Module com.aoapps.encoding.taglib

Package com.aoapps.encoding.taglib.legacy

Class EncodingNullBodyTag

java.lang.Object

javax.servlet.jsp.tagext.TagSupport

javax.servlet.jsp.tagext.BodyTagSupport

com.aoapps.encoding.taglib.legacy.EncodingNullBodyTag

All Implemented Interfaces:

Serializable, BodyTag, IterationTag, JspTag, Tag, TryCatchFinally

Direct Known Subclasses:

OutTag

public abstract class EncodingNullBodyTag
extends BodyTagSupport
implements TryCatchFinally

Automatically encodes its output based on tag context while discarding all content. When the direct output of the body will not be used, this will increase efficiency by discarding all write operations immediately.

Author:

AO Industries, Inc.

See Also:

• Serialized Form

Field Summary

Fields inherited from class javax.servlet.jsp.tagext.BodyTagSupport

bodyContent

Fields inherited from class javax.servlet.jsp.tagext.TagSupport

id, pageContext

Fields inherited from interface javax.servlet.jsp.tagext.BodyTag

EVAL_BODY_BUFFERED, EVAL_BODY_TAG

Fields inherited from interface javax.servlet.jsp.tagext.IterationTag

EVAL_BODY_AGAIN

Fields inherited from interface javax.servlet.jsp.tagext.Tag

EVAL_BODY_INCLUDE, EVAL_PAGE, SKIP_BODY, SKIP_PAGE

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	EncodingNullBodyTag()

Method Summary

Modifier and Type	Method	Description
int	doAfterBody()	Deprecated. You should probably be implementing in doAfterBody(java.io.Writer)
protected int	doAfterBody(Writer out)	While the out JspWriter is still replaced to output the proper content type, this version of doAfterBody() is called.
void	doCatch(Throwable t)
int	doEndTag()	Deprecated. You should probably be implementing in doEndTag(java.io.Writer)
protected int	doEndTag(Writer out)	While the out JspWriter is still replaced to output the proper content type, this version of doEndTag() is called.
void	doFinally()
void	doInitBody()	The only way to replace the "out" variable in the generated JSP is to use BodyTag.EVAL_BODY_BUFFERED.
int	doStartTag()	Deprecated. You should probably be implementing in doStartTag(java.io.Writer)
protected int	doStartTag(Writer out)	Once the out JspWriter has been replaced to output the proper content type, this version of doStartTag() is called.
abstract MediaType	getOutputType()	Gets the output type of this tag.
protected void	setMediaEncoderOptions(MediaEncoder mediaEncoder)	Sets the media encoder options.
protected void	writeEncoderPrefix(MediaEncoder mediaEncoder, Writer out)
protected void	writeEncoderSuffix(MediaEncoder mediaEncoder, Writer out, boolean trim)
protected void	writePrefix(MediaType containerType, Writer out)	Writes any prefix in the container's media type.
protected void	writeSuffix(MediaType containerType, Writer out)	Writes any suffix in the container's media type.

Methods inherited from class javax.servlet.jsp.tagext.BodyTagSupport

getBodyContent, getPreviousOut, release, setBodyContent

Methods inherited from class javax.servlet.jsp.tagext.TagSupport

findAncestorWithClass, getId, getParent, getValue, getValues, removeValue, setId, setPageContext, setParent, setValue

Methods inherited from class java.lang.Object

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

Methods inherited from interface javax.servlet.jsp.tagext.Tag

getParent, setPageContext, setParent

Constructor Details

EncodingNullBodyTag

protected EncodingNullBodyTag()

Method Details

getOutputType

public abstract MediaType getOutputType()

Gets the output type of this tag. This is used to determine the correct encoder. If the tag never has any output this should return null. When null is returned, any output will result in an error.

doStartTag

@Deprecated
public int doStartTag()
               throws JspException

Deprecated.

You should probably be implementing in doStartTag(java.io.Writer)

Specified by:

doStartTag in interface Tag

Overrides:

doStartTag in class BodyTagSupport

Throws:

JspException

See Also:

• doStartTag(java.io.Writer)

doStartTag

protected int doStartTag(Writer out)
                  throws JspException,
IOException

Once the out JspWriter has been replaced to output the proper content type, this version of doStartTag() is called.

Parameters:

out - When the output type is null, will throw an exception if anything written, otherwise validates all characters against the output type. Already optimized via Coercion.optimize(java.io.Writer, com.aoapps.lang.io.Encoder).

Returns:

Must return either BodyTag.EVAL_BODY_BUFFERED (the default) or Tag.SKIP_BODY

Throws:

JspException

IOException

doInitBody

public void doInitBody()
                throws JspException

The only way to replace the "out" variable in the generated JSP is to use BodyTag.EVAL_BODY_BUFFERED. Without this, any writer given to JspContext.pushBody(java.io.Writer) is not used. We want to use NullWriter to discard data on-the-fly.

To workaround this issue, this very hackily replaces the writer field directly on the BodyContentImpl. When unable to replace the field, falls back to using the standard buffering (much less desirable).

This is similar to the direct field access performed by BodyContentImplCoercionOptimizerInitializer.

Specified by:

doInitBody in interface BodyTag

Overrides:

doInitBody in class BodyTagSupport

Throws:

JspException

doAfterBody

@Deprecated
public int doAfterBody()
                throws JspException

Deprecated.

You should probably be implementing in doAfterBody(java.io.Writer)

Specified by:

doAfterBody in interface IterationTag

Overrides:

doAfterBody in class BodyTagSupport

Throws:

JspException

See Also:

• doAfterBody(java.io.Writer)

doAfterBody

protected int doAfterBody(Writer out)
                   throws JspException,
IOException

While the out JspWriter is still replaced to output the proper content type, this version of doAfterBody() is called.

Parameters:

out - When the output type is null, will throw an exception if anything written, otherwise validates all characters against the output type. Already optimized via Coercion.optimize(java.io.Writer, com.aoapps.lang.io.Encoder).

Returns:

Must return either Tag.SKIP_BODY (the default) or IterationTag.EVAL_BODY_AGAIN

Throws:

JspException

IOException

doEndTag

@Deprecated
public int doEndTag()
             throws JspException

Deprecated.

You should probably be implementing in doEndTag(java.io.Writer)

Specified by:

doEndTag in interface Tag

Overrides:

doEndTag in class BodyTagSupport

Throws:

JspException

See Also:

• doEndTag(java.io.Writer)

doEndTag

protected int doEndTag(Writer out)
                throws JspException,
IOException

While the out JspWriter is still replaced to output the proper content type, this version of doEndTag() is called.

Parameters:

out - When the output type is null, will throw an exception if anything written, otherwise validates all characters against the output type. Already optimized via Coercion.optimize(java.io.Writer, com.aoapps.lang.io.Encoder).

Returns:

Must return either Tag.EVAL_PAGE (the default) or Tag.SKIP_PAGE

Throws:

JspException

IOException

doCatch

public void doCatch(Throwable t)
             throws Throwable

Specified by:

doCatch in interface TryCatchFinally

Throws:

Throwable

doFinally

public void doFinally()

Specified by:

doFinally in interface TryCatchFinally

writePrefix

protected void writePrefix(MediaType containerType,
 Writer out)
                    throws JspException,
IOException

Writes any prefix in the container's media type. The output must be valid for the provided type. This will not be called when the initial output type is null.

This default implementation prints nothing.

Parameters:

out - Validates all characters against the container media type. Already optimized via Coercion.optimize(java.io.Writer, com.aoapps.lang.io.Encoder).

Throws:

JspException

IOException

See Also:

• getOutputType()

setMediaEncoderOptions

protected void setMediaEncoderOptions(MediaEncoder mediaEncoder)

Sets the media encoder options. This is how subclass tag attributes can effect the encoding.

writeEncoderPrefix

protected void writeEncoderPrefix(MediaEncoder mediaEncoder,
 Writer out)
                           throws JspException,
IOException

Parameters:

out - Validates all characters against the container media type. Already optimized via Coercion.optimize(java.io.Writer, com.aoapps.lang.io.Encoder).

Throws:

JspException

IOException

writeEncoderSuffix

protected void writeEncoderSuffix(MediaEncoder mediaEncoder,
 Writer out,
 boolean trim)
                           throws JspException,
IOException

Parameters:

out - Validates all characters against the container media type. Already optimized via Coercion.optimize(java.io.Writer, com.aoapps.lang.io.Encoder).

Throws:

JspException

IOException

writeSuffix

protected void writeSuffix(MediaType containerType,
 Writer out)
                    throws JspException,
IOException

Writes any suffix in the container's media type. The output must be valid for the provided type. This will not be called when the initial output type is null.

This default implementation prints nothing.

Parameters:

out - Validates all characters against the container media type. Already optimized via Coercion.optimize(java.io.Writer, com.aoapps.lang.io.Encoder).

Throws:

JspException

IOException

See Also:

• getOutputType()