一、forEach遍历JSP的Map
BigCitiesServlet.java代码
package cays
.app05a
;
import javax
.servlet
.RequestDispatcher
;
import javax
.servlet
.ServletException
;
import javax
.servlet
.annotation
.WebServlet
;
import javax
.servlet
.http
.HttpServlet
;
import javax
.servlet
.http
.HttpServletRequest
;
import javax
.servlet
.http
.HttpServletResponse
;
import java
.io
.IOException
;
import java
.util
.HashMap
;
import java
.util
.Map
;
@WebServlet(name
= "BigCitiesServlet", urlPatterns
= "/bigCities")
public class BigCitiesServlet extends HttpServlet {
protected void doPost(HttpServletRequest request
, HttpServletResponse response
) throws ServletException
, IOException
{
}
protected void doGet(HttpServletRequest request
, HttpServletResponse response
) throws ServletException
, IOException
{
Map
<String,String> capitals
= new HashMap<>();
capitals
.put("Indonesia", "Jakarta");
capitals
.put("Mala", "Kuala");
capitals
.put("Thai", "Bank");
request
.setAttribute("capitals", capitals
);
Map
<String
, String
[]> bigCities
= new HashMap<>();
bigCities
.put("Australia", new String[]{"Sydney", "Melbourne", "Perth"});
bigCities
.put("New Zealand", new String[]{"Auckland", "Christchurch", "Wellington"});
bigCities
.put("Indonesia", new String[]{"Jakarta", "Surabaya", "Medan"});
request
.setAttribute("bigCities", bigCities
);
RequestDispatcher rd
= request
.getRequestDispatcher("/bigCities.jsp");
rd
.forward(request
, response
);
}
}
bigCities.jsp代码
<%--
Created by IntelliJ
IDEA.
User
: cays
Date
: 2019/5/22
Time
: 21:44
To change
this template use File
| Settings
| File Templates
.
--%>
<%@ page contentType
="text/html;charset=UTF-8" language
="java" %>
<%@ taglib prefix
="c" uri
="http://java.sun.com/jsp/jstl/core" %>
<html
>
<head
>
<title
>BigCitie
</title
>
<style
>
table
, tr
, td
{
border
: 1px solid #aaee77
;
padding
: 3px
;
}
</style
>
</head
>
<body
>
<%--
c
:forEach 标签访问map
--%>
Capitals
<table
>
<tr style
="background: #448755;color: white;font-weight: bold">
<td
>Country
</td
>
<td
>Capital
</td
>
</tr
>
<c
:forEach items
="${requestScope.capitals}" var="mapItem">
<tr
>
<td
>$
{mapItem
.key
}</td
>
<td
>$
{mapItem
.value
}</td
>
</tr
>
</c
:forEach
>
</table
>
Big Cities
<table
>
<tr style
="background: #448755;color: white;font-weight: bold">
<td
>Country
</td
>
<td
>Cities
</td
>
</tr
>
<c
:forEach items
="${requestScope.bigCities}" var="mapItem">
<tr
>
<td
>$
{mapItem
.key
}</td
>
<td
>
<c
:forEach items
="#{mapItem.value}" var="city" varStatus
="status">
$
{city
}<c
:if test
="${!status.last}">,</c
:if>
</c
:forEach
>
</td
>
</tr
>
</c
:forEach
>
</table
>
</body
>
</html
>
二、执行结果
