PutTag.java

package com.ziqewgww.tag;

import java.util.Hashtable;
import java.util.Stack;

import javax.servlet.jsp.JspException;
import javax.servlet.jsp.tagext.TagSupport;

public class PutTag extends TagSupport {
	   private String name, content, direct="false";
	   // setter methods for Put tag attributes
	   public void setName(String s) { name = s; }
	   public void setContent(String s) {content = s; }
	   public void setDirect(String s) { direct = s; }
	   public int doStartTag() throws JspException {
	      // obtain a reference to enclosing insert tag
	      InsertTag parent = (InsertTag)getAncestor(
	                              "com.ziqewgww.tag.InsertTag");
	      // put tags must be enclosed in an insert tag
	      if(parent == null)
	         throw new JspException("PutTag.doStartTag(): " +
	                                "No InsertTag ancestor");
	      // get template stack from insert tag
	      Stack template_stack = parent.getStack();
	      // template stack should never be null
	      if(template_stack == null)
	         throw new JspException("PutTag: no template stack");
	      // peek at hashtable on the stack
	      Hashtable params = (Hashtable)template_stack.peek();
	      // hashtable should never be null either
	      if(params == null)
	         throw new JspException("PutTag: no hashtable");
	      // put a new PageParameter in the hashtable
	      params.put(name, new PageParameter(content, direct));
	      return SKIP_BODY; // not interested in tag body, if present
	   }
	   // tag handlers should always implement release() because
	   // handlers can be reused by the JSP container
	   public void release() {
	      name = content = direct = null;
	   }
	   // convenience method for finding ancestor names with
	   // a specific class name
	   private TagSupport getAncestor(String className)
	                                 throws JspException {
	      Class klass = null; // can't name variable "class"
	      try {
	         klass = Class.forName(className);
	      }
	      catch(ClassNotFoundException ex) {
	         throw new JspException(ex.getMessage());
	      }
	      return (TagSupport)findAncestorWithClass(this, klass);
	   }
	}