spring_restful_json_jdbc

浏览数：24 / 时间：2015年06月12日

来源：http://blog.csdn.net/qduningning/article/details/27712137

使用Spring MVC +JDBC 实现输出Json数据和视图两种形式最后面有源码

从web.xml开始配置：

声明定义两个Servlet分别是输出视图和json

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<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>/rest/*</url-pattern>
</servlet-mapping>
<servlet>
<servlet-name>json</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/json-servlet.xml</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>json</servlet-name>
<url-pattern>/json/*</url-pattern>
</servlet-mapping>

其他配置略过
首先是第一个Servlet – rest，指定的配置文件rest-servlet.xml(默认也是,,,)

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<?xml version="1.0" encoding="UTF-8"?>
<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.znn.rest.controller">
</context:component-scan>
<!-- 简写形式会自动注册DefaultAnnotationHandlerMapping与AnnotationMethodHandlerAdapter两个bean,是spring
MVC为@Controllers分发请求所必须的。 -->
<mvc:annotation-driven />
<bean
class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/jsp/" />
<property name="suffix" value=".jsp" />
</bean>
</beans>

在包com.znn.rest.controller下创建一个Controller：UserController.java
用注解@Controller进行声明这是一个Controller，Spring会自动扫描到

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package com.znn.rest.controller;
import java.lang.reflect.Method;
import java.util.List;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestHeader;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import com.znn.dao.UserDao;
import com.znn.vo.User;
/**
* RestFul 返回视图
*
* @author RANDY.ZHANG
* 2014-5-7
*/
@Controller
public class UserController {
ApplicationContext applicationContext = new ClassPathXmlApplicationContext("beans.xml");
UserDao dao = (UserDao) applicationContext.getBean("userDao");
@RequestMapping("/hi")
public String helloWorld(Model model) {
model.addAttribute("msg", "Hello HelloWorld");
return "hello";
// return "redirect:hello.jsp";
}
@RequestMapping("/user/{id:\\d+}")
public String getUser(Model model,@PathVariable("id") int userid) {
User user;
user = dao.queryAUser(userid);
if (user == null) {
model.addAttribute("tip", "用户不存在！");
}else {
model.addAttribute("tip", user.toString());
}
return "user";
}
@RequestMapping(value = "/user/*",method=RequestMethod.GET)
public String getAllUser(Model model) {
List<User> list = dao.query();
String tipString = "";
for (int i = 0; i < list.size(); i++) {
tipString += list.get(i).toString()+" ";
}
model.addAttribute("tip",tipString);
return "user";
}
@RequestMapping(value = "/user",method=RequestMethod.GET)
public String getAUser(Model model,
@RequestParam(value="id",required=false,defaultValue="1") int userid,
@RequestHeader("user-agent") String agent) {
User user;
user = dao.queryAUser(userid);
if (user == null) {
model.addAttribute("tip", "用户不存在！");
}else {
model.addAttribute("tip", user.toString());
}
System.out.println(agent);
return "user";
}
}

使用InternalResourceViewResolver进行视图适配，方法返回的字符串会自动添加上前后缀，另外还支持redirect:和forward：两种特殊配置，只是注意下要路径。
关于MVC的注解以及RequestMapping的配置用法到:http://docs.spring.io/spring-framework/docs/current/spring-framework-reference/html/mvc.html#mvc-introduction，里面讲的挺详细。

第二种输出JSON：
从Spring 3.1开始支持@ResponseBody来直接将数据返回到HTTP响应体重，不在需要ModalView或者其他进行渲染。Spring提供了一些HttpMessageConverter来对数据进行转换，比如StringHttpMessageConverter，FormHttpMessageConverter，MappingJackson2HttpMessageConverter ，其他见这里，这里用到了StringHttpMessageConverter用来进行编码转换，MappingJackson2HttpMessageConverter 用来将数据转为Json形式。
json-servlet.xml

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<?xml version="1.0" encoding="UTF-8"?>
<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.znn.json.controller">
</context:component-scan>
<bean
class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping" />
<bean
class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">
<property name="messageConverters">
<list>
<bean
class="org.springframework.http.converter.StringHttpMessageConverter">
<property name="supportedMediaTypes">
<list>
<value>text/html; charset=UTF-8</value>
</list>
</property>
</bean>
<bean
class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
<property name="supportedMediaTypes">
<list>
<value>text/html; charset=UTF-8</value>
</list>
</property>
</bean>
</list>
</property>
</bean>
</beans>

从3.1开始推荐使用RequestMappingHandlerMapping和RequestMappingHandlerAdapter来代替DefaultAnnotationHandlerMapping和AnnotationMethodHandlerAdapter。不过不换也木事。。。。
在com.znn.json.controller下新建一个Controller
UserJson.java

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package com.znn.json.controller;
import java.util.List;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import com.znn.dao.UserDao;
import com.znn.vo.User;
/**
* 返回@ResponseBody需要配置HttpMessageConverters
*
* @author RANDY.ZHANG
* 2014-5-7
*/
@Controller
public class UserJson {
ApplicationContext applicationContext = new ClassPathXmlApplicationContext("beans.xml");
UserDao dao = (UserDao) applicationContext.getBean("userDao");
@RequestMapping("/hi")
public @ResponseBody String helloWorld(Model model) {
// model.addAttribute("msg", "Hello HelloWorld");
return "hello world";
// return "redirect:hello.jsp";
}
@RequestMapping("/user/{id:\\d+}")
public @ResponseBody User getUser(Model model,@PathVariable int id) {
User user;
user = dao.queryAUser(id);
if (user == null) {
model.addAttribute("tip", "用户不存在！");
}else {
model.addAttribute("tip", user.toString());
}
return user;
}
@RequestMapping(value = {"/user/*","/user"},method=RequestMethod.GET)//,produces="application/json" 406
public @ResponseBody List<User> getAllUser(Model model) {
List<User> list = dao.query();
String tipString = "";
for (int i = 0; i < list.size(); i++) {
tipString += list.get(i).toString()+" ";
}
model.addAttribute("tip",tipString);
return list;
}
@RequestMapping(value = "/user/aaa",method=RequestMethod.GET)
public @ResponseBody List<User> getTest(Model model,HttpServletResponse response, HttpServletRequest request) {
List<User> list = dao.query();
String tipString = "";
for (int i = 0; i < list.size(); i++) {
tipString += list.get(i).toString()+" ";
}
model.addAttribute("tip",tipString);
return list;
}
}