org.extex.scanner.stream
Class TokenStreamFactory

java.lang.Object
  org.extex.framework.AbstractFactory
      org.extex.scanner.stream.TokenStreamFactory

All Implemented Interfaces:

Configurable, LogEnabled, RegistrarObserver, ResourceAware, OpenFileObservable, OpenReaderObservable, OpenStringObservable, OpenWriterObservable

public class TokenStreamFactory
extends AbstractFactory
implements OpenFileObservable, OpenStringObservable, OpenReaderObservable, OpenWriterObservable

This is the factory to provide an instance of a TokenStream. Like any good factory it is controlled by its configuration.

Configuration

Mainly the configuration needs to specify which class to use for the TokenStream. The name of the class is given as the argument class as shown below.

   <Scanner class="the.pack.age.TheClass"/>
 

The class given must implement the interface TokenStream. In addition an appropriate constructor is required:

     public TheClass(Configuration config, Reader reader, Boolean isFile,
          String theSource) throws IOException
 

If the Token stream is fed from a file then the additional parameter buffersize is taken into account. This parameter is optional. Its usage can look as follows:

   <Scanner class="the.pack.age.TheClass"
         buffersize="0"/>
 

The value given is a number. If this number is positive then it is interpreted as the size of the buffer for the file reading operation. If it is 0 or empty then no buffer will be used. If it is negative, then the default buffer size will be used.

In addition to the class for the Token stream the reader class can be specified for the case that reading from a file is requested. In this case the mapping from bytes to characters according to an encoding. The name is given as the parameter reader as shown below:

   <Scanner class="the.pack.age.TheClass"
         reader="another.pack.age.TheReaderClass"/>
 

Note that the attribute reader is optional. If none is given or the value is the empty string then java.io.InputStreamReader is used instead.

Observable Events

Observers can be registered for several events:

file

This event is triggered by the request for a TokenStream fed from a file. It is deferred until the file has been found and opened. The name of the file is passed as argument to the observer.

reader

This event is triggered by the request for a TokenStream fed from an arbitrary Reader. The reader is passed as argument to the observer.

string

This event is triggered by the request for a TokenStream fed from a String. The string is passed as argument to the observer.

Version:

$Revision:5563 $

Author:

Gerd Neugebauer, Michael Niedermair

Field Summary

Fields inherited from class org.extex.framework.AbstractFactory

DEFAULT_ATTRIBUTE, SELECT_ATTRIBUTE

Constructor Summary

TokenStreamFactory(java.lang.String tag)
Creates a new object.

Method Summary

void	configure(Configuration config) Configure an object according to a given Configuration.
TokenStream	getStream(java.lang.CharSequence line) Provide a new instance of a token stream reading from a string.
TokenStream	getStream(java.io.Reader reader) Provide a new instance of a token stream reading from a Reader.
protected TokenStream	getStream(java.io.Reader reader, java.lang.Boolean isFile, java.lang.String source) Provide a new instance of a token stream reading from a Reader.
TokenStream	getStream(java.lang.String name, java.lang.String type, java.lang.String encoding) Provide a new instance of a token stream reading from a file or other resource.
void	register(InputStreamInterceptor interceptor) Register an input stream interceptor to be applied for each token stream originated at a resource.
void	register(OutputStreamInterceptor interceptor) Register an output stream interceptor to be applied for each output stream.
void	register(ReaderInterceptor interceptor) Register a reader interceptor to be applied for each token stream originated at a resource.
void	register(WriterInterceptor interceptor) Register a writer interceptor to be applied for each writer.
void	registerObserver(OpenFileObserver observer) Register an open file observer for later use.
void	registerObserver(OpenReaderObserver observer) Register an open reader observer for later use.
void	registerObserver(OpenStringObserver observer) Register an open string observer for later use.
void	registerObserver(OpenWriterObserver observer) Register an open reader observer for later use.
void	setOptions(TokenStreamOptions options) Setter for options.
java.io.Writer	writerStream(java.io.OutputStream stream, java.lang.String key, java.lang.String encoding) Construct a Writer for an output stream.

Methods inherited from class org.extex.framework.AbstractFactory

configure, createInstance, createInstance, createInstance, createInstance, createInstanceForConfiguration, createInstanceForConfiguration, createInstanceForConfiguration, enableLogging, enableLogging, getConfiguration, getLogger, getResourceFinder, reconnect, selectConfiguration, setResourceFinder

Methods inherited from class java.lang.Object

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

Constructor Detail

TokenStreamFactory

public TokenStreamFactory(java.lang.String tag)
                   throws ConfigurationException

Creates a new object.

Parameters:

tag - the tag name of the sub-configuration to use

Throws:

ConfigurationException - in case of an error in the configuration

Method Detail

configure

public void configure(Configuration config)
               throws ConfigurationException

Configure an object according to a given Configuration.

Specified by:

configure in interface Configurable

Overrides:

configure in class AbstractFactory

Parameters:

config - the configuration object to consider

Throws:

ConfigurationException - in case that something went wrong

See Also:

AbstractFactory.configure( org.extex.framework.configuration.Configuration)

getStream

public TokenStream getStream(java.lang.CharSequence line)
                      throws ConfigurationException

Provide a new instance of a token stream reading from a string.

Parameters:

line - the line of input to read from

Returns:

the new instance

Throws:

ConfigurationException - in case of an error in the configuration

getStream

public TokenStream getStream(java.io.Reader reader)
                      throws ConfigurationException

Provide a new instance of a token stream reading from a Reader.

Parameters:

reader - the reader to get new characters from

Returns:

the new instance

Throws:

ConfigurationException - in case of an error in the configuration

getStream

protected TokenStream getStream(java.io.Reader reader,
                                java.lang.Boolean isFile,
                                java.lang.String source)
                         throws ConfigurationException

Provide a new instance of a token stream reading from a Reader.

Parameters:

reader - the reader to get new characters from

isFile - the indicator for file readers

source - the description of the source

Returns:

the new instance

Throws:

ConfigurationException - in case of an error in the configuration

getStream

public TokenStream getStream(java.lang.String name,
                             java.lang.String type,
                             java.lang.String encoding)
                      throws ConfigurationException

Provide a new instance of a token stream reading from a file or other resource.

Parameters:

name - the name of the file to be read

type - the type of the file to be read

encoding - the name of the encoding to use

Returns:

the new instance or null if the resource could not be located

Throws:

ConfigurationException - in case of an error in the configuration

register

public void register(InputStreamInterceptor interceptor)

Register an input stream interceptor to be applied for each token stream originated at a resource.

Parameters:

interceptor - the additional interceptor

register

public void register(OutputStreamInterceptor interceptor)

Register an output stream interceptor to be applied for each output stream.

Parameters:

interceptor - the additional interceptor

register

public void register(ReaderInterceptor interceptor)

Register a reader interceptor to be applied for each token stream originated at a resource.

Parameters:

interceptor - the additional interceptor

register

public void register(WriterInterceptor interceptor)

Register a writer interceptor to be applied for each writer.

Parameters:

interceptor - the additional interceptor

registerObserver

public void registerObserver(OpenFileObserver observer)

Description copied from interface: OpenFileObservable

Register an open file observer for later use.

Specified by:

registerObserver in interface OpenFileObservable

Parameters:

observer - the observer to be registered

See Also:

OpenFileObservable.registerObserver( org.extex.scanner.stream.observer.file.OpenFileObserver)

registerObserver

public void registerObserver(OpenReaderObserver observer)

Description copied from interface: OpenReaderObservable

Register an open reader observer for later use.

Specified by:

registerObserver in interface OpenReaderObservable

Parameters:

observer - the observer to be registered

See Also:

OpenReaderObservable.registerObserver( org.extex.scanner.stream.observer.reader.OpenReaderObserver)

registerObserver

public void registerObserver(OpenStringObserver observer)

Description copied from interface: OpenStringObservable

Register an open string observer for later use.

Specified by:

registerObserver in interface OpenStringObservable

Parameters:

observer - the observer to be registered

See Also:

OpenStringObservable.registerObserver( org.extex.scanner.stream.observer.string.OpenStringObserver)

registerObserver

public void registerObserver(OpenWriterObserver observer)

Register an open reader observer for later use.

Specified by:

registerObserver in interface OpenWriterObservable

Parameters:

observer - the observer to be registered

See Also:

OpenWriterObservable.registerObserver( org.extex.scanner.stream.observer.writer.OpenWriterObserver)

setOptions

public void setOptions(TokenStreamOptions options)

Setter for options.

Parameters:

options - the options to set.

writerStream

public java.io.Writer writerStream(java.io.OutputStream stream,
                                   java.lang.String key,
                                   java.lang.String encoding)
                            throws java.io.UnsupportedEncodingException

Construct a Writer for an output stream. This may build up a pipe of output stream and writers to perform all desirable steps.

The encoding can be given as a hint.

Parameters:

stream - the stream to put bytes to

key - the name in terms of the interpreter

encoding - the optional encoding. If the encoding is null then it is ignored

Returns:

the writer for the task

Throws:

java.io.UnsupportedEncodingException - in case of an error with the encoding