JSX
Class ObjectReader

java.lang.Object
  |
  +--java.io.InputStream
        |
        +--java.io.ObjectInputStream
              |
              +--JSX.ObjectReader

All Implemented Interfaces:

DataInput, ObjectInput, ObjectStreamConstants

public class ObjectReader

extends ObjectInputStream

ObjectReader can be used in place of ObjectInputStream, to serialize object graphs to XML, instead of the binary format. It implements all the core features of ObjectInputStream - refer to Sun's javadocs and tutorials for more information. ObjectReader does not require classes to implement java.io.Serialization, nor is serialVersionUID needed for class evolution.

See Also:

Object Serialization Specification, Section 3, Object Input Classes

Nested Class Summary

class

ObjectReader.GetFieldImpl

Field Summary

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

ObjectReader(JSX.DataReaderI dataReader)

ObjectReader(JSX.DataReaderI dataReader, ClassLoader cl)
Pass in a classloader for JSX to lookup classes that are being deserialized.

ObjectReader(InputStream in)

ObjectReader(InputStream in, ClassLoader cl)
Pass in a classloader for JSX to lookup classes that are being deserialized.

ObjectReader(Reader reader)

ObjectReader(Reader reader, ClassLoader cl)
Pass in a classloader for JSX to lookup classes that are being deserialized.

Method Summary

String	_readUTF()
int	available() returns 1 if source is ready; else 0
void	close()
void	defaultReadObject() Call from within a class's readObject(ObjectInputStream ois) method, so the object is deserialized by the default way.
void	disableExternalization() Create object and step through inherited classes
protected boolean	enableResolveObject(boolean enable)
HashMap	getHash()
static void	main(String[] args) USAGE: java JSX.ObjectReader fileName (use "-" for stdin, defaults to example.xml)
int	read()
int	read(byte[] buf, int off, int len)
boolean	readBoolean()
byte	readByte()
char	readChar()
protected ObjectStreamClass	readClassDescriptor() Never called by JSX, so overriding it has no effect.
double	readDouble()
ObjectInputStream.GetField	readFields() Reads the stream, same as defaultReadObject, but instead of storing into fields, it stores it in a hash that can be queried.
float	readFloat()
void	readFully(byte[] buf)
void	readFully(byte[] buf, int off, int len)
int	readInt()
String	readLine() This operates at the wrong level for reading object encoded as XML - this method calls _readUTF() instead, and so will work if characters have been written explicitly as object data
long	readLong()
protected Object	readObjectOverride()
short	readShort()
protected void	readStreamHeader() Not implemented
Object	readUnshared()
int	readUnsignedByte()
int	readUnsignedShort()
String	readUTF()
void	registerValidation(ObjectInputValidation obj, int prio)
protected Class	resolveClass(ObjectStreamClass osc, String sergeyName) First attempts to load classes with Thread.currentThread().getContextClassLoader(); if fails, it defaults to the classloader that loaded JSX.Reader.
protected Object	resolveObject(Object obj) Override this method, to replace a deserialized object with another

Methods inherited from class java.io.ObjectInputStream

readObject, resolveClass, resolveProxyClass, skipBytes

Methods inherited from class java.io.InputStream

mark, markSupported, read, reset, skip

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.io.ObjectInput

read, skip

Constructor Detail

ObjectReader

public ObjectReader(InputStream in)
             throws IOException

ObjectReader

public ObjectReader(InputStream in,
                    ClassLoader cl)
             throws IOException

Pass in a classloader for JSX to lookup classes that are being deserialized.

ObjectReader

public ObjectReader(Reader reader)
             throws IOException

ObjectReader

public ObjectReader(Reader reader,
                    ClassLoader cl)
             throws IOException

Pass in a classloader for JSX to lookup classes that are being deserialized.

ObjectReader

public ObjectReader(JSX.DataReaderI dataReader)
             throws IOException

ObjectReader

public ObjectReader(JSX.DataReaderI dataReader,
                    ClassLoader cl)
             throws IOException

Pass in a classloader for JSX to lookup classes that are being deserialized.

Method Detail

main

public static void main(String[] args)
                 throws IOException,
                        ClassNotFoundException

USAGE: java JSX.ObjectReader fileName (use "-" for stdin, defaults to example.xml)

IOException

ClassNotFoundException

getHash

public HashMap getHash()

close

public void close()
           throws IOException

Specified by:

close in interface ObjectInput

Overrides:

close in class ObjectInputStream

IOException

available

public int available()
              throws IOException

returns 1 if source is ready; else 0

Specified by:

available in interface ObjectInput

Overrides:

available in class ObjectInputStream

IOException

registerValidation

public void registerValidation(ObjectInputValidation obj,
                               int prio)
                        throws NotActiveException,
                               InvalidObjectException

Overrides:

registerValidation in class ObjectInputStream

NotActiveException

InvalidObjectException

readBoolean

public boolean readBoolean()
                    throws IOException

Specified by:

readBoolean in interface DataInput

Overrides:

readBoolean in class ObjectInputStream

IOException

readByte

public byte readByte()
              throws IOException

Specified by:

readByte in interface DataInput

Overrides:

readByte in class ObjectInputStream

IOException

readChar

public char readChar()
              throws IOException

Specified by:

readChar in interface DataInput

Overrides:

readChar in class ObjectInputStream

IOException

readUnsignedByte

public int readUnsignedByte()
                     throws IOException

Specified by:

readUnsignedByte in interface DataInput

Overrides:

readUnsignedByte in class ObjectInputStream

IOException

readShort

public short readShort()
                throws IOException

Specified by:

readShort in interface DataInput

Overrides:

readShort in class ObjectInputStream

IOException

readUnsignedShort

public int readUnsignedShort()
                      throws IOException

Specified by:

readUnsignedShort in interface DataInput

Overrides:

readUnsignedShort in class ObjectInputStream

IOException

readInt

public int readInt()
            throws IOException

Specified by:

readInt in interface DataInput

Overrides:

readInt in class ObjectInputStream

IOException

readLong

public long readLong()
              throws IOException

Specified by:

readLong in interface DataInput

Overrides:

readLong in class ObjectInputStream

IOException

readFloat

public float readFloat()
                throws IOException

Specified by:

readFloat in interface DataInput

Overrides:

readFloat in class ObjectInputStream

IOException

readDouble

public double readDouble()
                  throws IOException

Specified by:

readDouble in interface DataInput

Overrides:

readDouble in class ObjectInputStream

IOException

readLine

public String readLine()
                throws IOException

This operates at the wrong level for reading object encoded as XML - this method calls _readUTF() instead, and so will work if characters have been written explicitly as object data

Specified by:

readLine in interface DataInput

Overrides:

readLine in class ObjectInputStream

IOException

readUTF

public String readUTF()
               throws IOException

Specified by:

readUTF in interface DataInput

Overrides:

readUTF in class ObjectInputStream

IOException

read

public int read()
         throws IOException

Specified by:

read in interface ObjectInput

Overrides:

read in class ObjectInputStream

IOException

read

public int read(byte[] buf,
                int off,
                int len)
         throws IOException

Specified by:

read in interface ObjectInput

Overrides:

read in class ObjectInputStream

IOException

readFully

public void readFully(byte[] buf)
               throws IOException

Specified by:

readFully in interface DataInput

Overrides:

readFully in class ObjectInputStream

IOException

readFully

public void readFully(byte[] buf,
                      int off,
                      int len)
               throws IOException

Specified by:

readFully in interface DataInput

Overrides:

readFully in class ObjectInputStream

IOException

_readUTF

public String _readUTF()
                throws IOException

IOException

readUnshared

public Object readUnshared()
                    throws OptionalDataException,
                           ClassNotFoundException,
                           IOException

Overrides:

readUnshared in class ObjectInputStream

OptionalDataException

ClassNotFoundException

IOException

resolveObject

protected Object resolveObject(Object obj)
                        throws IOException

Override this method, to replace a deserialized object with another

Overrides:

resolveObject in class ObjectInputStream

IOException

enableResolveObject

protected boolean enableResolveObject(boolean enable)
                               throws SecurityException

Overrides:

enableResolveObject in class ObjectInputStream

SecurityException

resolveClass

protected Class resolveClass(ObjectStreamClass osc,
                             String sergeyName)
                      throws IOException,
                             ClassNotFoundException

First attempts to load classes with Thread.currentThread().getContextClassLoader(); if fails, it defaults to the classloader that loaded JSX.Reader. Override this method to implement your own classloading strategy.

IOException

ClassNotFoundException

readClassDescriptor

protected ObjectStreamClass readClassDescriptor()
                                         throws IOException,
                                                ClassNotFoundException

Never called by JSX, so overriding it has no effect. (JOS uses it so you can reimplement the code for parsing an ObjectStreamClass - but JSX doesn't use these, so it makes no sense)

Overrides:

readClassDescriptor in class ObjectInputStream

IOException

ClassNotFoundException

readStreamHeader

protected void readStreamHeader()
                         throws IOException,
                                StreamCorruptedException

Not implemented

Overrides:

readStreamHeader in class ObjectInputStream

IOException

StreamCorruptedException

readObjectOverride

protected Object readObjectOverride()
                             throws IOException,
                                    ClassNotFoundException

Overrides:

readObjectOverride in class ObjectInputStream

IOException

ClassNotFoundException

disableExternalization

public void disableExternalization()

Create object and step through inherited classes

defaultReadObject

public void defaultReadObject()
                       throws IOException,
                              ClassNotFoundException

Call from within a class's readObject(ObjectInputStream ois) method, so the object is deserialized by the default way. A class can control how its objects are deserialized, by having a readObject(ObjectInputStream ois) method, which JSX will call instead of deserializing it in the default way. The class will then have to explicitly read its custom format (with readInt() etc); to avoid this work, call defaultReadObject instead. This technique is very useful if you want to execute some code just after an object is deserialized, such as initialization code

Overrides:

defaultReadObject in class ObjectInputStream

IOException

ClassNotFoundException

readFields

public ObjectInputStream.GetField readFields()
                                      throws IOException,
                                             ClassNotFoundException

Reads the stream, same as defaultReadObject, but instead of storing into fields, it stores it in a hash that can be queried.
Not implemented: public ObjectStreamClass getObjectStreamClass();

Overrides:

readFields in class ObjectInputStream

IOException

ClassNotFoundException