Spring RESTful服务接收跟返回JSON最佳实践(转)
Spring RESTful服务接收和返回JSON最佳实践
个人学习参考所用，勿喷！ ?
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返回JSON
1) 用Maven构建web项目：
构建过程参考limingnihao的blog（写得相当的详细！！！）：使用Eclipse构建Maven的SpringMVC项目
注解@ResponseBody可以将结果（一个包含字符串和JavaBean的Map），转换成JSON。由于Spring是采用对JSON进行了封装的jackson来生成JSON和返回给客户端,所以这里需要添加jackson的相关包。项目的pom.xml配置如下：
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"><modelVersion>4.0.0</modelVersion><groupId>com.watson</groupId><artifactId>rest-spring</artifactId><packaging>war</packaging><version>0.0.1-SNAPSHOT</version><name>rest-spring Maven Webapp</name><url>http://maven.apache.org</url><dependencies><!-- 省略其他配置,具体可以参考附件-->......<dependency><groupId>org.codehaus.jackson</groupId> <artifactId>jackson-mapper-asl</artifactId><version>1.4.2</version></dependency><dependency><groupId>org.codehaus.jackson</groupId> <artifactId>jackson-core-asl</artifactId><version>1.4.2</version></dependency></dependencies></project>
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2) 在web.xml配置Spring的请求处理的Servlet，具体设置：
<?xml version="1.0" encoding="UTF-8"?><web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"version="2.5"><display-name>Spring-Rest</display-name><servlet><servlet-name>rest</servlet-name><servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class><init-param><param-name>contextConfigLocation</param-name><param-value>/WEB-INF/rest-servlet.xml</param-value></init-param><load-on-startup>1</load-on-startup></servlet><servlet-mapping><servlet-name>rest</servlet-name><url-pattern>/</url-pattern></servlet-mapping></web-app>
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3) 在rest-servlet.xml中配置如下：
<beans xmlns="http://www.springframework.org/schema/beans"xmlns:context="http://www.springframework.org/schema/context"xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"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"> <context:component-scan base-package="com.mkyong.common.controller" /><mvc:annotation-driven /></beans>
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?? 为了解决乱码问题，需要添加如下配置，并且这里可以显示的添加MappingJacksonHttpMessageConverter这个转换器。
<bean /></list></property></bean>
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4) 编写自己的服务组件类，使用MVC的annotation风格，使用?@ResponseBody处理返回值。具体代码如下：
@RequestMapping("/jsonfeed")public @ResponseBody Object getJSON(Model model) {List<TournamentContent> tournamentList = new ArrayList<TournamentContent>();tournamentList.add(TournamentContent.generateContent("FIFA", new Date(), "World Cup", "www.fifa.com/worldcup/"));tournamentList.add(TournamentContent.generateContent("FIFA", new Date(), "U-20 World Cup", "www.fifa.com/u20worldcup/"));tournamentList.add(TournamentContent.generateContent("FIFA", new Date(), "U-17 World Cup", "www.fifa.com/u17worldcup/"));tournamentList.add(TournamentContent.generateContent("中超", new Date(), "中超", "www.fifa.com/confederationscup/"));model.addAttribute("items", tournamentList);model.addAttribute("status", 0);return model;}?
?5)将运行项目，在浏览器中输入http://[host]:[port]/[appname]/jsonfeed.json，例如楼主的实例中输入如下：http://localhost:7070/rest-spring/jsonfeed/，得到结果为：
{"status":0,"items":[{"name":"World Cup","id":8,"link":"www.fifa.com/worldcup/","author":"FIFA","publicationDate":1334559460940},{"name":"U-20 World Cup","id":9,"link":"www.fifa.com/u20worldcup/","author":"FIFA","publicationDate":1334559460940},{"name":"U-17 World Cup","id":10,"link":"www.fifa.com/u17worldcup/","author":"FIFA","publicationDate":1334559460940},{"name":"Confederations Cup","id":11,"link":"www.fifa.com/confederationscup/","author":"FIFA","publicationDate":1334559460940}]}?
这里我们也可以利用Spring3MVC中对试图和内容协商的方法来处理返回JSON的情况，下面步骤接上面第2步：
3)?在rest-servlet.xml中对相关进行具体的设置：
<?xml version="1.0" encoding="UTF-8"?><beans xmlns="http://www.springframework.org/schema/beans"xmlns:aop="http://www.springframework.org/schema/aop" xmlns:context="http://www.springframework.org/schema/context"xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:tx="http://www.springframework.org/schema/tx"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd 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 http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd"><!-- 自动搜索@Controller标注的类，包括其下面的子包 --><context:component-scan base-package="com.watson.rest" /><!-- 根据客户端的不同的请求决定不同的view进行响应, 如 /blog/1.json /blog/1.xml --><bean value="true" /><!-- 在没有扩展名时即: "/blog/1" 时的默认展现形式 --><property name="defaultContentType" value="text/html" /><!-- 扩展名至mimeType的映射,即 /blog.json => application/json --><property name="mediaTypes"><map><entry key="html" value="text/html" /><entry key="pdf" value="application/pdf" /><entry key="xsl" value="application/vnd.ms-excel" /><entry key="xml" value="application/xml" /><entry key="json" value="application/json" /></map></property><!-- 用于开启 /blog/123?format=json 的支持 --><property name="favorParameter" value="false" /><property name="viewResolvers"><list><bean /><bean value="org.springframework.web.servlet.view.JstlView" /><property name="prefix" value="/pages" /><property name="suffix" value=".jsp"></property></bean></list></property><property name="defaultViews"><list><!-- for application/json --><bean /><!-- for application/xml --><!-- <bean name="code">//FINAL package com.watson.rest.json;import org.springframework.stereotype.Controller;import org.springframework.ui.Model;import org.springframework.web.bind.annotation.RequestMapping;import com.watson.rest.feeds.TournamentContent;import java.util.ArrayList;import java.util.Date;import java.util.List;@Controllerpublic class FeedController { @RequestMapping("/jsonfeed") public String getJSON(Model model) { List<TournamentContent> tournamentList = new ArrayList<TournamentContent>(); tournamentList.add(TournamentContent.generateContent("FIFA", new Date(), "World Cup", "www.fifa.com/worldcup/")); tournamentList.add(TournamentContent.generateContent("FIFA", new Date(), "U-20 World Cup", "www.fifa.com/u20worldcup/")); tournamentList.add(TournamentContent.generateContent("FIFA", new Date(), "U-17 World Cup", "www.fifa.com/u17worldcup/")); tournamentList.add(TournamentContent.generateContent("FIFA", new Date(), "Confederations Cup", "www.fifa.com/confederationscup/")); model.addAttribute("items", tournamentList); model.addAttribute("status", 0); return "jsontournamenttemplate"; }}?这里的TournamentContent是自定义的POJO类：public class TournamentContent { private static int idCounter = 0; private String author; private Date publicationDate; private String name; private String link; private int id; public static TournamentContent generateContent(String author, Date date, String name, String link) { TournamentContent content = new TournamentContent(); content.author = author; content.publicationDate = date; content.name = name; content.link = link; content.id = idCounter++; return content; }//省略getter、setter}?5)将运行项目，在浏览器中输入http://[host]:[port]/[appname]/jsonfeed.json，例如楼主的实例中输入如下：http://localhost:7070/rest-spring/jsonfeed.json，得到结果为：{"status":0,"items":[{"name":"World Cup","id":8,"link":"www.fifa.com/worldcup/","author":"FIFA","publicationDate":1334559460940},{"name":"U-20 World Cup","id":9,"link":"www.fifa.com/u20worldcup/","author":"FIFA","publicationDate":1334559460940},{"name":"U-17 World Cup","id":10,"link":"www.fifa.com/u17worldcup/","author":"FIFA","publicationDate":1334559460940},{"name":"Confederations Cup","id":11,"link":"www.fifa.com/confederationscup/","author":"FIFA","publicationDate":1334559460940}]}?至此，Spring RESTful服务返回JSON的实践基本完成（因为这里对EXCEPTION的处理还够）。个人认为第一种方式更加适合一般的使用，特别是显示的添加MappingJacksonHttpMessageConverter这个转换器和对乱码的处理。?接收JSON使用 @RequestBody 注解前台只需要向 Controller 提交一段符合格式的 JSON，Spring 会自动将其拼装成 bean。1)在上面的项目中使用第一种方式处理返回JSON的基础上，增加如下方法：@RequestMapping(value="/add",method=RequestMethod.POST)@ResponseBodypublic Object addUser(@RequestBody User user){System.out.println(user.getName() + " " + user.getAge());return new HashMap<String, String>().put("success", "true");}?这里的POJO如下：public class User {private String name;private String age;//getter setter}?2）而在前台，我们可以用 jQuery 来处理 JSON。从这里，我得到了一个 jQuery 的插件，可以将一个表单的数据返回成JSON对象：$.fn.serializeObject = function(){ var o = {}; var a = this.serializeArray(); $.each(a, function(){ if (o[this.name]) { if (!o[this.name].push) { o[this.name] = [o[this.name]]; } o[this.name].push(this.value || ''); } else { o[this.name] = this.value || ''; } }); return o;};??? 以下是使用 jQuery 接收、发送 JSON 的代码：$(document).ready(function(){ jQuery.ajax({ type: 'GET', contentType: 'application/json', url: 'jsonfeed.do', dataType: 'json', success: function(data){ if (data && data.status == "0") { $.each(data.data, function(i, item){ $('#info').append("姓名：" + item.name +"，年龄：" +item.age); }); } }, error: function(){ alert("error") } }); $("#submit").click(function(){ var jsonuserinfo = $.toJSON($('#form').serializeObject()); jQuery.ajax({ type: 'POST', contentType: 'application/json', url: 'add.do', data: jsonuserinfo, dataType: 'json', success: function(data){ alert("新增成功！"); }, error: function(){ alert("error") } }); });});?但是似乎用Spring这套东西真是个麻烦的事情，相对Jersey对RESTful的实现来看，确实有很多不简洁的地方。