Class XmlApp

java.lang.Object

XmlApp

All Implemented Interfaces:

XmlHandler

Direct Known Subclasses:

DtdDemo, EventDemo, TimerDemo

public class XmlApp
extends java.lang.Object
implements XmlHandler

Base class for Ælfred demonstration applications.

This class fills in the basic interface, and provides an I/O infrastructure for simple applications and applets.

See Also:

XmlParser, XmlHandler, EventDemo, TimerDemo, DtdDemo, StreamDemo

Field Summary

Fields

Modifier and Type	Field and Description
boolean	isApplet Flag to show whether we're running as an applet or application.
XmlParser	parser

Constructor Summary

Constructors

Constructor and Description
XmlApp()

Method Summary

Modifier and Type	Method and Description
void	attribute(java.lang.String name, java.lang.String value, boolean isSpecified) Handle an attribute value specification.
void	charData(char[] ch, int start, int length) Handle character data.
void	doctypeDecl(java.lang.String name, java.lang.String pubid, java.lang.String sysid) Handle a DOCTYPE declaration.
void	endDocument() Handle the end the document.
void	endElement(java.lang.String name) Handle the end of an element.
void	endExternalEntity(java.lang.String systemId) End an external entity.
void	error(java.lang.String message, java.lang.String url, int line, int column) Handle a parsing error.
void	ignorableWhitespace(char[] ch, int start, int length) Handle ignorable whitespace.
void	processingInstruction(java.lang.String target, java.lang.String data) Handle a processing instruction.
java.lang.Object	resolveEntity(java.lang.String publicId, java.lang.String systemId) Resolve an external entity.
void	startDocument() Handle the start of the document.
void	startElement(java.lang.String name) Handle the start of an element.
void	startExternalEntity(java.lang.String systemId) Begin an external entity.

Methods inherited from class java.lang.Object

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

Field Detail

isApplet

public boolean isApplet

Flag to show whether we're running as an applet or application.

parser

public XmlParser parser

Constructor Detail

XmlApp

public XmlApp()

Method Detail

resolveEntity

public java.lang.Object resolveEntity(java.lang.String publicId,
                                      java.lang.String systemId)

Resolve an external entity.

This method could generate a new URL by looking up the public identifier in a hash table, or it could replace the URL supplied with a different, local one; for now, however, just return the URL supplied.

Specified by:

resolveEntity in interface XmlHandler

Parameters:

publicId - The public identifier, or null if none was supplied.

systemId - The system identifier.

Returns:

The replacement system identifier, or null to use the default.

See Also:

com.Microstar.xml.XmlHandler#resolveEntity

startExternalEntity

public void startExternalEntity(java.lang.String systemId)

Description copied from interface: XmlHandler

Begin an external entity.

Ælfred will call this method at the beginning of each external entity, including the top-level document entity and the external DTD subset (if any).

If necessary, you can use this method to track the location of the current entity so that you can resolve relative URIs correctly.

Specified by:

startExternalEntity in interface XmlHandler

Parameters:

systemId - The URI of the external entity that is starting.

See Also:

XmlHandler.endExternalEntity(java.lang.String), XmlHandler.resolveEntity(java.lang.String, java.lang.String)

endExternalEntity

public void endExternalEntity(java.lang.String systemId)

Description copied from interface: XmlHandler

End an external entity.

Ælfred will call this method at the end of each external entity, including the top-level document entity and the external DTD subset.

If necessary, you can use this method to track the location of the current entity so that you can resolve relative URIs correctly.

Specified by:

endExternalEntity in interface XmlHandler

Parameters:

systemId - The URI of the external entity that is ending.

See Also:

XmlHandler.startExternalEntity(java.lang.String), XmlHandler.resolveEntity(java.lang.String, java.lang.String)

startDocument

public void startDocument()

Handle the start of the document.

Do nothing for now. Subclasses can override this method if they want to take a specific action.

This method will always be called first.

Specified by:

startDocument in interface XmlHandler

See Also:

com.Microstar.xml.XmlHandler#startDocument

endDocument

public void endDocument()

Handle the end the document.

Do nothing for now. Subclasses can override this method if they want to take a specific action.

This method will always be called last.

Specified by:

endDocument in interface XmlHandler

See Also:

com.Microstar.xml.XmlHandler#endDocument

doctypeDecl

public void doctypeDecl(java.lang.String name,
                        java.lang.String pubid,
                        java.lang.String sysid)

Handle a DOCTYPE declaration.

Do nothing for now. Subclasses can override this method if they want to take a specific action.

Well-formed XML documents might not have one of these.

The query methods in XmlParser will return useful values only after this callback.

Specified by:

doctypeDecl in interface XmlHandler

Parameters:

name - The document type name.

pubid - The public identifier, or null if unspecified.

sysid - The system identifier, or null if unspecified.

See Also:

com.Microstar.xml.XmlHandler#doctypeDecl

attribute

public void attribute(java.lang.String name,
                      java.lang.String value,
                      boolean isSpecified)

Handle an attribute value specification.

Do nothing for now. Subclasses can override this method if they want to take a specific action.

Specified by:

attribute in interface XmlHandler

value - The value of the attribute, or null if the attribute is #IMPLIED.

isSpecified - True if the value was specified, false if it was defaulted from the DTD.

See Also:

com.Microstar.xml.XmlHandler#attribute

startElement

public void startElement(java.lang.String name)

Handle the start of an element.

Do nothing for now. Subclasses can override this method if they want to take a specific action.

Specified by:

startElement in interface XmlHandler

Parameters:

name - The element type name.

See Also:

com.Microstar.xml.XmlHandler#startElement

endElement

public void endElement(java.lang.String name)

Handle the end of an element.

Do nothing for now. Subclasses can override this method if they want to take a specific action.

Specified by:

endElement in interface XmlHandler

Parameters:

name - The element type name.

See Also:

com.Microstar.xml.XmlHandler#endElement

charData

public void charData(char[] ch,
                     int start,
                     int length)

Handle character data.

Do nothing for now. Subclasses can override this method if they want to take a specific action.

Specified by:

charData in interface XmlHandler

Parameters:

ch - The character data.

start - The starting position in the array.

length - The number of characters available.

See Also:

com.Microstar.xml.XmlHandler#charData

ignorableWhitespace

public void ignorableWhitespace(char[] ch,
                                int start,
                                int length)

Handle ignorable whitespace.

Do nothing for now. Subclasses can override this method if they want to take a specific action.

Specified by:

ignorableWhitespace in interface XmlHandler

Parameters:

ch - The literal whitespace characters.

start - The starting position in the array.

length - The number of whitespace characters available.

See Also:

com.Microstar.xml.XmlHandler#ignorableWhitespace

processingInstruction

public void processingInstruction(java.lang.String target,
                                  java.lang.String data)

Handle a processing instruction.

Do nothing for now. Subclasses can override this method if they want to take a specific action.

Specified by:

processingInstruction in interface XmlHandler

Parameters:

target - The target (the name at the start of the PI).

data - The data, if any (the rest of the PI).

See Also:

com.Microstar.xml.XmlHandler#processingInstruction

error

public void error(java.lang.String message,
                  java.lang.String url,
                  int line,
                  int column)

Handle a parsing error.

By default, print a message and throw an Error.

Subclasses can override this method if they want to do something different.

Specified by:

error in interface XmlHandler

Parameters:

message - The error message.

url - The system identifier of the entity that contains the error.

line - The approximate line number of the error.

column - The approximate column number of the error.

See Also:

com.Microstar.xml.XmlHandler#error