SpringMVC之@RequestMapping用法

一、基本介绍
@RequestMapping 注解可以用在类上，也可以用在方法上。

@RestController
@RequestMapping("/home")
public class IndexController {
  @RequestMapping("/")
  String get(){
    return "Hello from get";
  }
  @RequestMapping("/index")
  String index(){
    return "Hello from index";
  }
}


/*

/home       请求，会调用 get()   方法，
/home/index 请求，会调用 index() 方法。

*/

二、一个 @RequestMapping ，匹配多个路径

@RestController
@RequestMapping("/home")
public class IndexController {

@RequestMapping(value={"", "/page", "page*","view/*,**/msg"})
  String indexMultipleMapping(){
    return "Hello from index multiple mapping.";
  }
}


/*

下面的路径都将匹配到 indexMultipleMapping() 方法进行处理：

  - localhost:8080/home
  - localhost:8080/home/
  - localhost:8080/home/page
  - localhost:8080/home/pageabc
  - localhost:8080/home/view/
  - localhost:8080/home/view/view


*/

三、@RequestMapping 中使用 @RequestParam 绑定参数

@RestController	
@RequestMapping("/home")
public class IndexController {
  


/*

匹配：localhost:8090/home/id?_id=5


*/
  @RequestMapping(value = "/id")								
  String getIdByValue(@RequestParam("_id") String personId){
    System.out.println("ID is "+personId);
    return "Get ID from query string of URL with value element";
  }


/*

匹配：localhost:8090/home/personId?personId=5

注意：如果方法参数的 personId 名称 与 请求路径中参数的名称一致，
     则可以省略 @RequestParam 后面小括号的内容
*/

  @RequestMapping(value = "/personId")							
  String getId(@RequestParam String personId){
    System.out.println("ID is "+personId);	
    return "Get ID from query string of URL without value element";	
  }
}


/*

@RequestParam 的 required 属性用法示例

*/
@RestController
@RequestMapping("/home")
public class IndexController {
  @RequestMapping(value = "/name")
  String getName(@RequestParam(value = "person", required = false) String personName){
    return "Required element of request param";
  }
}


/*

@RequestParam 的 defaultValue 属性用法示例

*/
@RestController	
@RequestMapping("/home")
public class IndexController {
  @RequestMapping(value = "/name")
  String getName(@RequestParam(value = "person", defaultValue = "John") String personName ){
    return "Required element of request param";
  }
}

四、@RequestMapping 结合 HTTP 请求方法使用

HTTP 请求方法包括：  GET, PUT, POST, DELETE, and PATCH.

@RestController
@RequestMapping("/home")
public class IndexController {
  @RequestMapping(method = RequestMethod.GET)
  String get(){
    return "Hello from get";									
  }
  @RequestMapping(method = RequestMethod.DELETE)
  String delete(){
    return "Hello from delete";
  }
  @RequestMapping(method = RequestMethod.POST)
  String post(){
    return "Hello from post";
  }
  @RequestMapping(method = RequestMethod.PUT)
  String put(){
    return "Hello from put";
  }
  @RequestMapping(method = RequestMethod.PATCH)
  String patch(){
    return "Hello from patch";
  }
}

/*
请求路径都是 /home，但是根据 http 发送的请求方法的不同，
匹配不同的处理方法。

*/

/*

@RequestMapping 根据请求方法，的简写

*/

@RequestMapping("/home")
public class IndexController {
  @GetMapping("/person")
  public @ResponseBody ResponseEntity<String> getPerson() {
    return new ResponseEntity<String>("Response from GET", HttpStatus.OK);
  }
  @GetMapping("/person/{id}")
  public @ResponseBody ResponseEntity<String> getPersonById(@PathVariable String id){
    return new ResponseEntity<String>("Response from GET with id " +id,HttpStatus.OK);				  }
  @PostMapping("/person")
  public @ResponseBody ResponseEntity<String> postPerson() {
    return new ResponseEntity<String>("Response from POST method", HttpStatus.OK);
  }
  @PutMapping("/person")
  public @ResponseBody ResponseEntity<String> putPerson() {
    return new ResponseEntity<String>("Response from PUT method", HttpStatus.OK);
  }
  @DeleteMapping("/person")
  public @ResponseBody ResponseEntity<String> deletePerson() {
    return new ResponseEntity<String>("Response from DELETE method", HttpStatus.OK); 
  }
  @PatchMapping("/person")
  public @ResponseBody ResponseEntity<String> patchPerson() {
    return new ResponseEntity<String>("Response from PATCH method", HttpStatus.OK);	
  }
}

五、@RequestMapping 缩小匹配范围：限制输入和输出格式

@RestController
@RequestMapping("/home")
public class IndexController {

/*

只匹配消费类型是 application/JSON 的请求
*/
  @RequestMapping(value = "/prod", produces = {"application/JSON"})
  @ResponseBody
  String getProduces(){
    return "Produces attribute";
  }


/*

只匹配输入类型是 application/JSON 或 application/XML 的请求
*/
  @RequestMapping(value = "/cons", consumes = {"application/JSON", "application/XML"})
  String getConsumes(){
    return "Consumes attribute";
  }
}

六、@RequestMapping 缩小匹配范围：限制 Headers 请求头

/*

只匹配 header 中含有：content-type=text/plain 的请求
*/
@RestController	
@RequestMapping("/home")
public class IndexController {
  @RequestMapping(value = "/head", headers = {"content-type=text/plain"})
  String post(){	
    return "Mapping applied along with headers";	
  }								
}


/*

只匹配 header 中含有：content-type=text/plain 或 content-type=text/html 的请求
*/
@RestController
@RequestMapping("/home")
public class IndexController {
  @RequestMapping(value = "/head", headers = {"content-type=text/plain", "content-type=text/html"})		  String post(){
    return "Mapping applied along with headers";
  }								
}

七、@RequestMapping 缩小匹配范围：限制请求参数

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

八、@RequestMapping 动态匹配 URL

@RestController
@RequestMapping("/home")
public class IndexController {
  @RequestMapping(value = "/fetch/{id}", method = RequestMethod.GET)
  String getDynamicUriValue(@PathVariable String id){
    System.out.println("ID is "+id);
    return "Dynamic URI parameter fetched";						
  } 
  @RequestMapping(value = "/fetch/{id:[a-z]+}/{name}", method = RequestMethod.GET)
    String getDynamicUriValueRegex(@PathVariable("name") String name){
    System.out.println("Name is "+name);
    return "Dynamic URI parameter fetched using regex";		
  } 
}

九、@RequestMapping 设定默认匹配的方法

@RestController
@RequestMapping("/home")
public class IndexController {

  /*
这个 @RequestMapping() 什么值也没设定，作为默认处理 /home 请求的方法。
*/
  @RequestMapping()
  String default(){									
    return "This is a default method for the class";
  }
}

转载请注明，
原文出处： http://lixh1986.iteye.com/blog/2429836













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引用：
https://springframework.guru/spring-requestmapping-annotation/