 8);
	  prim_field_data[off] = (byte)value;
	}

	public void put(String name, short value)
	{
	  ObjectStreamField field = getField(name);
	  checkType(field, 'S');
	  int off = field.getOffset();
	  prim_field_data[off++] = (byte)(value >>> 8);
	  prim_field_data[off] = (byte)value;
	}

	public void put(String name, Object value)
	{
	  ObjectStreamField field = getField(name);

	  if (value != null &&
	      ! field.getType().isAssignableFrom(value.getClass ()))	    
	    throw new IllegalArgumentException("Class " + value.getClass() +
					       " cannot be cast to " + field.getType());
	  objs[field.getOffset()] = value;
	}

	public void write(ObjectOutput out) throws IOException
	{
	  // Apparently Block data is not used with PutField as per
	  // empirical evidence against JDK 1.2.  Also see Mauve test
	  // java.io.ObjectInputOutput.Test.GetPutField.
	  boolean oldmode = setBlockDataMode(false);
	  out.write(prim_field_data);
	  for (int i = 0; i < objs.length; ++ i)
	    out.writeObject(objs[i]);
	  setBlockDataMode(oldmode);
	}

	private void checkType(ObjectStreamField field, char type)