Spring MVC 实现RESTful 返回JSON格式数据
在Java后端的日常开发中，系统间调用通过使用json格式数据，本文将向你展示如何将对象转换成json格式并通过Spring MVC框架返回给调用者。
开发工具配置
- Spring 4.2.7.RELEASE
- Jackson 2.6.7
- JDK 1.7
- IntelliJ IDEA 15
- Maven 3.3.9
1、maven依赖
<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>4.0.0modelVersion>
<groupId>com.ricky.codelabgroupId>
<artifactId>springmvcartifactId>
<packaging>warpackaging>
<version>1.0-SNAPSHOTversion>
<name>Spring MVC 4.x Demoname>
<url>http://maven.apache.orgurl>
<properties>
<spring.version>4.2.7.RELEASEspring.version>
<jackson.version>2.6.7jackson.version>
<project.build.sourceEncoding>UTF-8project.build.sourceEncoding>
properties>
<dependencies>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-coreartifactId>
<version>${spring.version}version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-contextartifactId>
<version>${spring.version}version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-context-supportartifactId>
<version>${spring.version}version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-aopartifactId>
<version>${spring.version}version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-beansartifactId>
<version>${spring.version}version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-txartifactId>
<version>${spring.version}version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-jdbcartifactId>
<version>${spring.version}version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-testartifactId>
<version>${spring.version}version>
dependency>
<dependency>
<groupId>org.springframeworkgroupId>
<artifactId>spring-webmvcartifactId>
<version>${spring.version}version>
dependency>
<dependency>
<groupId>com.fasterxml.jackson.coregroupId>
<artifactId>jackson-coreartifactId>
<version>${jackson.version}version>
dependency>
<dependency>
<groupId>com.fasterxml.jackson.coregroupId>
<artifactId>jackson-annotationsartifactId>
<version>${jackson.version}version>
dependency>
<dependency>
<groupId>com.fasterxml.jackson.coregroupId>
<artifactId>jackson-databindartifactId>
<version>${jackson.version}version>
dependency>
<dependency>
<groupId>jstlgroupId>
<artifactId>jstlartifactId>
<version>1.2version>
dependency>
<dependency>
<groupId>taglibsgroupId>
<artifactId>standardartifactId>
<version>1.1.2version>
dependency>
<dependency>
<groupId>javax.servletgroupId>
<artifactId>javax.servlet-apiartifactId>
<version>3.1.0version>
<scope>compilescope>
dependency>
<dependency>
<groupId>junitgroupId>
<artifactId>junitartifactId>
<version>4.12version>
<scope>testscope>
dependency>
dependencies>
<profiles>
<profile>
<id>betaid>
<build>
<resources>
<resource>
<directory>src/main/resourcesdirectory>
resource>
<resource>
<directory>src/main/resources_betadirectory>
resource>
resources>
build>
<activation>
<activeByDefault>trueactiveByDefault>
activation>
profile>
<profile>
<id>onlineid>
<build>
<resources>
<resource>
<directory>src/main/resourcesdirectory>
resource>
<resource>
<directory>src/main/resources_onlinedirectory>
resource>
resources>
build>
profile>
profiles>
<build>
<finalName>springmvcfinalName>
build>
project>2、Spring配置文件
applicationContext.xml
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:jee="http://www.springframework.org/schema/jee" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:task="http://www.springframework.org/schema/task" xmlns:util="http://www.springframework.org/schema/util" xmlns:jaxws="http://cxf.apache.org/jaxws"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/util
http://www.springframework.org/schema/util/spring-util.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd"
default-lazy-init="false">
<util:properties id="db" location="classpath:mysql.properties"/>
<context:component-scan base-package="com.ricky.codelab" />
<context:annotation-config />
<import resource="spring-mvc.xml"/>
beans>spring-mvc.xml
<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.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.1.xsd
http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.1.xsd">
<context:component-scan base-package="com.ricky.codelab.springmvc.controller">context:component-scan>
<mvc:annotation-driven/>
<bean id="viewResolver" class="org.springframework.web.servlet.view.UrlBasedViewResolver">
<property name="viewClass"
value="org.springframework.web.servlet.view.JstlView" />
<property name="prefix" value="/WEB-INF/pages/" />
<property name="suffix" value=".jsp" />
bean>
beans>3、web.xml
<web-app>
<display-name>Spring MVC 4.2 Demodisplay-name>
<context-param>
<param-name>contextConfigLocationparam-name>
<param-value>
classpath*:/applicationContext*.xml;
param-value>
context-param>
<filter>
<filter-name>characterEncodingFilterfilter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilterfilter-class>
<init-param>
<param-name>encodingparam-name>
<param-value>UTF-8param-value>
init-param>
<init-param>
<param-name>forceEncodingparam-name>
<param-value>trueparam-value>
init-param>
filter>
<filter-mapping>
<filter-name>characterEncodingFilterfilter-name>
<url-pattern>/*url-pattern>
filter-mapping>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListenerlistener-class>
listener>
<servlet>
<servlet-name>SpringMVCservlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServletservlet-class>
<init-param>
<param-name>contextConfigLocationparam-name>
<param-value>classpath*:spring-mvc.xmlparam-value>
init-param>
<load-on-startup>1load-on-startup>
servlet>
<servlet-mapping>
<servlet-name>SpringMVCservlet-name>
<url-pattern>/url-pattern>
servlet-mapping>
<welcome-file-list>
<welcome-file>index.jspwelcome-file>
welcome-file-list>
web-app>4、Model
package com.ricky.codelab.springmvc.domain;
/**
* ${DESCRIPTION}
*
* @author Ricky Fung
* @create 2016-07-12 16:54
*/
public class User {
private String username;
private String password;
private String email;
private int age;
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
}5、Controller
在需要返回json格式数据的Controller method上添加@ResponseBody注解，如下：
package com.ricky.codelab.springmvc.controller;
import com.ricky.codelab.springmvc.domain.User;
import com.ricky.codelab.springmvc.service.IUserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.*;
/**
* Spring MVC RESTful JSON
*
* @author Ricky Fung
* @create 2016-07-13 11:41
*/
@Controller
@RequestMapping("/user")
public class RESTfulJSONController {
@Autowired
private IUserService userService;
/**Spring MVC RESTful JSON**/
@RequestMapping(value = "/view/{username}", method = RequestMethod.GET)
@ResponseBody
public User view(@PathVariable String username){
System.out.println("view username:"+username);
return userService.findUserByName(username);
}
@RequestMapping(value = "/query", method = RequestMethod.GET)
@ResponseBody
public User query(@RequestParam(value="username", required=true) String username){
System.out.println("view username:"+username);
return userService.findUserByName(username);
}
}
Spring MVC框架会自动帮我们将Object 转换为JSON string。
6、验证结果
打开浏览器，访问
http://localhost:8080/user/view/ricky 或者
http://localhost:8080/user/query?username=ricky
返回结果：
{
username: “ricky “,
password: “123”,
email: “ricky @163.com”,
age: 27
}