SpringMVC-REST风格

• REST(Respresentational State Transfer),表现形式状态转换

  • 传统风格资源描述：
    • http://localhost/user/getById?id=1
    • http://localhost/user/saveUser
  • REST风格描述形式
    • http://ocalhost/user/1
    • http://locahost/user

• 优点：

  • 隐藏资源的访问行为，无法通过地址得知资源是何种操作
  • 书写简化

• 按照REST风格访问资源时使用行为动作区分对资源进行了何种操作

  • GET(查询)
  • POST(新增/保存)
  • DELETE(删除)
  • PUT(修改/更新)

• 上述行为是约定方式，约定不是规范，可以打破，所以是REST风格，而不是规范

• 描述模块的名称通常使用复数，也就是加s的格式描述，表示此类资源，而非单个资源，例如：users,books,accounts

• 根据REST风格对资源进行访问成为RESTful

@Controller
public class UserController {

    //添加请求方法，value可以省略
    @RequestMapping(value = "/users", method = RequestMethod.POST)
    @ResponseBody
    public String save(User user) {
        System.out.println("user save ... " + user);
        return "{'module':'user save'}";
    }

    @RequestMapping(value = "/users/{id}", method = RequestMethod.DELETE)
    @ResponseBody
//    @PathVariable表示变量在路径上,同时把路径名写成/find/{id}
    public String delete(@PathVariable Integer id) {
        System.out.println("user delete ... " + id);
        return "{'module':'user delete'}";
    }

    @RequestMapping(value = "/users", method = RequestMethod.PUT)
    @ResponseBody
    public String update(User user) {
        System.out.println("user update ... " + user);
        return "{'module':'user update'}";
    }

//    @RequestMapping(value = "/users/{id}", method = RequestMethod.GET)
//    @ResponseBody
//    public String find(@PathVariable Integer id) {
//        System.out.println("user save ... " + id);
//        return "{'module':'user find'}";
//    }

    @RequestMapping(value = "/users/{id}", method = RequestMethod.GET)
    @ResponseBody
    public String getById(@PathVariable Integer id) {
        System.out.println("user get by id: ... " + id);
        return "{'module':'getById'}";
    }

    @RequestMapping(value = "/users", method = RequestMethod.GET)
    @ResponseBody
    public String getAll() {
        System.out.println("user get all ... ");
        return "{'module':'get all'}";
    }
}

@RequestBody @RequestParam @PathVariable

• 区别：
  • @RequestParam用于接收url地址传参或表单传参
  • @RequestBody用于接收json数据
  • @PathVariable用于接收路劲参数，使用{参数名称}描述路劲参数
• 应用：
  • 后期开发中，发送请求参数超过1个时，以json格式为主，@RequestBody应用较广
  • 如果发送非json数据格式，选用@RequestParam接收请求参数
  • 采用RESTful进行开发，当参数数量较少时，例如一个，可以采用@PathVariable接收请求路径变量，通常用于传递id值

//@Controller
//@ResponseBody
//上面两个注解可以简化成@RestController注解
@RestController
@RequestMapping("/books")
public class BookController {

    //添加请求方法，value可以省略
//    @RequestMapping(method = RequestMethod.POST)
    //上面的注解可以简化成下面的注解
    @PostMapping
    public String save(User user) {
        System.out.println("user save ... " + user);
        return "{'module':'user save'}";
    }

    //    @RequestMapping(value = "/{id}", method = RequestMethod.DELETE)
    @DeleteMapping("/{id}")
    public String delete(@PathVariable Integer id) {
        System.out.println("user delete ... " + id);
        return "{'module':'user delete'}";
    }

    //    @RequestMapping(method = RequestMethod.PUT)
    @PutMapping
    public String update(User user) {
        System.out.println("user update ... " + user);
        return "{'module':'user update'}";
    }


    //    @RequestMapping(value = "/{id}", method = RequestMethod.GET)
    @GetMapping("/{id}")
    public String getById(@PathVariable Integer id) {
        System.out.println("user get by id: ... " + id);
        return "{'module':'getById'}";
    }

    //    @RequestMapping(method = RequestMethod.GET)
    @GetMapping
    public String getAll() {
        System.out.println("user get all ... ");
        return "{'module':'get all'}";
    }
}

• IDEA中多个光标：Shift+Alt+鼠标左键

@RestController
@RequestMapping("/books")
public class BookController {

    @PostMapping
    public String save(@RequestBody Book book) {
        System.out.println("book save ==>" + book);
        return "{'module':'book save ... success'}";
    }

    @GetMapping
    public List getAll() {
        Book book1 = new Book();
        book1.setType("计算机");
        book1.setName("SpringMVC入门教程");
        book1.setDescription("小试牛刀");

        Book book2 = new Book();
        book2.setType("计算机");
        book2.setName("SpringMVC实战教程");
        book2.setDescription("一代宗师");

        List bookList = new ArrayList<>();
        bookList.add(book1);
        bookList.add(book2);
        return bookList;
    }

}

@Configuration
public class SpringMvcSupport extends WebMvcConfigurationSupport {

    @Override
    //添加资源过滤器
    protected void addResourceHandlers(ResourceHandlerRegistry registry) {
        //当访问/pages/???的时候，走/pages目录下的内容
        registry.addResourceHandler("/pages/**").addResourceLocations("/pages/");
        registry.addResourceHandler("/js/**").addResourceLocations("/js/");
        registry.addResourceHandler("/css/**").addResourceLocations("/css/");
        registry.addResourceHandler("/plugins/**").addResourceLocations("/plugins/");
    }
}

@Configuration
@ComponentScan({"com.itheima.controller", "com.itheima.config"})
@EnableWebMvc
public class SpringMvcConfig {
}

//添加
saveBook() {
    axios.post("/books", this.formData).then((res) => {
    });
},

//主页列表查询
getAll() {
    axios.get("/books").then((res) => {
        this.dataList = res.data;
    });
},