Obj PageContext null in a Custom Tag

Question

Hi Every body
I'm Mauricio and my problem is :
I did a Custom tag and when I invoke it the PageContext object in the tag is null, I don't know why.
Any suggestion about the reason of this problem, will be a great help.
The source of Custom tag is :
package expert.esecurity.tag;
import java.io.IOException;
import javax.servlet.ServletRequest;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.JspWriter;
import javax.servlet.jsp.PageContext;
import javax.servlet.jsp.tagext.TagSupport;
public class SE_TagDynamicAction extends TagSupport
private PageContext objPageContext;
private String sbClazz;
private String sbMethod;
public void setPageContext(PageContext objPageContext)
this.objPageContext = objPageContext;
public void setSbClazz(String sbClazz)
this.sbClazz = sbClazz;
public void setSbMethod(String sbMethod)
this.sbMethod = sbMethod;
public int doStartTag() throws JspException
try
if(objPageContext!=null){ //the obj objPageContext is null
JspWriter out = pageContext.getOut();
ServletRequest objServletRequest = pageContext.getRequest();
     //Do the functionality and print reult
     out.print( result );
else{
throw new JspException("Object pageContext of the SE_TagDynamicAction tag is null");
catch (BA_UTException objBA_UTException)
throw new JspException(objBA_UTException.getMessage());
catch (IOException objIOException)
throw new JspException(objIOException.getMessage());
return SKIP_BODY;
public int doEndTag()
return EVAL_PAGE;
}

Answer 1

Your setPageContext didn't make the context null, the context was never null. YOUR objPageContext, however, was null.
Did you notice that you were checking for the existing of YOUR objPageContext (i.e != null) yet you were pulling, however you were pulling the request and writers from the default pageContext:
try
if(objPageContext !=null){ //the obj objPageContext is null
JspWriter out = pageContext.getOut(); // See, you didn't use objPageContext.getOut();
ServletRequest objServletRequest = pageContext.getRequest();// or objPageContext.getRequest();
//Do the functionality and print reult
out.print( result );
else{
throw new JspException("Object pageContext of the SE_TagDynamicAction tag is null");
}The point is, the setPageContext method is not guaranteed to be invoked by the system, this is there so YOU can assign a different pageContext if necessary. Therefore the setPageContext method was never called (as you never explicitly called it) and therefore your objPageContext was null. BUT, the default pageContext class variable was NOT null.
HTH.