使用c:forEach模擬s:select標籤
阿新 • • 發佈：2019-02-16
一、兩種實現方式的效果圖
二、關鍵部分的程式碼
Struts2方式
<s:select name="student.province" list="dictionary.provinceList" listKey="key" listValue="value"></s:select>JSTL方式
<select name="student.province"> <c:forEach items="${dictionary.provinceList }" var="list"> <option value="${list.key }">${list.value }</option> </c:forEach> </select>
三、完整步驟
1.程式碼結構
（1）配置檔案
web.xml,struts.xml
（2）相關jar包
位於目錄WebRoot/WEB-INF/lib目錄下
（3）後臺程式碼 com.compname包
action部分：StudentAction.java
po部分：SelectData.java（存放單個下拉列表的鍵和值）,Dictionary.java（將多個下拉列表封裝到一個實體類中）
（4）前端頁面相關
student_list.jsp,jquery-1.11.0.js
2.實現程式碼
（1）配置檔案
web.xml
struts.xml<?xml version="1.0" encoding="UTF-8"?> <web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"> <filter> <filter-name>struts2</filter-name> <filter-class> org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter </filter-class> </filter> <filter-mapping> <filter-name>struts2</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> </web-app>
（2）用到的jar包（需要Struts2和jstl的相應支援jar包）<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN" "http://struts.apache.org/dtds/struts-2.0.dtd"> <struts> <constant name="struts.ui.theme" value="simple" /> <package name="basicStruts" extends="struts-default" namespace="/studentMgmt"> <action name="initQueryPage" class="com.compname.action.StudentAction" method="initQueryPage"> <result name="success">/studentMgmt/student_list.jsp</result> </action> </package> </struts>
（3）後臺程式碼
StudentAction.java
package com.compname.action;
import java.util.ArrayList;
import java.util.List;
import com.compname.po.Dictionary;
import com.compname.po.SelectData;
public class StudentAction {
private Dictionary dictionary;
/**
* 初始化查詢頁面
*
* @return
*/
public String initQueryPage() {
dictionary = new Dictionary();
List<SelectData> list = new ArrayList<SelectData>();
list.add(new SelectData("1", "北京"));
list.add(new SelectData("2", "上海"));
list.add(new SelectData("3", "廣州"));
list.add(new SelectData("4", "深圳"));
list.add(new SelectData("5", "河北"));
list.add(new SelectData("6", "河南"));
list.add(new SelectData("7", "山西"));
list.add(new SelectData("8", "山東"));
list.add(new SelectData("9", "江蘇"));
list.add(new SelectData("10", "浙江"));
dictionary.setProvinceList(list);
return "success";
}
public Dictionary getDictionary() {
return dictionary;
}
public void setDictionary(Dictionary dictionary) {
this.dictionary = dictionary;
}
}
SelectData.java
package com.compname.po;
/**
*
* @ClassName: SelectData
* @Description: TODO(存放鍵值對)
* @date 2017-10-26 下午10:47:36
*/
public class SelectData {
private String key; // 鍵
private String value; // 值
public SelectData(String key, String value) {
super();
this.key = key;
this.value = value;
}
public String getKey() {
return key;
}
public void setKey(String key) {
this.key = key;
}
public String getValue() {
return value;
}
public void setValue(String value) {
this.value = value;
}
}package com.compname.po;
import java.util.ArrayList;
import java.util.List;
/**
*
* @ClassName: Dictionary
* @Description: TODO(用於存放所有的鍵值對資料)
* @date 2017-10-26 下午10:47:36
*/
public class Dictionary {
private transient List<SelectData> provinceList = new ArrayList<SelectData>();
public List<SelectData> getProvinceList() {
return provinceList;
}
public void setProvinceList(List<SelectData> provinceList) {
this.provinceList = provinceList;
}
}student_list.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<%@ taglib uri="/struts-tags" prefix="s"%>
<%
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>
<title>My JSP 'student_list.jsp' starting page</title>
<script type="text/javascript" src="<%=path%>/js/jquery/jquery-1.11.0.js"></script>
<style type="text/css">
table tr td {
border: 1px solid black;
}
</style>
</head>
<body>
<form action="">
<table>
<tr>
<td>struts2中的select標籤</td>
<td>使用jstl中的foreach模擬實現strusts2中的select標籤</td>
</tr>
<tr>
<td>
<s:select name="student.province" list="dictionary.provinceList" listKey="key" listValue="value"></s:select>
</td>
<td>
<select name="student.province">
<c:forEach items="${dictionary.provinceList }" var="list">
<option value="${list.key }">${list.value }</option>
</c:forEach>
</select>
</td>
</tr>
</table>
</form>
</body>
</html>說明：如果不想在struts.xml中全域性配置struts標籤的樣式（第6行）
<constant name="struts.ui.theme" value="simple" />（第29行）
<s:select name="student.province" list="dictionary.provinceList" listKey="key" listValue="value"></s:select>改成
<s:select name="student.province" list="dictionary.provinceList" listKey="key" listValue="value" theme="simple"></s:select>