com.thoughtworks.xstream.io

Class ReaderWrapper

java.lang.Object

com.thoughtworks.xstream.io.ReaderWrapper

All Implemented Interfaces:

ErrorReporter, ExtendedHierarchicalStreamReader, HierarchicalStreamReader

Direct Known Subclasses:

PathTrackingReader

public abstract class ReaderWrapper
extends Object
implements ExtendedHierarchicalStreamReader

Base class to make it easy to create wrappers (decorators) for HierarchicalStreamReader.

Author:

Joe Walnes

Field Summary

Fields

Modifier and Type	Field and Description
protected HierarchicalStreamReader	wrapped

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	ReaderWrapper(HierarchicalStreamReader reader)

Method Summary

Modifier and Type	Method and Description
void	appendErrors(ErrorWriter errorWriter) If any errors are detected, allow the reader to add any additional information that can aid debugging (such as line numbers, XPath expressions, etc).
void	close() Close the reader, if necessary.
String	getAttribute(int index) Get the value of an attribute of the current node, by index.
String	getAttribute(String name) Get the value of an attribute of the current node.
int	getAttributeCount() Number of attributes in current node.
String	getAttributeName(int index) Name of attribute in current node.
Iterator	getAttributeNames() Iterator with the names of the attributes.
String	getNodeName() Get the name of the current node.
String	getValue() Get the value (text content) of the current node.
boolean	hasMoreChildren() Does the node have any more children remaining that have not yet been read?
void	moveDown() Select the current child as current node.
void	moveUp() Select the parent node as current node.
String	peekNextChild() Peek the name of the next child.
HierarchicalStreamReader	underlyingReader() Return the underlying HierarchicalStreamReader implementation.

Methods inherited from class java.lang.Object

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

Field Detail

wrapped

protected HierarchicalStreamReader wrapped

Constructor Detail

ReaderWrapper

protected ReaderWrapper(HierarchicalStreamReader reader)

Method Detail

hasMoreChildren

public boolean hasMoreChildren()

Description copied from interface: HierarchicalStreamReader

Does the node have any more children remaining that have not yet been read?

Specified by:

hasMoreChildren in interface HierarchicalStreamReader

moveDown

public void moveDown()

Description copied from interface: HierarchicalStreamReader

Select the current child as current node. A call to this function must be balanced with a call to HierarchicalStreamReader.moveUp().

Specified by:

moveDown in interface HierarchicalStreamReader

moveUp

public void moveUp()

Description copied from interface: HierarchicalStreamReader

Select the parent node as current node.

Specified by:

moveUp in interface HierarchicalStreamReader

getNodeName

public String getNodeName()

Description copied from interface: HierarchicalStreamReader

Get the name of the current node.

Specified by:

getNodeName in interface HierarchicalStreamReader

getValue

public String getValue()

Description copied from interface: HierarchicalStreamReader

Get the value (text content) of the current node.

Specified by:

getValue in interface HierarchicalStreamReader

getAttribute

public String getAttribute(String name)

Description copied from interface: HierarchicalStreamReader

Get the value of an attribute of the current node.

If no such attribute exists, the method returns null.

Specified by:

getAttribute in interface HierarchicalStreamReader

getAttribute

public String getAttribute(int index)

Description copied from interface: HierarchicalStreamReader

Get the value of an attribute of the current node, by index.

Note, the behavior of this method is dependent on the underlying parser when calling it with a non-existing index. Typically some kind of RuntimeException is thrown.

Specified by:

getAttribute in interface HierarchicalStreamReader

getAttributeCount

public int getAttributeCount()

Description copied from interface: HierarchicalStreamReader

Number of attributes in current node.

Specified by:

getAttributeCount in interface HierarchicalStreamReader

getAttributeName

public String getAttributeName(int index)

Description copied from interface: HierarchicalStreamReader

Name of attribute in current node.

Note, the behavior of this method is dependent on the underlying parser when calling it with a non-existing index. Typically some kind of RuntimeException is thrown.

Specified by:

getAttributeName in interface HierarchicalStreamReader

getAttributeNames

public Iterator getAttributeNames()

Description copied from interface: HierarchicalStreamReader

Iterator with the names of the attributes.

Note, the iterator is only valid as long as the internal state of the underlying parser is still at the start of the current element. The behavior is undefined if the parser moved on.

Specified by:

getAttributeNames in interface HierarchicalStreamReader

appendErrors

public void appendErrors(ErrorWriter errorWriter)

Description copied from interface: HierarchicalStreamReader

If any errors are detected, allow the reader to add any additional information that can aid debugging (such as line numbers, XPath expressions, etc).

Specified by:

appendErrors in interface ErrorReporter

Specified by:

appendErrors in interface HierarchicalStreamReader

Parameters:

errorWriter - the error writer

close

public void close()

Description copied from interface: HierarchicalStreamReader

Close the reader, if necessary.

Specified by:

close in interface HierarchicalStreamReader

peekNextChild

public String peekNextChild()

Description copied from interface: ExtendedHierarchicalStreamReader

Peek the name of the next child. In situation where HierarchicalStreamReader.hasMoreChildren() returns true, peek the tag name of the child.

Specified by:

peekNextChild in interface ExtendedHierarchicalStreamReader

underlyingReader

public HierarchicalStreamReader underlyingReader()

Description copied from interface: HierarchicalStreamReader

Return the underlying HierarchicalStreamReader implementation.

If a Converter needs to access methods of a specific HierarchicalStreamReader implementation that are not defined in the HierarchicalStreamReader interface, it should call this method before casting. This is because the reader passed to the Converter is often wrapped/decorated by another implementation to provide additional functionality (such as XPath tracking).

For example:

MySpecificReader mySpecificReader = (MySpecificReader)reader; // INCORRECT!
 mySpecificReader.doSomethingSpecific();

MySpecificReader mySpecificReader = (MySpecificReader)reader.underlyingReader();  // CORRECT!
 mySpecificReader.doSomethingSpecific();

Implementations of HierarchicalStreamReader should return 'this', unless they are a decorator, in which case they should delegate to whatever they are wrapping.

Specified by:

underlyingReader in interface HierarchicalStreamReader