Spring 处理请求和响应相关的注解

@Controller

默认返回 templates 目录下的 string.html 页面内容。
在方法中加上 @ResponseBody 注解，可以返回JSON、XML或自定义mediaType的内容

@RestController

直接返回内容，会自动将对象实体转换为JSON格式，视图解析器 InternalResourceViewResolver 不起作用。
@RestController = @Controller + @ResponseBody

@RequestBody

接收请求体中的 JSON 数据，通过实体类的setter方法赋值给属性。
json 的 "" => 实体 String 为 ""
json 的 "" => 实体 Integer、Double 为 null
json 的 null => 实体为 null
@RequestBody 可以与 @RequestParam() 同时使用，@RequestBody 最多只能有一个，@RequestParam() 可以有多个。

以 String 接收数据

@RequestMapping("/index")
public String indexMapping(@RequestBody String jsonStr) {return jsonStr;
}

以对象实体接收数据

// {"name":"hanmeimei","age":12}
@RequestMapping("/index")
public String indexMapping(@RequestBody User user) {return user.toString();
}

以复杂的对象实体接收数据

public class Team {private Integer id;private String name;private List<String> honors;private List<User> members;
}// {
//     "id": 1,
//     "name": "good",
//     "honors": ["very good", "very fast"],
//     "members": [{"name":"hanmeimei","age":12},
//                 {"name":"lilei","age":13}],
// }
@RequestMapping("/index")
public String indexMapping(@RequestBody Team team) {return team.toString();
}

@ResponseBody

将对象实体转换为JSON、XML或自定义mediaType的内容，并在 HTTP response body 中返回

@RequestMapping

将请求映射到控制器上，可以在控制器类和/或方法上使用。

处理单个请求

@RequestMapping("/home")
public class IndexController {@RequestMapping("/index")String indexMapping() {return "Hello from index mapping.";}
}

处理多个请求

@RequestMapping("/home")
public class IndexController {@RequestMapping(value = {"/","/index","/index/*.html","/index/**/*.html"})String indexMultipleMapping() {return "Hello from index multiple mapping.";}
}

处理请求类型

默认是 HTTP GET 类型的。

@RequestMapping(value = "/home", method = RequestMethod.GET)
String get() {}@RequestMapping(value = "/home", method = RequestMethod.DELETE)
String delete() {}@RequestMapping(value = "/home", method = RequestMethod.POST)
String post() {}@RequestMapping(value = "/home", method = RequestMethod.PUT)
String put() {}@RequestMapping(value = "/home", method = RequestMethod.PATCH)
String patch() {}

处理请求类型快捷方式

@GetMapping(value = "/home")
String get() {}@DeleteMapping(value = "/home")
String delete() {}@PostMapping(value = "/home")
String post() {}@PutMapping(value = "/home")
String put() {}@PatchMapping(value = "/home")
String patch() {}

处理生产和消费对象

public class IndexController {// 生产 application/JSON 响应@RequestMapping(value = "/prod", produces = {"application/JSON"})@ResponseBodyString getProduces() {return "Produces attribute";}// 消费 application/JSON & application/XML 请求@RequestMapping(value = "/cons", consumes = {"application/JSON","application/XML"})@ResponseBodyString getConsumes() {return "Consumes attribute";}
}

处理消息头

public class IndexController {// 处理 Content-Type=application/json 的请求@RequestMapping(value = "/head", headers = {"Content-Type=application/json"})String head() {return "Mapping applied along with headers";}
}

public class IndexController {@RequestMapping(value = "/head", headers = {"Content-Type=text/plain","Content-Type=application/json"})String head() {return "Mapping applied along with headers";}
}

处理请求参数

public class IndexController {@RequestMapping(value = "/fetch", params = {"personId=10"})String getParams10(@RequestParam("personId") String id) {return "Fetched parameter using params attribute = " + id;}@RequestMapping(value = "/fetch", params = {"personId=20"})String getParams20(@RequestParam("personId") String id) {return "Fetched parameter using params attribute = " + id;}
}

处理动态 URI

public class IndexController {@RequestMapping(value = "/fetch/{id}")String getDynamicUriValue(@PathVariable String id) {return "Dynamic URI parameter fetched";}@RequestMapping(value = "/fetch/{id:\d+}/{name}")String getDynamicUriValueRegex(@PathVariable("id") int id, @PathVariable("name") String name) {return "Dynamic URI parameter fetched using regex";}
}

默认的处理方法

public class IndexController {@RequestMapping()String default () {return "This is a default method for the class";}
}

参考 RequestBody的使用