自定义标签库读取list输出-优快云博客

本文链接：https://blog.youkuaiyun.com/iteye_18341/article/details/82584292

jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib uri="http://www.cgmcc.com/jsp/mylist" prefix="my5" %>

<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">

<title>My JSP 'list.jsp' starting page</title>

<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">


</head>

<body>
<%
List list=new ArrayList();
list.add("aaaa");
list.add("sss");
list.add("ddd");
list.add("fff");
request.setAttribute("listObj",list);
%>
<hr>

<%
List list1=(List)request.getAttribute("listObj");
Iterator iterator=list1.iterator();
while(iterator.hasNext()){
String str=(String)iterator.next();
request.setAttribute("strstr",str);

%>
${strstr} <br>
<%
}
%>
<hr/>

<my5:myList items="${listObj}" var="yyyy" >
${yyyy} ##<br/>
</my5:myList>
</body>
</html>

java
package com.cgm.tlist;

import java.io.IOException;
import java.util.Iterator;
import java.util.List;

import javax.servlet.jsp.JspContext;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.tagext.JspFragment;
import javax.servlet.jsp.tagext.JspTag;
import javax.servlet.jsp.tagext.SimpleTagSupport;

public class MyList extends SimpleTagSupport {
private List items;
private String var;

public List getItems() {
return items;
}

public void setItems(List items) {
this.items = items;
}

public String getVar() {
return var;
}

public void setVar(String var) {
this.var = var;
}

@Override
public void doTag() throws JspException, IOException {

System.out.println("============"+items);
System.out.println("-============="+var);

Iterator iterator =items.iterator();

while (iterator.hasNext()) {
String str=(String) iterator.next();
this.getJspContext().setAttribute(var, str);
this.getJspBody().invoke(null);

}

}

@Override
protected JspFragment getJspBody() {
// TODO Auto-generated method stub
return super.getJspBody();
}

@Override
protected JspContext getJspContext() {
// TODO Auto-generated method stub
return super.getJspContext();
}

@Override
public JspTag getParent() {
// TODO Auto-generated method stub
return super.getParent();
}

@Override
public void setJspBody(JspFragment jspBody) {
// TODO Auto-generated method stub
super.setJspBody(jspBody);
}

@Override
public void setJspContext(JspContext pc) {
// TODO Auto-generated method stub
super.setJspContext(pc);
}

@Override
public void setParent(JspTag parent) {
// TODO Auto-generated method stub
super.setParent(parent);
}

}

tld
<?xml version="1.0" encoding="UTF-8" ?>

<taglib xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-jsptaglibrary_2_0.xsd"
version="2.0">
<tlib-version>1.0</tlib-version>
<short-name>my5</short-name>
<uri>http://www.cgmcc.com/jsp/mylist</uri>



<tag>
<name>myList</name>
<tag-class>com.cgm.tlist.MyList</tag-class>
<body-content>scriptless</body-content>
<attribute>
<name>items</name>
<required>true</required>
<rtexprvalue>true</rtexprvalue>
</attribute>

<attribute>
<name>var</name>
<required>true</required>
<rtexprvalue>true</rtexprvalue>
</attribute>

</tag>

</taglib>