struts2标签

1. struts2标签
   

Struts2自己封装了一套标签，比JSTL强大，而且与Struts2中的其他功能无缝结合。
当然Strust2标签的内容很多，随着版本的升级，标签和属性越来越多。我们要掌握好核心标签及了解其他标签；
根据功能可以分为：数据标签，控制标签，界面标签，其他标签；

新建项目HeadFirstStruts2Chap05

MyComparator.java

package com.andrew.comparator;
import java.util.Comparator;
import com.andrew.model.Student;
public class MyComparator implements Comparator<Student> {
    public int compare(Student s1, Student s2) {
        if (s1.getAge() > s2.getAge()) {
            return 1;
        } else if (s1.getAge() < s2.getAge()) {
            return -1;
        }
        return 0;
    }
}

Student.java

package com.andrew.model;
public class Student {
    private int id;
    private String name;
    private int age;
    public Student() {}
    public Student(int id, String name, int age) {
        this.id = id;
        this.name = name;
        this.age = age;
    }
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
}

struts.xml

<package name="manage" namespace="/" extends="struts-default"></package>

jsp

<%@taglib prefix="s" uri="/struts-tags" %>

2. Struts2数据标签

1) property标签：输出OGNL表达式的值

<% request.setAttribute("name","<font color=red>张三</font>"); %>
<s:property value="#request.name" /><br/>
<s:property value="#request.name2" default="某某人"/><br/>
<s:property value="#request.name" default="某某人" escapeHtml="false"/><br/>

http://localhost:8080/HeadFirstStruts2Chap05/data/property.jsp
<font color=red>张三</font>
某某人
张三

2) set标签：设置变量

<s:set var="i" value="1"></s:set>
<s:property value="#i" /><br/>
<s:set var="a"  value="'action范围的值'" scope="action"></s:set>
<s:set var="p"  value="'page范围的值'" scope="page"></s:set>
<s:set var="r"  value="'request范围的值'" scope="request"></s:set>
<s:set var="s"  value="'session范围的值'" scope="session"></s:set>
<s:set var="app"  value="'application范围的值'" scope="application"></s:set>
<s:property value="#a" /><br/>
<s:property value="#attr.p"/><br/>
<s:property value="#request.r"/><br/>
<s:property value="#session.s"/><br/>
<s:property value="#application.app"/><br/>

http://localhost:8080/HeadFirstStruts2Chap05/data/set.jsp
1
action范围的值
page范围的值
request范围的值
session范围的值
application范围的值

3) bean标签：定义javaBean对象

<s:bean name="com.andrew.model.Student" var="student">
    <s:param name="name" value="'张三'"></s:param>
    <s:param name="age" value="10"></s:param>
</s:bean> 
<s:property value="#student.name"/>
<s:property value="#student.age"/>

http://localhost:8080/HeadFirstStruts2Chap05/data/bean.jsp
张三 10

4) date标签：日期标签

<%    request.setAttribute("date",new Date()); %>
${date }<br/>
当前日期：<s:date name="#request.date" format="yyyy-MM-dd"/>

http://localhost:8080/HeadFirstStruts2Chap05/data/date.jsp
Sat Jan 05 15:44:04 CST 2018
当前日期：2018-01-05

5) debug标签：调试标签

<s:debug></s:debug>

6) url&a标签：超链接标签

<s:url action="hello" namespace="/foreground" id="h">
    <s:param name="name" value="'struts2'"></s:param>
</s:url>
<s:a href="%{h}">超链接</s:a>
<s:a action="hello" namespace="/foreground">
    <s:param name="name" value="'struts2'"></s:param>
    超链接2
</s:a>

http://localhost:8080/HeadFirstStruts2Chap05/foreground/hello.action?name=struts2
http://localhost:8080/HeadFirstStruts2Chap05/foreground/hello.action?name=struts2

7) include标签：动态包含标签

<s:include value="head.html"></s:include>

head.html

头部

http://localhost:8080/HeadFirstStruts2Chap05/data/include.jsp
头部

3.  Struts2控制标签

1) ifelse标签：条件判断标签

<%    int age=11;
    request.setAttribute("age",age); %>
<s:if test="#request.age<20">年龄小于20岁</s:if>
<s:elseif test="#request.age==20">年龄等于20岁</s:elseif>
<s:else>年龄大于20岁</s:else>

年龄小于20岁 

2) iterator标签：遍历标签

<%@ page import="com.andrew.model.Student" %>
<%@ page import="java.util.*" %>
<%
    List<Student> studentList=new ArrayList<Student>();
    studentList.add(new Student(1,"张三",10));
    studentList.add(new Student(3,"李四",20));
    studentList.add(new Student(5,"王五",30));
    request.setAttribute("studentList",studentList);
%>
<table>
    <tr><th>序号</th><th>编号</th><th>姓名</th><th>年龄</th></tr>
    <s:iterator value="#request.studentList" status="status">
    <tr>
        <td><s:property value="#status.index+1"/></td>
        <td><s:property value="id"/></td>
        <td><s:property value="name"/></td>
        <td><s:property value="age"/></td>
    </tr>
    </s:iterator>
</table>

http://localhost:8080/HeadFirstStruts2Chap05/control/iterator.jsp
序号 编号 姓名 年龄
1 1 张三 10 
2 3 李四 20 
3 5 王五 30

3) append标签：叠加标签

<%@ page import="com.andrew.model.Student" %>
<%@ page import="java.util.*" %>
<%
    List<Student> studentList1=new ArrayList<Student>();
    List<Student> studentList2=new ArrayList<Student>();
    studentList1.add(new Student(1,"张三",10));
    studentList1.add(new Student(3,"李四",20));
    studentList2.add(new Student(5,"王五",30));
    studentList2.add(new Student(7,"赵六",40));
    request.setAttribute("studentList1",studentList1);
    request.setAttribute("studentList2",studentList2);
%>
<s:append var="studentList3">
    <s:param value="#request.studentList1"></s:param>
    <s:param value="#request.studentList2"></s:param>
</s:append>
<table>
    <tr><th>序号</th><th>编号</th><th>姓名</th><th>年龄</th></tr>
    <s:iterator value="studentList3" status="status">
    <tr>
        <td><s:property value="#status.index+1"/></td>
        <td><s:property value="id"/></td>
        <td><s:property value="name"/></td>
        <td><s:property value="age"/></td>
    </tr>
    </s:iterator>
</table>

http://localhost:8080/HeadFirstStruts2Chap05/control/append.jsp
序号 编号 姓名 年龄
1 1 张三 10 
2 3 李四 20 
3 5 王五 30 
4 7 赵六 40

4) generator标签：分隔标签

<s:generator separator="," val="'张三,李四,王五'" var="nameList"></s:generator>
<s:iterator value="#nameList">
    <s:property/>
</s:iterator>

http://localhost:8080/HeadFirstStruts2Chap05/control/generator.jsp
张三 李四 王五

5) merge标签：组合标签

<%@ page import="com.andrew.model.Student" %>
<%@ page import="java.util.*" %>
<%
    List<Student> studentList1=new ArrayList<Student>();
    List<Student> studentList2=new ArrayList<Student>();
    studentList1.add(new Student(1,"张三",10));
    studentList1.add(new Student(3,"李四",20));
    studentList2.add(new Student(5,"王五",30));
    studentList2.add(new Student(7,"赵六",40));
    request.setAttribute("studentList1",studentList1);
    request.setAttribute("studentList2",studentList2);
%>
<s:merge var="studentList3">
    <s:param value="#request.studentList1"></s:param>
    <s:param value="#request.studentList2"></s:param>
</s:merge>
<table>
    <tr><th>序号</th><th>编号</th><th>姓名</th><th>年龄</th></tr>
    <s:iterator value="studentList3" status="status">
    <tr>
        <td><s:property value="#status.index+1"/></td>
        <td><s:property value="id"/></td>
        <td><s:property value="name"/></td>
        <td><s:property value="age"/></td>
    </tr>
    </s:iterator>
</table>

http://localhost:8080/HeadFirstStruts2Chap05/control/merge.jsp
序号 编号 姓名 年龄
1 1 张三 10 
2 5 王五 30 
3 3 李四 20 
4 7 赵六 40 

6) sort标签：排序标签

<%@ page import="com.andrew.model.Student" %>
<%@ page import="java.util.*" %>
<%
    List<Student> studentList1=new ArrayList<Student>();
    studentList1.add(new Student(1,"张三",20));
    studentList1.add(new Student(3,"李四",10));
    studentList1.add(new Student(5,"王五",40));
    studentList1.add(new Student(7,"赵六",30));
    request.setAttribute("studentList1",studentList1);
%>
<s:bean id="myComparator" name="com.andrew.comparator.MyComparator"></s:bean>
<table>
    <tr><th>序号</th><th>编号</th><th>姓名</th><th>年龄</th></tr>
    <s:sort comparator="#myComparator" source="#request.studentList1" >
    <s:iterator status="status">
    <tr>
        <td><s:property value="#status.index+1"/></td>
        <td><s:property value="id"/></td>
        <td><s:property value="name"/></td>
        <td><s:property value="age"/></td>
    </tr>
    </s:iterator>
    </s:sort>
</table>

http://localhost:8080/HeadFirstStruts2Chap05/control/sort.jsp
序号 编号 姓名 年龄
1 3 李四 10 
2 1 张三 20 
3 7 赵六 30 
4 5 王五 40

7) subset标签：截取标签

<%@ page import="com.andrew.model.Student" %>
<%@ page import="java.util.*" %>
<%
    List<Student> studentList1=new ArrayList<Student>();
    studentList1.add(new Student(1,"张三",20));
    studentList1.add(new Student(3,"李四",10));
    studentList1.add(new Student(5,"王五",40));
    studentList1.add(new Student(7,"赵六",30));
    request.setAttribute("studentList1",studentList1);
%>
<table>
    <tr><th>序号</th><th>编号</th><th>姓名</th><th>年龄</th></tr>
    <s:subset source="#request.studentList1" count="2" start="2">
    <s:iterator status="status">
    <tr>
        <td><s:property value="#status.index+1"/></td>
        <td><s:property value="id"/></td>
        <td><s:property value="name"/></td>
        <td><s:property value="age"/></td>
    </tr>
    </s:iterator>
    </s:subset>
</table>

http://localhost:8080/HeadFirstStruts2Chap05/control/subset.jsp
序号 编号 姓名 年龄
1 5 王五 40 
2 7 赵六 30 

4. Strut2界面标签

1) form标签：表单提交标签

<s:form action="hello" method="post" namespace="/foreground"></s:form>

http://localhost:8080/HeadFirstStruts2Chap05/ui/form.jsp

2) text标签：文本标签

用户名：<s:textfield name="userName"></s:textfield><br/>
密码：<s:password name="password"></s:password><br/>
备注：<s:textarea name="desc"></s:textarea><br/>

http://localhost:8080/HeadFirstStruts2Chap05/ui/text.jsp

3) radios标签：单选标签

性别：<s:radio list="#{0: '男 ', 1:'女 '}" name="sex" value="0" />

http://localhost:8080/HeadFirstStruts2Chap05/ui/radio.jsp

4) checkboxlist标签：复选框标签

爱好：<s:checkboxlist list="#{0: '游泳', 1:'唱歌 ',2:'跳舞'}" name="hobby" value="1" />

http://localhost:8080/HeadFirstStruts2Chap05/ui/checkbox.jsp

5) select标签：下拉框标签

爱好：<s:select list="#{0: '游泳', 1:'唱歌 ',2:'跳舞'}" name="hobby" value="1" multiple="true"/>

http://localhost:8080/HeadFirstStruts2Chap05/ui/select.jsp

5. 其他标签

1) updownselect标签

<s:updownselect 
    list="#{0:'游泳', 1:'唱歌', 2:'跳舞'}"
    name="hobby" 
    headerKey="-1"
    headerValue="请选择" 
    emptyOption="true"
    allowMoveUp="true" 
    allowMoveDown="true" 
    allowSelectAll="true"
    moveUpLabel="向上" 
    moveDownLabel="向下"
    selectAllLabel="全选" /> 

http://localhost:8080/HeadFirstStruts2Chap05/ui/updownselect.jsp

2) optiontransferselect标签

<s:optiontransferselect label="选择你喜欢图书"  
              name="cnbook" leftTitle="中文图书"  list="{'struts2权威指南','轻量级javaeye 企业应用空实战','ajax讲义'}"
              doubleName="enBook"  rightTitle="外文图书" doubleList="{'JavaScrip:The definitive Guide','export one-to-one'}"  multiple="true" 
              addToLeftLabel="向左移动" addToRightLabel="向右移动" addAllToRightLabel="全部右移" addAllToLeftLabel="全部左移"
               allowSelectAll="true" headerKey="cnKey" headerValue="选择图书" emptyOption="true"   doubleHeaderKey="enKey" 
               doubleHeaderValue="选择外文图书" doubleMultiple="true" doubleEmptyOption="true"  leftDownLabel="向下移动" 
       rightDownLabel="向下移动" 
       leftUpLabel="向上移动" 
       rightUpLabel="向上移动" >
   </s:optiontransferselect>

http://localhost:8080/HeadFirstStruts2Chap05/ui/optiontransferselect.jsp