com.sleepycat.bind.serial
Class SerialOutput

java.lang.Object
  java.io.OutputStream
      java.io.ObjectOutputStream
          com.sleepycat.bind.serial.SerialOutput

All Implemented Interfaces:

Closeable, DataOutput, Flushable, ObjectOutput, ObjectStreamConstants

public class SerialOutput
extends ObjectOutputStream

A specialized ObjectOutputStream that stores class description information in a ClassCatalog. It is used by SerialBinding.

This class is used instead of an ObjectOutputStream, which it extends, to write a compact object stream. For writing objects to a database normally one of the serial binding classes is used. SerialOutput is used when an ObjectOutputStream is needed along with compact storage. A ClassCatalog must be supplied, however, to stored shared class descriptions.

The ClassCatalog is used to store class definitions rather than embedding these into the stream. Instead, a class format identifier is embedded into the stream. This identifier is then used by SerialInput to load the class format to deserialize the object.

See Also:

Class Evolution

Nested Class Summary

Nested classes/interfaces inherited from class java.io.ObjectOutputStream

ObjectOutputStream.PutField

Field Summary

Fields inherited from interface java.io.ObjectStreamConstants

baseWireHandle, PROTOCOL_VERSION_1, PROTOCOL_VERSION_2, SC_BLOCK_DATA, SC_ENUM, SC_EXTERNALIZABLE, SC_SERIALIZABLE, SC_WRITE_METHOD, STREAM_MAGIC, STREAM_VERSION, SUBCLASS_IMPLEMENTATION_PERMISSION, SUBSTITUTION_PERMISSION, TC_ARRAY, TC_BASE, TC_BLOCKDATA, TC_BLOCKDATALONG, TC_CLASS, TC_CLASSDESC, TC_ENDBLOCKDATA, TC_ENUM, TC_EXCEPTION, TC_LONGSTRING, TC_MAX, TC_NULL, TC_OBJECT, TC_PROXYCLASSDESC, TC_REFERENCE, TC_RESET, TC_STRING

Constructor Summary

SerialOutput(OutputStream out, ClassCatalog classCatalog)
Creates a serial output stream.

Method Summary

static byte[]	getStreamHeader() Returns the fixed stream header used for all serialized streams in PROTOCOL_VERSION_2 format.
protected void	writeClassDescriptor(ObjectStreamClass classdesc)

Methods inherited from class java.io.ObjectOutputStream

annotateClass, annotateProxyClass, close, defaultWriteObject, drain, enableReplaceObject, flush, putFields, replaceObject, reset, useProtocolVersion, write, write, write, writeBoolean, writeByte, writeBytes, writeChar, writeChars, writeDouble, writeFields, writeFloat, writeInt, writeLong, writeObject, writeObjectOverride, writeShort, writeStreamHeader, writeUnshared, writeUTF

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

SerialOutput

public SerialOutput(OutputStream out,
                    ClassCatalog classCatalog)
             throws IOException

Creates a serial output stream.

Parameters:

out - is the output stream to which the compact serialized objects will be written.

classCatalog - is the catalog to which the class descriptions for the serialized objects will be written.

Throws:

IOException

Method Detail

writeClassDescriptor

protected void writeClassDescriptor(ObjectStreamClass classdesc)
                             throws IOException

Overrides:

writeClassDescriptor in class ObjectOutputStream

Throws:

IOException

getStreamHeader

public static byte[] getStreamHeader()

Returns the fixed stream header used for all serialized streams in PROTOCOL_VERSION_2 format. To save space this header can be removed and serialized streams before storage and inserted before deserializing. SerialOutput always uses PROTOCOL_VERSION_2 serialization format to guarantee that this header is fixed. SerialBinding removes this header from serialized streams automatically.

Returns:

the fixed stream header.