Struts2 OGNL案例

先定义两个实体类User和Address

User

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package cn.entity;

public class User { 
    private String name; 
    private int age;     
    private Address address;
    public Address getAddress() {
        return address;
    }
    public void setAddress(Address address) {
        this.address = address;
    }
    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;
    }

}
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Address

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package cn.entity;

public class Address {
    private String country; // 国家
    private String city; // 城市
    private String street; // 街道
    public String getCountry() {
        return country;
    }
    public void setCountry(String country) {
        this.country = country;
    }
    public String getCity() {
        return city;
    }
    public void setCity(String city) {
        this.city = city;
    }
    public String getStreet() {
        return street;
    }
    public void setStreet(String street) {
        this.street = street;
    }
}
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创建出一个action先创建出两个成员变量 然后在核心方法中实例化成员变量。

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package cn.action;

import cn.entity.Address;
import cn.entity.User;

import com.opensymphony.xwork2.ActionSupport;


public class ShowOriginalAndJavaBeanAction extends ActionSupport {
    private User user;
    private String message;
    public String execute(){
        setUser(new User());
        getUser().setName("jbit");
        getUser().setAge(23);
        Address address=new Address();
        address.setCountry("中国");
        address.setCity("北京");
        address.setStreet("长安街");
        getUser().setAddress(address);
        setMessage("展示原始类型和JavaBean");
        return SUCCESS;
    }
    public User getUser() {
        return user;
    }
    public void setUser(User user) {
        this.user = user;
    }
    public String getMessage() {
        return message;
    }
    public void setMessage(String message) {
        this.message = message;
    }
}
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核心配置：struts.xml

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<?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>
<package name="default" extends="struts-default"> 
<action name="showOriginalAndJavaBeanAction" class="cn.action.ShowOriginalAndJavaBeanAction">
<result>result.jsp</result>
</action>
</package>
</struts>
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result页面

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<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@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>
    <base href="<%=basePath%>">
    
    <title>My JSP 'result.jsp' starting page</title>
    


  </head>
  
  <body>
       信息：<s:property value="message" default="展示数据" /><br/>
       姓名：<s:property value="user.name" /><br/>
       年龄：<s:property value="user.age"  /><br/>
      国家：<s:property value="user.address.country" />
    <s:debug></s:debug>
  </body>
</html>
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property标签用于输出ValueStack中对象属性的值，其中value属性用来指定要输出对象的属性，如果没有value属性，则默认输出ValueStack栈顶的对象，类型为Object；default属性是属性值为空时默认的默认值，类型为String

效果展示：

二>>多值类型请求参数的处理

如果在请求中出现多个值对应同一个请求参数的情况，Struts2会将这样的数据转换为面向集合的数据类型，如集合，数组

  1.数组

表单代码

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<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@taglib prefix="s" uri="/struts-tags" %>
<%
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 'index.jsp' starting page</title>

  </head>
  
  <body>
    <s:form action="ArraysDataTransfer.action">
        <s:textfield name="hobbies" label="爱好："/>
        <s:textfield name="hobbies" label="爱好："/>
        <s:textfield name="hobbies" label="爱好："/>
        
        <s:textfield name="numbers[0]" label="数字："/>
        <s:textfield name="numbers[1]" label="数字："/>
        <s:textfield name="numbers[2]" label="数字："/>
        <s:submit value="提交"/>
    </s:form>
  </body>
</html>
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第一个数组属性是hobbies，接收提交的爱好信息；第二个数组属性是numbers，接收提交的数字，如果数据转移要正常工作，这些属性必须存在ValueStack中。在Action类中公开这些属性

ArraysDataTransferAction

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package cn.action;

import com.opensymphony.xwork2.ActionSupport;

public class ArraysDataTransferAction extends ActionSupport {
    private String[] hobbies;
    private Double[] numbers=new Double[3];
    
    public String execute(){
        System.out.println("hobbies的长度是"+hobbies.length);
        for(int i=0;i<hobbies.length;i++){
            System.out.println("hobbies数组中第"+i+"个元素是："+hobbies[i]);
        }
        System.out.println("numbers的长度是"+numbers.length);
        for(int i=0;i<numbers.length;i++){
            System.out.println("numbers数组中第"+i+"个元素是："+numbers[i]);
        }
        
        return SUCCESS;
    }
    public String[] getHobbies() {
        return hobbies;
    }
    public void setHobbies(String[] hobbies) {
        this.hobbies = hobbies;
    }
    public Double[] getNumbers() {
        return numbers;
    }
    public void setNumbers(Double[] numbers) {
        this.numbers = numbers;
    }
}
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struts.xml

<action name="ArraysDataTransfer" class="cn.action.ArraysDataTransferAction">
            <result name="success">result2.jsp</result>
        </action>

result2.jsp

  <body>
       请查看控制台的输出
  </body>

2.集合

使用List与使用数组几乎相同，仅有不同的是集合类型可以借助泛型实现

表单代码

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<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@taglib prefix="s" uri="/struts-tags" %>
<%
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 'index.jsp' starting page</title>
    
  </head>
  
  <body>
    <s:form action="listDataTransfer">
        <s:textfield name="hobbies" label="爱好："/>
        <s:textfield name="hobbies" label="爱好："/>
        <s:textfield name="hobbies" label="爱好："/>
        
        <s:textfield name="numbers[0]" label="数字："/>
        <s:textfield name="numbers[1]" label="数字："/>
        <s:textfield name="numbers[2]" label="数字："/>
        
        <s:textfield name="users.name" label="姓名："/>
        <s:textfield name="users.name" label="姓名："/>
        <s:textfield name="users.name" label="姓名："/>
        <s:submit value="提交"/>
    </s:form>
  </body>
</html>
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相同名称参数有多个数据输入，可以将具有相同名称的参数看作一个集合，特殊说明的是users.name，当ognl解析这个表达式时，会首先定位user属性，与之不同的是，user是一个指定了元素为User对象的List。

ListDataTransferAction

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package cn.action;

import com.opensymphony.xwork2.ActionSupport;

import cn.entity.User;

import java.util.*;

public class ListDataTransferAction extends ActionSupport {
    private List<String> hobbies;
    private List<Double> numbers;
    private List<User> users;
    
    public String execute(){
        System.out.println("hobbies的长度是"+hobbies.size());
        for(int i=0;i<hobbies.size();i++){
            System.out.println("hobbies数组中第"+i+"个元素是："+hobbies.get(i));
        }
        System.out.println("numbers的长度是"+numbers.size());
        for(int i=0;i<numbers.size();i++){
            System.out.println("numbers数组中第"+i+"个元素是："+numbers.get(i));
        }
        System.out.println("users的长度是"+users.size());
        for(int i=0;i<users.size();i++){
            System.out.println("users数组中第"+i+"个元素是："+users.get(i).getName());
        }
        return SUCCESS;
    }
    public List<String> getHobbies() {
        return hobbies;
    }
    public void setHobbies(List<String> hobbies) {
        this.hobbies = hobbies;
    }
    public List<Double> getNumbers() {
        return numbers;
    }
    public void setNumbers(List<Double> numbers) {
        this.numbers = numbers;
    }
    public List<User> getUsers() {
        return users;
    }
    public void setUsers(List<User> users) {
        this.users = users;
    }

}
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struts.xml

<action name="listDataTransfer" class="cn.action.ListDataTransferAction">
            <result>result2.jsp</result>
        </action>

result2.jsp

  <body>
       请查看控制台的输出
  </body>

三>>访问集合对象

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package cn.action;

import java.util.ArrayList;
import java.util.List;

import cn.entity.Address;
import cn.entity.User;

import com.opensymphony.xwork2.ActionSupport;

public class ShowArraysAndListAction extends ActionSupport {
    
    private String[] hobbies;
    private List<Double> numbers;
    private List<User> users;
    


    private User user;
    
    
    
    public String execute() throws Exception {
        users=new ArrayList<User>();
        user=new User();
        user.setUsername("火狐");
        user.setPassword("11");
        Address address=new Address();
        address.setCountry("中国");
        address.setCity("北京");
        address.setStreet("长安街");
        user.setAddress(address);
        users.add(user);
        user=new User();
        user.setUsername("hh");
        user.setPassword("10");
        Address address2=new Address();
        address2.setCountry("中国");
        address2.setCity("北京");
        address2.setStreet("海淀");
        user.setAddress(address);
        users.add(user);
        return SUCCESS;
        
    }
    
    public String[] getHobbies() {
        return hobbies;
    }

    public void setHobbies(String[] hobbies) {
        this.hobbies = hobbies;
    }

    public List<Double> getNumbers() {
        return numbers;
    }

    public void setNumbers(List<Double> numbers) {
        this.numbers = numbers;
    }

    public List<User> getUsers() {
        return users;
    }

    public void setUsers(List<User> users) {
        this.users = users;
    }

}
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实体类

User

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package cn.entity;

public class User {
    //用户输入的姓名
    private String username;
    //用户输入的密码
    private String password;
    
    private Address address;
    public Address getAddress() {
        return address;
    }
    public void setAddress(Address address) {
        this.address = address;
    }
    /*
     * 获取名字
     * @return 名字
     */
    public String getUsername() {
        return username;
    }
    /*
     * 设置名字
     * @para name名字
     */
    public void setUsername(String username) {
        this.username = username;
    }
    
    /*
     * 获取密码
     * @return 密码
     */
    public String getPassword() {
        return password;
    }
    
    /*
     * 设置密码
     * @para password密码
     */
    public void setPassword(String password) {
        this.password = password;
    }
    
}
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Address

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package cn.entity;

public class Address {
    private String country; // 国家
    private String city; // 城市
    private String street; // 街道
    public String getCountry() {
        return country;
    }
    public void setCountry(String country) {
        this.country = country;
    }
    public String getCity() {
        return city;
    }
    public void setCity(String city) {
        this.city = city;
    }
    public String getStreet() {
        return street;
    }
    public void setStreet(String street) {
        this.street = street;
    }
}
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struts.xml

<action name="showArrayAndListAction" class="cn.action.ShowArraysAndListAction">
        <result name="success">result.jsp</result>
        </action>

result.jsp

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<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%
    String path = request.getContextPath();
    String basePath = request.getScheme() + "://"
            + request.getServerName() + ":" + request.getServerPort()
            + path + "/";
%>
<%@ taglib uri="/struts-tags" prefix="s"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">

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


</head>

<body>
     迭代数组输出：<br/>
    <s:iterator value="hobbies">
        <s:property /><br/>
    </s:iterator>
    迭代集合（元素类型为Double）：<br/>

<s:iterator value="numbers">
    <s:property /><br/>
</s:iterator>

迭代集合（元素类型为User）：<br/>


    <s:iterator value="users">
               用户名:<s:property value="username" /><br />
               密码:<s:property value="password" /><br />
               国家:<s:property value="address.country" /><br />
    </s:iterator>

    <s:debug></s:debug>
</body>
</html>
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效果:

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原文地址：https://www.cnblogs.com/6zhi/p/5946433.html