Struts2 OGNL案例

时间：2024-10-17 19:37:09

一>>原始类型与包装类型

先定义两个实体类User和Address

User

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;

    }

}

Address

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;

    }

}

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。

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;

    }

}

核心配置：struts.xml

<?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>

result页面

<%@ 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>

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：

Struts2 OGNL案例

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

<%@ 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>

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

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;

    }

}

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

<%@ 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>

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

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;

    }

}

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

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;

    }

}

实体类

User

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;

    }

}

Address

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;

    }

}

struts.xml

<action name="showArrayAndListAction" class="cn.action.ShowArraysAndListAction">

        <result name="success">result.jsp</result>

        </action>

result.jsp

<%@ 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>

效果:

Struts2 OGNL案例

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