org.apache.portals.applications.webcontent2.rewriter.impl

Class AbstractTextLineContentRewriter

java.lang.Object

org.apache.portals.applications.webcontent2.rewriter.impl.AbstractTextLineContentRewriter

All Implemented Interfaces:

ContentRewriter

Direct Known Subclasses:

DefaultReverseProxyTextLineContentRewriter

public abstract class AbstractTextLineContentRewriter
extends Object
implements ContentRewriter

Abstract text line based content rewriter base implementation.

Constructor Summary

Constructors

Constructor and Description
AbstractTextLineContentRewriter()

Method Summary

Methods

Modifier and Type	Method and Description
void	rewrite(Source source, Sink sink, ContentRewritingContext context) Reads content from the source, transforms the content and writes to the sink.
protected abstract String	rewriteLine(String line, ContentRewritingContext context) Translates the given line and returns the translated string.

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractTextLineContentRewriter

public AbstractTextLineContentRewriter()

Method Detail

rewrite

public void rewrite(Source source,
           Sink sink,
           ContentRewritingContext context)
             throws ContentRewritingException,
                    IOException

Reads content from the source, transforms the content and writes to the sink.

This method basically gets a Reader from the source and reads each text line from the reader. And it invokes rewriteLine(String, ContentRewritingContext) method to translate the line and write the translated line to the writer retrieved from the sink.

If both source and sink are all text-based, and if it is possible to translate line by line, then you can simply create a derived class from this class with implementing rewriteLine(String, ContentRewritingContext) method.

Specified by:

rewrite in interface ContentRewriter

Parameters:

source - source of content

sink - target of content rewritten

context - content rewriting context

Throws:

ContentRewritingException

IOException

rewriteLine

protected abstract String rewriteLine(String line,
                 ContentRewritingContext context)
                               throws ContentRewritingException,
                                      IOException

Translates the given line and returns the translated string.

For example, suppose the source contains the following lines:

 ${message.greeting}
 Copyright ${copyright.holder} ${copyright.years}
 

Then, one implementation of this method might want to return "Hello, World!" for the first text line, and "Copyright Apache Software Foundation 2014" for instance to let the sink have the following:

 Hello, World!
 Copyright Apache Software Foundation 2014
 

Even better, for example, if the given context contains all those variables (i.e, ${copyright.holder} and ${copyright.years}), then the implementation of this method can resolve those variables dynamically and translates them based on the variables given by the runtime.

Parameters:

line - a text line from the source

context - the content rewriting context given by the runtime

Returns:

a translated line

Throws:

ContentRewritingException

IOException