---
title: "Java - Parameter tag"
type: "forum-thread"
url: "https://www.webforum.nu/amne/programmering/75161-java-parameter-tag"
topic: "Programmering"
topic_url: "https://www.webforum.nu/amne/programmering"
author: "Viktor"
published: "2003-04-27T08:58:32.000Z"
updated: "2003-04-27T08:58:32.000Z"
replies: 0
views: 1399
page: 1
pages: 1
language: "sv-SE"
site: "webForum — webforum.nu"
rights: "Upphovsrätten till varje inlägg tillhör dess författare."
attribution: "Citera som: webForum, https://www.webforum.nu/amne/programmering/75161-java-parameter-tag"
---

# Java - Parameter tag

## #1 — Viktor, 2003-04-27T08:58Z

Här är en tag som skriver ut en vald parameter från querystring, session eller page contexten.

```
package com.vgsoftware.vglib.util;

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

public class ParamTag extends TagSupport
{
	public String name=null;
	public String type=null;

	public int doEndTag()
	throws JspTagException
	{
		try
		{
			if(type==null||type.equals("query"))
				pageContext.getOut().print(pageContext.getRequest().getParameter(name));
			else if(type.equals("session"))
				pageContext.getOut().print(pageContext.getSession().getAttribute(name));
			else if(type.equals("page"))
				pageContext.getOut().print(pageContext.getAttribute(name));
		}
		catch(java.io.IOException io)
		{
			throw(new JspTagException(io.getMessage()));
		}
		return(EVAL_PAGE);
	}

	public void setType(String type)
	{
		this.type=type;
	}

	public String getType()
	{
		return(type);
	}

	public void setName(String name)
	{
		this.name=name;
	}

	public String getName()
	{
		return(name);
	}
}
```

TDL för taggen,

```
<?xml version="1.0"?>
<!DOCTYPE taglib PUBLIC	"-//Sun Microsystems, Inc.//DTD JSP Tag Library 1.1//EN"
"http://java.sun.com/j2ee/dtds/web-jsptaglibrary_1_1.dtd">
<taglib>
	<tlibversion>1.0</tlibversion>
	<jspversion>1.1</jspversion>
	<shortname>vglib</shortname>

	<info>
		
	</info>

	<tag>
		<name>param</name>
		<tagclass>com.vgsoftware.vglib.util.ParamTag</tagclass>
		<info></info>
		<attribute>
			<name>name</name>
			<required>true</required>
			<rtexprvalue>true</rtexprvalue>
		</attribute>
		<attribute>
			<!--
				Here you can set the type of variable that will be read.
				Default is from the querystring, but ok values here are
				query (querystring)
				session (session object)
				page (page context)
			-->
			<name>type</name>
			<required>false</required>
			<rtexprvalue>true</rtexprvalue>
		</attribute>
	</tag>
</taglib>
```

/Viktor

Permalänk: https://www.webforum.nu/p/75161

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Tråden på webben: https://www.webforum.nu/amne/programmering/75161-java-parameter-tag