SpringMVC学习 -- REST

REST：表现层状态转化。

• REST 是目前最流行的一种互联网软件架构。他结构清晰。符合标准、易于理解、扩展方便 , 所以正得到越来越多网站的采用。
• 状态转化：浏览器 form 表单只支持 GET 和 POST 请求 , 而 DELETE 、PUT 等 method 名不支持 , Spring3.0 添加 HiddenHttpMethodFilter 过滤器 , 可以将这些请求转换为标准的 http 方法 , 使得支持 GET , POST , PUT 与 DELETE 请求。

 web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
         version="3.1">

    <!--
        配置 org.springframework.web.filter.HiddenHttpMethodFilter 拦截器,
        可以把 POST 请求转化为 PUT , DELETE 请求。
     -->
    <filter>
        <filter-name>hiddenHttpMethodFilter</filter-name>
        <filter-class>org.springframework.web.filter.HiddenHttpMethodFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>hiddenHttpMethodFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>/WEB-INF/applicationContext.xml</param-value>
    </context-param>
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
    <servlet>
        <servlet-name>dispatcher</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>dispatcher</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>
</web-app>

dispatcher-servlet.xml

<?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"
       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.xsd">
    <!-- 扫描自定义包 -->
    <context:component-scan base-package="com.itdoc.springmvc"/>

    <!-- 配置试图解析器: 把 Controller 返回值解析成实际的物理视图 -->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/views/"/>
        <property name="suffix" value=".jsp"/>
    </bean>
</beans>

TestRest.java

package com.itdoc.springmvc;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

/**
 * @BLOG http://www.cnblogs.com/goodcheap
 * @DESCRIBE REST 风格
 * @AUTHOR WángChéngDá
 * @DATE 2017-03-09 8:58
 */
@Controller
public class TestRest {

    private final static String SUCCESS = "success";


    /**
     * REST 风格的 URL
     * 1.配置 HiddenHttpMethodFilter。
     * 2.发送 POST 请求。发送 POST 请求同时必须携带一个 name="_method" 的隐藏域,
     * 值为 DELETE 或 PUT, 不区分大小写。
     * 3.通过 HiddenHttpMethodFilter 将 POST 请求转换为想要转换的 DELETE 或 PUT 请求。
     * 4.通过 @PathVariable 注解接收请求中占位符 {xxx} 中的值到方法的入参中。
     */
    @RequestMapping(value = "/testDelete/{id}", method = RequestMethod.DELETE)
    public String testDelete(@PathVariable("id") Integer id) {
        System.out.println("I am TestRest's testDelete method... \t id: " + id);
        return SUCCESS;
    }

    @RequestMapping(value = "/testPut/{id}", method = RequestMethod.PUT)
    public String testPut(@PathVariable("id") Integer id) {
        System.out.println("I am TestRest's testPut method... \t id: " + id);
        return SUCCESS;
    }

    @RequestMapping(value = "/testPost", method = RequestMethod.POST)
    public String testPost() {
        System.out.println("I am TestRest's testPost method...");
        return SUCCESS;
    }

    @RequestMapping("/testGet")
    public String testGet() {
        System.out.println("I am TestRest's testGet method...");
        return  SUCCESS;
    }
}