org.metasyntactic.io
Class XMLOutputStream

java.lang.Object
  |
  +--java.io.OutputStream
        |
        +--java.io.ObjectOutputStream
              |
              +--org.metasyntactic.io.XMLOutputStream

All Implemented Interfaces:

java.io.DataOutput, java.io.ObjectOutput, java.io.ObjectStreamConstants, XMLStreamConstants

public class XMLOutputStream

extends java.io.ObjectOutputStream

implements XMLStreamConstants

An XMLOutputStream writes primitive data types and graphs of Java objects to an OutputStream as well-formed, valid XML. Included in the DOCTYPE is a reference to Stream.dtd. This DTD is not necessary, but does allow a XML Parser to make sure that the XML was not damaged in a valid-breaking manner.

The objects can be read (reconstituted) using an XMLInputStream. Persistent storage of objects can be accomplished by using a file for the stream. If the stream is a network socket stream, the objects can be reconsituted on another host or in another process.

Only objects that support the java.io.Serializable interface can be written to streams. The class of each serializable object is encoded including the class name and signature of the class, the values of the object's fields and arrays, and the closure of any other objects referenced from the initial objects.

The method writeObject is used to write an object to the stream. Any object, including Strings and arrays, is written with writeObject. Multiple objects or primitives can be written to the stream. The objects must be read back from the corresponding XMLInputstream with the same types and in the same order as they were written.

Primitive data types can also be written to the stream using the appropriate methods from DataOutput.

The default serialization mechanism for an object writes the class of the object, the class signature, and the values of all non-transient and non-static fields. References to other objects (except in transient or static fields) cause those objects to be written also. Multiple references to a single object are encoded using a reference sharing mechanism so that graphs of objects can be restored to the same shape as when the original was written. Classes that require special handling during the serialization and deserialization process must implement special methods with these exact signatures:

 private void readObject(java.io.ObjectInputStream stream)
    throws IOException, ClassNotFoundException;
 private void writeObject(java.io.ObjectOutputStream stream)
    throws IOException
 

The writeObject method is responsible for writing the state of the object for its particular class so that the corresponding readObject method can restore it. The method does not need to concern itself with the state belonging to the object's superclasses or subclasses. State is saved by writing the individual fields to the XMLOutputStream using the writeObject method or by using the methods for primitive data types supported by DataOutput.

Serialization does not write out the fields of any object that does not implement the java.io.Serializable interface. Subclasses of Objects that are not serializable can be serializable. In this case the non-serializable class must have a no-arg constructor to allow its fields to be initialized. In this case it is the responsibility of the subclass to save and restore the state of the non-serializable class. It is frequently the case that the fields of that class are accessible (public, package, or protected) or that there are get and set methods that can be used to restore the state.

Nested Class Summary

Nested classes inherited from class java.io.ObjectOutputStream

java.io.ObjectOutputStream.PutField

Field Summary

protected org.w3c.dom.Node	currentNode
protected org.w3c.dom.Document	document
protected DOMSerializer	domSerializer
protected static java.lang.Class[]	EMPTY_CLASS_ARRAY
protected static java.lang.Object[]	EMPTY_OBJECT_ARRAY
protected HandleTable	handleTable
protected int	nextReplaceOffset
protected java.io.PrintStream	out
protected java.lang.Object[]	replaceObjects
static java.lang.String	VERSION
static java.lang.String	VERSION_STRING
protected static java.lang.Class[]	WRITE_OBJECT_ARGS

Fields inherited from interface org.metasyntactic.io.XMLStreamConstants

ARRAY_ELEMENT, CLASS_DESCRIPTOR_ELEMENT, CLASS_ELEMENT, FIELD_ELEMENT, FIELDS_ELEMENT, ID_ATTRIBUTE, IDREF_ATTRIBUTE, LENGTH_ATTRIBUTE, NAME_ATTRIBUTE, NAME_SPACE_URI, NULL_ELEMENT, OBJECT_ELEMENT, PRIMITIVE_ARRAY_ELEMENT_SEPARATOR, PRIMITIVE_ELEMENT, REFERENCE_ELEMENT, RESET_ELEMENT, SERIAL_VERSION_UID_ATTRIBUTE, STREAM_ELEMENT, STRING_ELEMENT, TYPE_ATTRIBUTE, VALUE_ATTRIBUTE, VERSION_ATTRIBUTE

Fields inherited from interface java.io.ObjectStreamConstants

baseWireHandle, PROTOCOL_VERSION_1, PROTOCOL_VERSION_2, SC_BLOCK_DATA, 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_EXCEPTION, TC_LONGSTRING, TC_MAX, TC_NULL, TC_OBJECT, TC_PROXYCLASSDESC, TC_REFERENCE, TC_RESET, TC_STRING

Constructor Summary

XMLOutputStream(java.io.OutputStream out)

XMLOutputStream(java.io.OutputStream out, boolean indent)

Method Summary

protected void	addReplacement(java.lang.Object orig, java.lang.Object replacement)
void	close()
protected void	defaultWriteObject(java.lang.Object obj, ClassDescriptor currentClassDesc)
void	flush()
org.w3c.dom.Document	getDocument()
protected boolean	hasWriteObjectMethod(ClassDescriptor desc)
protected void	invokeObjectWriter(java.lang.Object obj, ClassDescriptor desc)
static void	main(java.lang.String[] args)
protected void	outputClassFields(java.lang.Object obj, java.lang.Class clazz, java.lang.reflect.Field[] fields)
protected int	previouslyReplaced(java.lang.Object o)
protected int	previouslyWritten(java.lang.Object o)
void	reset()
protected org.w3c.dom.Element	resetInternal()
void	write(byte[] b)
void	write(byte[] b, int off, int len)
void	write(int b)
void	writeBoolean(boolean v)
protected org.w3c.dom.Element	writeBooleanInternal(boolean v)
void	writeByte(int v)
protected org.w3c.dom.Element	writeByteInternal(int v)
void	writeBytes(java.lang.String s)
void	writeChar(char v)
void	writeChar(long v)
protected org.w3c.dom.Element	writeCharInternal(char v)
void	writeChars(java.lang.String s)
protected org.w3c.dom.Element	writeClassDescriptor(ClassDescriptor desc)
void	writeDouble(double v)
protected org.w3c.dom.Element	writeDoubleInternal(double v)
protected void	writeFieldDescriptor(java.lang.reflect.Field field)
protected void	writeFields(java.lang.reflect.Field[] fields)
void	writeFloat(float v)
protected org.w3c.dom.Element	writeFloatInternal(float v)
void	writeInt(int v)
protected org.w3c.dom.Element	writeIntInternal(int v)
void	writeLong(long v)
protected org.w3c.dom.Element	writeLongInternal(long v)
protected org.w3c.dom.Element	writeNewArray(java.lang.Object array)
protected org.w3c.dom.Element	writeNewClass(java.lang.Class clazz)
protected org.w3c.dom.Element	writeNewClassDescriptor(ClassDescriptor desc)
protected org.w3c.dom.Element	writeNewObject(java.lang.Object obj)
protected org.w3c.dom.Element	writeNewString(java.lang.String string)
protected org.w3c.dom.Element	writeNull(java.lang.Object o)
protected org.w3c.dom.Element	writeNullOrReferenceToRepeat(java.lang.Object obj)
protected org.w3c.dom.Element	writeObjectInternal(java.lang.Object obj)
protected void	writeObjectOverride(java.lang.Object obj)
protected org.w3c.dom.Element	writeReference(int handle)
void	writeShort(short v)
protected org.w3c.dom.Element	writeShortInternal(int v)
protected void	writeSuperclassDescriptor(ClassDescriptor desc)
void	writeUTF(java.lang.String str)

Methods inherited from class java.io.ObjectOutputStream

annotateClass, annotateProxyClass, defaultWriteObject, drain, enableReplaceObject, putFields, replaceObject, useProtocolVersion, writeChar, writeClassDescriptor, writeFields, writeObject, writeShort, writeStreamHeader, writeUnshared

Methods inherited from class java.lang.Object

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

Field Detail

handleTable

protected final HandleTable handleTable

document

protected final org.w3c.dom.Document document

currentNode

protected org.w3c.dom.Node currentNode

out

protected final java.io.PrintStream out

domSerializer

protected final DOMSerializer domSerializer

VERSION

public static final java.lang.String VERSION

See Also:

Constant Field Values

VERSION_STRING

public static final java.lang.String VERSION_STRING

See Also:

Constant Field Values

EMPTY_CLASS_ARRAY

protected static final java.lang.Class[] EMPTY_CLASS_ARRAY

EMPTY_OBJECT_ARRAY

protected static final java.lang.Object[] EMPTY_OBJECT_ARRAY

replaceObjects

protected java.lang.Object[] replaceObjects

nextReplaceOffset

protected int nextReplaceOffset

WRITE_OBJECT_ARGS

protected static final java.lang.Class[] WRITE_OBJECT_ARGS

Constructor Detail

XMLOutputStream

public XMLOutputStream(java.io.OutputStream out)
                throws java.io.IOException

XMLOutputStream

public XMLOutputStream(java.io.OutputStream out,
                       boolean indent)
                throws java.io.IOException

Method Detail

getDocument

public org.w3c.dom.Document getDocument()

writeUTF

public void writeUTF(java.lang.String str)
              throws java.io.IOException

Specified by:

writeUTF in interface java.io.DataOutput

Overrides:

writeUTF in class java.io.ObjectOutputStream

java.io.IOException

writeChars

public void writeChars(java.lang.String s)
                throws java.io.IOException

Specified by:

writeChars in interface java.io.DataOutput

Overrides:

writeChars in class java.io.ObjectOutputStream

java.io.IOException

writeBytes

public void writeBytes(java.lang.String s)
                throws java.io.IOException

Specified by:

writeBytes in interface java.io.DataOutput

Overrides:

writeBytes in class java.io.ObjectOutputStream

java.io.IOException

writeDouble

public void writeDouble(double v)
                 throws java.io.IOException

Specified by:

writeDouble in interface java.io.DataOutput

Overrides:

writeDouble in class java.io.ObjectOutputStream

java.io.IOException

writeDoubleInternal

protected org.w3c.dom.Element writeDoubleInternal(double v)
                                           throws java.io.IOException

java.io.IOException

writeFloat

public void writeFloat(float v)
                throws java.io.IOException

Specified by:

writeFloat in interface java.io.DataOutput

Overrides:

writeFloat in class java.io.ObjectOutputStream

java.io.IOException

writeFloatInternal

protected org.w3c.dom.Element writeFloatInternal(float v)
                                          throws java.io.IOException

java.io.IOException

writeLong

public void writeLong(long v)
               throws java.io.IOException

Specified by:

writeLong in interface java.io.DataOutput

Overrides:

writeLong in class java.io.ObjectOutputStream

java.io.IOException

writeLongInternal

protected org.w3c.dom.Element writeLongInternal(long v)
                                         throws java.io.IOException

java.io.IOException

writeInt

public void writeInt(int v)
              throws java.io.IOException

Specified by:

writeInt in interface java.io.DataOutput

Overrides:

writeInt in class java.io.ObjectOutputStream

java.io.IOException

writeIntInternal

protected org.w3c.dom.Element writeIntInternal(int v)
                                        throws java.io.IOException

java.io.IOException

writeChar

public void writeChar(long v)

writeChar

public void writeChar(char v)
               throws java.io.IOException

java.io.IOException

writeCharInternal

protected org.w3c.dom.Element writeCharInternal(char v)
                                         throws java.io.IOException

java.io.IOException

writeShort

public void writeShort(short v)
                throws java.io.IOException

java.io.IOException

writeShortInternal

protected org.w3c.dom.Element writeShortInternal(int v)
                                          throws java.io.IOException

java.io.IOException

writeByte

public void writeByte(int v)
               throws java.io.IOException

Specified by:

writeByte in interface java.io.DataOutput

Overrides:

writeByte in class java.io.ObjectOutputStream

java.io.IOException

writeByteInternal

protected org.w3c.dom.Element writeByteInternal(int v)
                                         throws java.io.IOException

java.io.IOException

writeBoolean

public void writeBoolean(boolean v)
                  throws java.io.IOException

Specified by:

writeBoolean in interface java.io.DataOutput

Overrides:

writeBoolean in class java.io.ObjectOutputStream

java.io.IOException

writeBooleanInternal

protected org.w3c.dom.Element writeBooleanInternal(boolean v)
                                            throws java.io.IOException

java.io.IOException

close

public void close()
           throws java.io.IOException

Specified by:

close in interface java.io.ObjectOutput

Overrides:

close in class java.io.ObjectOutputStream

java.io.IOException

flush

public void flush()
           throws java.io.IOException

Specified by:

flush in interface java.io.ObjectOutput

Overrides:

flush in class java.io.ObjectOutputStream

java.io.IOException

reset

public void reset()
           throws java.io.IOException

Overrides:

reset in class java.io.ObjectOutputStream

java.io.IOException

resetInternal

protected org.w3c.dom.Element resetInternal()

write

public void write(byte[] b,
                  int off,
                  int len)
           throws java.io.IOException

Specified by:

write in interface java.io.ObjectOutput

Overrides:

write in class java.io.ObjectOutputStream

java.io.IOException

write

public void write(byte[] b)
           throws java.io.IOException

Specified by:

write in interface java.io.ObjectOutput

Overrides:

write in class java.io.ObjectOutputStream

java.io.IOException

write

public void write(int b)
           throws java.io.IOException

Specified by:

write in interface java.io.ObjectOutput

Overrides:

write in class java.io.ObjectOutputStream

java.io.IOException

writeNullOrReferenceToRepeat

protected org.w3c.dom.Element writeNullOrReferenceToRepeat(java.lang.Object obj)
                                                    throws java.io.IOException

java.io.IOException

writeReference

protected org.w3c.dom.Element writeReference(int handle)
                                      throws java.io.IOException

java.io.IOException

previouslyReplaced

protected int previouslyReplaced(java.lang.Object o)

addReplacement

protected void addReplacement(java.lang.Object orig,
                              java.lang.Object replacement)

previouslyWritten

protected int previouslyWritten(java.lang.Object o)

writeObjectInternal

protected org.w3c.dom.Element writeObjectInternal(java.lang.Object obj)
                                           throws java.io.IOException

java.io.IOException

writeObjectOverride

protected void writeObjectOverride(java.lang.Object obj)
                            throws java.io.IOException

Overrides:

writeObjectOverride in class java.io.ObjectOutputStream

java.io.IOException

writeNewClass

protected org.w3c.dom.Element writeNewClass(java.lang.Class clazz)
                                     throws java.io.IOException

java.io.IOException

writeClassDescriptor

protected org.w3c.dom.Element writeClassDescriptor(ClassDescriptor desc)
                                            throws java.io.IOException

java.io.IOException

writeSuperclassDescriptor

protected void writeSuperclassDescriptor(ClassDescriptor desc)
                                  throws java.io.IOException

java.io.IOException

writeNewClassDescriptor

protected org.w3c.dom.Element writeNewClassDescriptor(ClassDescriptor desc)
                                               throws java.io.IOException

java.io.IOException

writeFields

protected void writeFields(java.lang.reflect.Field[] fields)
                    throws java.io.IOException

java.io.IOException

writeFieldDescriptor

protected void writeFieldDescriptor(java.lang.reflect.Field field)
                             throws java.io.IOException

java.io.IOException

writeNewArray

protected org.w3c.dom.Element writeNewArray(java.lang.Object array)
                                     throws java.io.IOException

java.io.IOException

writeNewObject

protected org.w3c.dom.Element writeNewObject(java.lang.Object obj)
                                      throws java.io.IOException

java.io.IOException

defaultWriteObject

protected void defaultWriteObject(java.lang.Object obj,
                                  ClassDescriptor currentClassDesc)
                           throws java.io.IOException

java.io.IOException

outputClassFields

protected void outputClassFields(java.lang.Object obj,
                                 java.lang.Class clazz,
                                 java.lang.reflect.Field[] fields)
                          throws java.io.IOException

java.io.IOException

hasWriteObjectMethod

protected boolean hasWriteObjectMethod(ClassDescriptor desc)
                                throws java.io.IOException

java.io.IOException

invokeObjectWriter

protected void invokeObjectWriter(java.lang.Object obj,
                                  ClassDescriptor desc)
                           throws java.io.IOException

java.io.IOException

writeNewString

protected org.w3c.dom.Element writeNewString(java.lang.String string)
                                      throws java.io.IOException

java.io.IOException

writeNull

protected org.w3c.dom.Element writeNull(java.lang.Object o)
                                 throws java.io.IOException

java.io.IOException

main

public static void main(java.lang.String[] args)