Class XMLDecoder

java.lang.Object

java.beans.XMLDecoder

All Implemented Interfaces:

AutoCloseable

public class XMLDecoder
extends Object
implements AutoCloseable

The XMLDecoder class is used to read XML documents created using the XMLEncoder and is used just like the ObjectInputStream. For example, one can use the following fragment to read the first object defined in an XML document written by the XMLEncoder class:

       XMLDecoder d = new XMLDecoder(
                          new BufferedInputStream(
                              new FileInputStream("Test.xml")));
       Object result = d.readObject();
       d.close();
 

For more information you might also want to check out Long Term Persistence of JavaBeans Components: XML Schema, an article in The Swing Connection.

Since:

1.4

See Also:

• XMLEncoder
• ObjectInputStream

Constructor Summary

Constructors

Constructor	Description
XMLDecoder(InputStream in)	Creates a new input stream for reading archives created by the XMLEncoder class.
XMLDecoder(InputStream in, Object owner)	Creates a new input stream for reading archives created by the XMLEncoder class.
XMLDecoder(InputStream in, Object owner, ExceptionListener exceptionListener)	Creates a new input stream for reading archives created by the XMLEncoder class.
XMLDecoder(InputStream in, Object owner, ExceptionListener exceptionListener, ClassLoader cl)	Creates a new input stream for reading archives created by the XMLEncoder class.
XMLDecoder(InputSource is)	Creates a new decoder to parse XML archives created by the XMLEncoder class.

Method Summary

Modifier and Type	Method	Description
void	close()	This method closes the input stream associated with this stream.
static DefaultHandler	createHandler(Object owner, ExceptionListener el, ClassLoader cl)	Creates a new handler for SAX parser that can be used to parse embedded XML archives created by the XMLEncoder class.
ExceptionListener	getExceptionListener()	Gets the exception handler for this stream.
Object	getOwner()	Gets the owner of this decoder.
Object	readObject()	Reads the next object from the underlying input stream.
void	setExceptionListener(ExceptionListener exceptionListener)	Sets the exception handler for this stream to exceptionListener.
void	setOwner(Object owner)	Sets the owner of this decoder to owner.

Methods declared in class Object

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

Modifier and Type	Method	Description
protected Object	clone()	Answers a new instance of the same class as the receiver, whose slots have been filled in with the values in the slots of the receiver.
boolean	equals(Object o)	Compares the argument to the receiver, and answers true if they represent the same object using a class specific comparison.
protected void	finalize()	Deprecated, for removal: This API element is subject to removal in a future version. May cause performance issues, deadlocks and hangs.
final Class<? extends Object>	getClass()	Answers the unique instance of java.lang.Class which represents the class of the receiver.
int	hashCode()	Answers an integer hash code for the receiver.
final void	notify()	Causes one thread which is waiting on the receiver to be made ready to run.
final void	notifyAll()	Causes all threads which are waiting on the receiver to be made ready to run.
String	toString()	Answers a string containing a concise, human-readable description of the receiver.
final void	wait()	Causes the thread which sent this message to be made not ready to run pending some change in the receiver (as indicated by notify or notifyAll).
final void	wait(long time)	Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.
final void	wait(long time, int frac)	Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.

Constructor Details

XMLDecoder

public XMLDecoder(InputStream in)

Creates a new input stream for reading archives created by the XMLEncoder class.

Parameters:

in - The underlying stream.

See Also:

• XMLEncoder(java.io.OutputStream)

XMLDecoder

public XMLDecoder(InputStream in,
 Object owner)

Creates a new input stream for reading archives created by the XMLEncoder class.

Parameters:

in - The underlying stream.

owner - The owner of this stream.

XMLDecoder

public XMLDecoder(InputStream in,
 Object owner,
 ExceptionListener exceptionListener)

Creates a new input stream for reading archives created by the XMLEncoder class.

Parameters:

in - the underlying stream.

owner - the owner of this stream.

exceptionListener - the exception handler for the stream; if null the default exception listener will be used.

XMLDecoder

public XMLDecoder(InputStream in,
 Object owner,
 ExceptionListener exceptionListener,
 ClassLoader cl)

Creates a new input stream for reading archives created by the XMLEncoder class.

Parameters:

in - the underlying stream. null may be passed without error, though the resulting XMLDecoder will be useless

owner - the owner of this stream. null is a legal value

exceptionListener - the exception handler for the stream, or null to use the default

cl - the class loader used for instantiating objects. null indicates that the default class loader should be used

Since:

1.5

XMLDecoder

public XMLDecoder(InputSource is)

Creates a new decoder to parse XML archives created by the XMLEncoder class. If the input source is is null, no exception is thrown and no parsing is performed. This behavior is similar to behavior of other constructors that use InputStream as a parameter.

Parameters:

is - the input source to parse

Since:

1.7

Method Details

close

public void close()

This method closes the input stream associated with this stream.

Specified by:

close in interface AutoCloseable

setExceptionListener

public void setExceptionListener(ExceptionListener exceptionListener)

Sets the exception handler for this stream to exceptionListener. The exception handler is notified when this stream catches recoverable exceptions.

Parameters:

exceptionListener - The exception handler for this stream; if null the default exception listener will be used.

See Also:

• getExceptionListener()

getExceptionListener

public ExceptionListener getExceptionListener()

Gets the exception handler for this stream.

Returns:

The exception handler for this stream. Will return the default exception listener if this has not explicitly been set.

See Also:

• setExceptionListener(ExceptionListener)

readObject

public Object readObject()

Reads the next object from the underlying input stream.

Returns:

the next object read

Throws:

ArrayIndexOutOfBoundsException - if the stream contains no objects (or no more objects)

See Also:

• XMLEncoder.writeObject(Object)

setOwner

public void setOwner(Object owner)

Sets the owner of this decoder to owner.

Parameters:

owner - The owner of this decoder.

See Also:

• getOwner()

getOwner

public Object getOwner()

Gets the owner of this decoder.

Returns:

The owner of this decoder.

See Also:

• setOwner(Object)

createHandler

public static DefaultHandler createHandler(Object owner,
 ExceptionListener el,
 ClassLoader cl)

Creates a new handler for SAX parser that can be used to parse embedded XML archives created by the XMLEncoder class. The owner should be used if parsed XML document contains the method call within context of the <java> element. The null value may cause illegal parsing in such case. The same problem may occur, if the owner class does not contain expected method to call. See details here.

Parameters:

owner - the owner of the default handler that can be used as a value of <java> element

el - the exception handler for the parser, or null to use the default exception handler

cl - the class loader used for instantiating objects, or null to use the default class loader

Returns:

an instance of DefaultHandler for SAX parser

Since:

1.7