org.apache.turbine.modules.screens
Class RawScreen

java.lang.Object
  org.apache.turbine.modules.Assembler
      org.apache.turbine.modules.Screen
          org.apache.turbine.modules.screens.RawScreen

Direct Known Subclasses:

JSONScreen

public abstract class RawScreen

extends Screen

Base class for writing Screens that output binary data. This class is provided as a helper class for those who want to write Screens that output raw binary data. For example, it may be extended into a Screen that outputs a SVG file or a SWF (Flash Player format) movie. The only thing one has to do is to implement the two methods getContentType(RunData data) and doOutput(RunData data) (see below).

You migth want to take a look at the ImageServer screen class contained in the TDK.

Version:

$Id: RawScreen.java 534527 2007-05-02 16:10:59Z tv $

Author:

Regis Koenig

Constructor Summary

RawScreen()

Method Summary

protected org.apache.ecs.ConcreteElement	doBuild(RunData data) Build the Screen.
protected abstract void	doOutput(RunData data) Actually output the dynamic content.
protected abstract java.lang.String	getContentType(RunData data) Set the content type.
java.lang.String	getLayout(RunData data) The layout must be set to null.

Methods inherited from class org.apache.turbine.modules.Screen

build, prepareText, prepareTextMinimum, setLayout

Methods inherited from class java.lang.Object

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

Constructor Detail

RawScreen

public RawScreen()

Method Detail

doBuild

protected final org.apache.ecs.ConcreteElement doBuild(RunData data)
                                                throws java.lang.Exception

Build the Screen. This method actually makes a call to the doOutput() method in order to generate the Screen content.

Specified by:

doBuild in class Screen

Parameters:

data - Turbine information.

Returns:

A ConcreteElement.

Throws:

Exception, - a generic exception.

java.lang.Exception - a generic exception.

getContentType

protected abstract java.lang.String getContentType(RunData data)

Set the content type. This method should be overidden to actually set the real content-type header of the output.

Parameters:

data - Turbine information.

Returns:

A String with the content type.

doOutput

protected abstract void doOutput(RunData data)
                          throws java.lang.Exception

Actually output the dynamic content. The OutputStream can be accessed like this:

OutputStream out =
 data.getResponse().getOutputStream();

.

Parameters:

data - Turbine information.

Throws:

Exception, - a generic exception.

java.lang.Exception

getLayout

public final java.lang.String getLayout(RunData data)

The layout must be set to null.

Overrides:

getLayout in class Screen

Parameters:

data - Turbine information.

Returns:

A null String.