doAfterBody() is not executed using BodyTagSupport

[Gowher Naik]

package mapping.com.web;
import javax.servlet.jsp.*;
import javax.servlet.jsp.tagext.*;
import java.io.*;
public class CTag extends BodyTagSupport{
BodyContent bodyContent;
public int doStartTag()throws JspException{
try{
this.pageContext.getOut().print("doStartTag()");
}catch(Exception e){
e.printStackTrace();
}
return BodyTag.EVAL_BODY_BUFFERED;
}
public void setBodyContent(BodyContent bodyContent) {
      this.bodyContent = bodyContent;
      try{
this.pageContext.getOut().print("setBodyContent()");
}catch(Exception e){
e.printStackTrace();
}
    }
   public void doInitBody() throws JspException {
try{
this.pageContext.getOut().print("doInitBody()");
}catch(Exception e){
e.printStackTrace();
}
}
public int doAfterBody()throws JspException{
try{  
pageContext.getOut().print("doAfterBody()");
} catch(IOException ioe) {
throw new JspException(ioe.getMessage());
} 
  return Tag.SKIP_BODY;
}
public int doEndTag()throws JspException{
try{  
pageContext.getOut().print("doEndTag()");
} catch(IOException ioe) {
throw new JspException(ioe.getMessage());
} 
return Tag.EVAL_PAGE;
}
}

In TLD
<body-content>scriptless</body-content>

In jsp i using tag as shown below
[code]
<mine:classic >
body of tag
</mine:classic >
[code]

Output is
doStartTag()doEndTag()

Above CTag class extends BodyTagSupport.
In above class doAfterBody() is not executed.i dont know why.

Please Help
Thanks

[Sreeraj G Harilal]

change the doAfterBody() to :-

   
public int doAfterBody()throws JspException{
try{  
JspWriter out = bodyContent.getEnclosingWriter();
String str = bodyContent.getString();
out.print(str);
out.print("doAfterBody()");

} catch(IOException ioe) {
throw new JspException(ioe.getMessage());
} 
  return Tag.SKIP_BODY;
}
 

However, if doStartTag() returns EVAL_BODY_BUFFERED, the JSP container
takes a different course of action. It first creates an instance of the BodyContent
class. The BodyContent class is a subclass of JspWriter and overrides all
the print and write methods of JspWriter to buffer any data written into it rather
than sending it to the output stream of the response. The JSP container passes the
newly created BodyContent instance to the tag handler using its setBodyContent()
method, calls doInitBody() on the tag, and finally evaluates the body of
the tag, filling the BodyContent buffer with the result of the body tag evaluation.

[Sayak Banerjee]

nice bit of info....

[Sayak Banerjee]

Also, needed one clarification....can't you use bodyContent.print() directly instead of
JspWriter out = bodyContent.getEnclosingWriter();
out.print();
I came across the former one in Mikalai Zaikin's notes...awaiting your reply!!!

[Sreeraj G Harilal]

Check this

 
 
public int doAfterBody()throws JspException{
try{  

bodyContent.print("My Name is Sreeraj.G.H");
bodyContent.print("I am preparing for SCWCD");
JspWriter out = bodyContent.getEnclosingWriter();
String str = bodyContent.getString();
out.print(str);
out.print("doAfterBody()");

} catch(IOException ioe) {
throw new JspException(ioe.getMessage());
} 
  return Tag.SKIP_BODY;
}
 

Every thing we write using JspWriter will be buffered to BodyContent.
So we must use JspWriter out = bodyContent.getEnclosingWriter() to write something to the output.

[Sayak Banerjee]

Yes Sreeraj...but if you replace the whole class with the one given below, it still works...that's what I was tryin' to say......please check this as well...you can try it out...

package mapping.com.web;
import javax.servlet.jsp.*;
import javax.servlet.jsp.tagext.*;
import java.io.*;
 
public class TestBody extends BodyTagSupport {
public int doStartTag() throws JspException {
try {
pageContext.getOut().print("doStartTag()");
return EVAL_BODY_BUFFERED;
} catch(IOException ioe) {
throw new JspException(ioe.getMessage());
}
}
public void doInitBody() throws JspException {
try {
// Note, that this is a different writer than the one
// you have in doStartTag and doEndTag.
bodyContent.print("doInitBody()");
} catch(IOException ioe) {
throw new JspException(ioe.getMessage());
}
}
public int doAfterBody() throws JspException {
try {
// Note, that this is a different writer than the one
// you have in doStartTag and doEndTag.
bodyContent.print("doAfterBody()");
// return IterationTag.EVAL_BODY_AGAIN;
// Use this to loop
return SKIP_BODY;
} catch(IOException ioe) {
throw new JspException(ioe.getMessage());
}
}
public int doEndTag() throws JspException {
try {
// Write from bodyContent writer to original writer.
pageContext.getOut().print(bodyContent.getString());
// Now we're back to the original writer.
pageContext.getOut().print("doEndTag()");
return EVAL_PAGE;
} catch(IOException ioe) {
throw new JspException(ioe.getMessage());
}
}
}

Also, I didn't understand one thing....despite the BodyTagSupport class providing an implicit bodyContent field, why did Gowher add one explicitly to hide the implicit one...I don't find any significant reason
[ December 09, 2006: Message edited by: Sayak Banerjee ]

[Sreeraj Harilal]

Sayak i didn't get your question.

[Sayak Banerjee]

My question was whether it's really required to get an output stream by calling getEnclosingWriter() on the bodyContent object just for the purpose of sending the data to the output stream of the response....I mean you could just do it using bodyContent.print() from doAfterBody() or doInitBody()(as shown in the code shown by me above)....the starter of the thread just wanted to achieve this I guess
[ December 09, 2006: Message edited by: Sayak Banerjee ]

[Sreeraj G Harilal]

Did you checck the output?
What is the output of your code?
Please wright it down here.

[Sayak Banerjee]

OUTPUT : doStartTag()doInitBody() !!body of tag!! doAfterBody()doEndTag()

In jsp i using tag as shown below

<mine:classic >
!!body of tag!! 
</mine:classic >

[ December 10, 2006: Message edited by: Sayak Banerjee ]

[Sreeraj G Harilal]

Sayak, i am also confused. Let me try it out.

If anyone knows please give us a clear picture.