（转）Spring3MVC 在JSP中使用@ModelAttribute

<?xml version="1.0" encoding="UTF-8"?>
<web-app id="WebApp_ID" version="2.4"
    xmlns="http://java.sun.com/xml/ns/j2ee" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee 
    http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">

    <servlet>
        <servlet-name>spring</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>

    <servlet-mapping>
        <servlet-name>spring</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

</web-app>

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"
    xsi:schemaLocation="http://www.springframework.org/schema/beans 
               http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">

    <!-- 定义一个视图解析器 -->
    <bean id="viewResolver"
        class="org.springframework.web.servlet.view.InternalResourceViewResolver"
        p:prefix="/WEB-INF/jsp/" p:suffix=".jsp" />

</beans>

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xsi:schemaLocation="http://www.springframework.org/schema/beans 
               http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
               http://www.springframework.org/schema/context
               http://www.springframework.org/schema/context/spring-context-3.0.xsd
            http://www.springframework.org/schema/mvc 
            http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd">

    <!-- 激活spring的注解. -->
    <context:annotation-config />

    <!-- 扫描注解组件并且自动的注入spring beans中. 
    例如,他会扫描org.liukai.tutorial下@Controller 和@Service下的文件.所以确保此base-package设置正确. -->
    <context:component-scan base-package="org.liukai.tutorial" />

    <!-- 配置注解驱动的Spring MVC Controller 的编程模型.注:此标签只在 Servlet MVC工作! -->
    <mvc:annotation-driven />

</beans>

package org.liukai.tutorial.domain;

import java.io.Serializable;

public class Address implements Serializable {

    private static final long serialVersionUID = -8889854671283221397L;

    private Integer id;
    private String street;
    private String zipCode;
    private String city;
 
         ......getter/setter
}

package org.liukai.tutorial.domain;

import java.io.Serializable;

public class Person implements Serializable {

    private static final long serialVersionUID = -8333984959652704635L;

    private Integer id;
    private String firstName;
    private String lastName;
    private String currency;
    private Double money;

  ......getter/setter

}

package org.liukai.tutorial.service;

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

import org.apache.log4j.Logger;
import org.liukai.tutorial.domain.Address;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

/**
 * 同样用于显示.
 * 
 * @author liukai
 * 
 */
@Service("addressService")
@Transactional
public class AddressService {

    protected static Logger logger = Logger.getLogger("service");

    /**
     * 获得所有的地址.
     * 
     * @return
     */
    public List<Address> getAll() {
        logger.debug("Retrieving all addresses");

        List<Address> addresses = new ArrayList<Address>();

        // New address
        Address address = new Address();
        address.setId(1);
        address.setStreet("1 Street");
        address.setCity("City 1");
        address.setZipCode("11111");

        // Add to list
        addresses.add(address);

        // New address
        address = new Address();
        address.setId(2);
        address.setStreet("2 Street");
        address.setCity("City 2");
        address.setZipCode("22222");

        // Add to list
        addresses.add(address);

        // New address
        address = new Address();
        address.setId(3);
        address.setStreet("3 Street");
        address.setCity("City 3");
        address.setZipCode("33333");

        // Add to list
        addresses.add(address);

        // Return all addresses
        return addresses;
    }

}

package org.liukai.tutorial.service;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.log4j.Logger;
import org.liukai.tutorial.domain.Person;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

/**
 * 注意这个只是一个临时数据用于显示.
 * 
 * @author liukai
 * 
 */
@Service("personService")
@Transactional
public class PersonService {

    protected static Logger logger = Logger.getLogger("service");

    private HashMap<Integer, Person> database = new HashMap<Integer, Person>();

    /**
     * Initialize a list of persons
     */
    private void init() {
        // New person
        Person person = new Person();
        person.setId(1);
        person.setFirstName("John");
        person.setLastName("Smith");
        person.setCurrency("Dollar");
        person.setMoney(1500.00);

        // Add to list
        database.put(1, person);

        // New person
        person = new Person();
        person.setId(2);
        person.setFirstName("Jane");
        person.setLastName("Adams");
        person.setCurrency("Yen");
        person.setMoney(1000.00);

        // Add to list
        database.put(2, person);

        // New person
        person = new Person();
        person.setId(3);
        person.setFirstName("Mike");
        person.setLastName("Polaski");
        person.setCurrency("Euro");
        person.setMoney(2000.00);

        // Add to list
        database.put(3, person);
    }

    public PersonService() {
        // Initialize dummy database
        init();
    }

    /**
     * 检索所有的 persons
     */
    public List<Person> getAll() {
        logger.debug("Retrieving all persons");

        // Initialize our array
        List<Person> persons = new ArrayList<Person>();

        // Iterate the database
        for (Map.Entry<Integer, Person> entry : database.entrySet()) {
            persons.add(entry.getValue());
        }

        // Return all persons
        return persons;
    }

    /**
     * 根据ID获得对应的Perosn
     */
    public Person get(Integer id) {
        logger.debug("Retrieving person based on his id");
        return database.get(id);
    }

    /**
     * 修改Person
     */
    public void edit(Person person) {
        logger.debug("Editing existing person");

        // Note this is not the best way to update a data!

        // Delete existing user
        database.remove(person.getId());
        // Add updated user
        database.put(person.getId(), person);
    }

}

package org.liukai.tutorial.controller;

import java.util.List;

import javax.annotation.Resource;

import org.apache.log4j.Logger;
import org.liukai.tutorial.domain.Address;
import org.liukai.tutorial.service.AddressService;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

@Controller
@RequestMapping("/address")
public class AddressController {

    protected static Logger logger = Logger.getLogger("controller");

    @Resource(name = "addressService")
    private AddressService addressService;

    /**
     * 获得所有Addresses,并使他们成为一个model. 
     * 注意@ModelAttribute作用于method级别上时.会在@Controller执行时加载
     * method里的方法.即在@Controller执行时@ModelAttribute添加参数.
     * 返回于该@Controller返回的所有JSP页面.
     */
    @ModelAttribute("addresses")
    public List<Address> getAllAddresses() {
        return addressService.getAll();
    }

    /**
     * 处理和检索一个包含addresses 的JSP Page .
     */
    @RequestMapping(value = "list1", method = RequestMethod.GET)
    public String getAllUsingModelAttribute() {
        logger.debug("Received request to show all addresses page");

        // 他会解析 /WEB-INF/jsp/addressespage.jsp
        return "addressespage";
    }

    /**
     * 处理和检索一个包含addresses 的JSP Page .
     * 
     * @return the name of the JSP page
     */
    @RequestMapping(value = "list2", method = RequestMethod.GET)
    public String getAllUsingModel(Model model) {
        logger.debug("Received request to show all addresses page");

        // 检索所有的address并装入model返回addressespage.jsp
        model.addAttribute("addresses", addressService.getAll());
        model.addAttribute("greetings", "I came from Model not ModelAttribute");

        // This will resolve to /WEB-INF/jsp/addressespage.jsp
        return "addressespage";
    }

}

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>

    <h1>Addresses</h1>

    <table>
        <tr>
            <td width="100">Id</td>
            <td width="150">Street</td>
            <td width="150">City</td>
            <td width="150">Zip Code</td>
        </tr>
        <c:forEach items="${addresses}" var="address">
            <tr>
                <td><c:out value="${address.id}" />
                </td>
                <td><c:out value="${address.street}" />
                </td>
                <td><c:out value="${address.city}" />
                </td>
                <td><c:out value="${address.zipCode}" />
                </td>
            </tr>
        </c:forEach>
    </table>

    <p>${greetings}</p>
</body>
</html>

package org.liukai.tutorial.controller;

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

import javax.annotation.Resource;

import org.apache.log4j.Logger;
import org.liukai.tutorial.domain.Person;
import org.liukai.tutorial.service.PersonService;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

@Controller
@RequestMapping("/main")
public class MainController {

    protected static Logger logger = Logger.getLogger("controller");

    @Resource(name = "personService")
    private PersonService personService;

    /**
     * 获得所有Person,并使他们成为一个model.
     */
    @ModelAttribute("persons")
    public List<Person> getAllPersons() {
        logger.debug("Retrieving all persons and adding it to ModelAttribute");
        // Delegate to PersonService
        return personService.getAll();
    }

    /**
     * 获得所有的货币类型,并使他们成为一个model.
     */
    @ModelAttribute("currencies")
    public List<String> getAllCurrencies() {
        logger.debug("Retrieving all currencies and adding it to ModelAttribute");

        // Prepare data
        List<String> currencies = new ArrayList<String>();
        currencies.add("Dollar");
        currencies.add("Yen");
        currencies.add("Pound");
        currencies.add("Euro");
        currencies.add("Dinar");

        return currencies;
    }

    /**
     * 处理和检索一个包含Perosn 的JSP Page
     */
    @RequestMapping(method = RequestMethod.GET)
    public String getAllPage(Model model) {

        logger.debug("Received request to show all persons page");

        // personsage.jsp会引用一个名叫persons的model attribute
        // 我们不需要手动添加这个model
        // 前面他已经自动的通过@ModelAttribute("persons")进行了添加.

        // 他会解析 /WEB-INF/jsp/personspage.jsp
        return "personspage";
    }

    /**
     * 检索修改页面
     */
    @RequestMapping(value = "/edit/{id}", method = RequestMethod.GET)
    public String getEdit(@PathVariable Integer id, Model model) {
        /*
         * @PathVariable表示指定@RequestMapping的URL模板中{}里的值 
         * 相当于以前我们URL后面传的参数如XX?id=XXXX .
         * 但是现在我们可以用 XX/id/XX来代替. 
         * 这个就是REST风格的URL,我们可以实现非常复杂的URL模板
         */

        logger.debug("Received request to show edit page");

        /*
         * 根据ID检索出对应的Person,然后把检索出来的Person放入一个叫
         * "personAttribute"的model中.
         * 这样editpage.jsp就会接收一个 名为personAttribute的参数.
         * 相当于request.setAttribute("XX",XX)
         */
        model.addAttribute("personAttribute", personService.get(id));

        // This will resolve to /WEB-INF/jsp/editpage.jsp
        return "editpage";
    }

    /**
     * 保存修改结果
     */
    @RequestMapping(value = "/edit/{id}", method = RequestMethod.POST)
    public String saveEdit(@ModelAttribute("personAttribute") Person person,
            @PathVariable Integer id, Model model) {
        logger.debug("Received request to update person");

        // 我们从页面接收到了一个名为"personAttribute"的model并命名为person
        // 同样我们也获得了指定的id.
        person.setId(id);

        // 更新person
        personService.edit(person);

        // 在更新后我们重新显示所有Person 的页面
        model.addAttribute("persons", personService.getAll());

        // This will resolve to /WEB-INF/jsp/personspage.jsp
        return "personspage";
    }

}

@RequestMapping(value = "/edit/{id}", method = RequestMethod.POST)
    public String saveEdit(@ModelAttribute("personAttribute") Person person, 
      @PathVariable Integer id, Model model) {
...
}

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>

<h1>Persons</h1>

<table>
    <tr>
        <td width="50">Id</td>
        <td width="150">First Name</td>
        <td width="150">Last Name</td>
        <td width="100">Money</td>
        <td width="50">Currency</td>
    </tr>
    <c:forEach items="${persons}" var="person">
        <tr>
            <td><c:out value="${person.id}" /></td>
            <td><c:out value="${person.firstName}" /></td>
            <td><c:out value="${person.lastName}" /></td>
            <td><c:out value="${person.money}" /></td>
            <td><c:out value="${person.currency}" /></td>
        </tr>
    </c:forEach>
</table>

</body>
</html>

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@ taglib uri="http://www.springframework.org/tags/form" prefix="form" %>
<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>

<h1>Edit Person</h1>

<c:url var="saveUrl" value="/main/edit/${personAttribute.id}" />

<form:form modelAttribute="personAttribute" method="POST" action="${saveUrl}">
    <table>
        <tr>
            <td><form:label path="id">Id:</form:label></td>
            <td><form:input path="id" disabled="true"/></td>
        </tr>
    
        <tr>
            <td><form:label path="firstName">First Name:</form:label></td>
            <td><form:input path="firstName"/></td>
        </tr>

        <tr>
            <td><form:label path="lastName">Last Name</form:label></td>
            <td><form:input path="lastName"/></td>
        </tr>
        
        <tr>
            <td><form:label path="money">Money</form:label></td>
            <td><form:input path="money"/></td>
        </tr>
        
        <tr>
            <td><form:label path="currency">Currency:</form:label></td>
            <td><form:select path="currency"  items="${currencies}"/></td>
        </tr>
    </table>
    
    <input type="submit" value="Save" />
</form:form>

</body>
</html>

@RequestMapping(value = "/edit/{id}", method = RequestMethod.GET)
    public String getEdit(@PathVariable Integer id, Model model) {
...
}

  @RequestMapping(value = "/edit/{id}", method = RequestMethod.POST)
    public String saveEdit(@ModelAttribute("personAttribute") Person person, 
      @PathVariable Integer id, Model model) {
...
}