Spring 处理 HTTP 请求参数注解的操作方法

/**
 * Find a registered {@link HandlerMethodArgumentResolver} that supports
 * the given method parameter.
 */
@Nullable
private HandlerMethodArgumentResolver getArgumentResolver(MethodParameter parameter) {
    HandlerMethodArgumentResolver result = this.argumentResolverCache.get(parameter);
    if (result == null) {
        for (HandlerMethodArgumentResolver resolver : this.argumentResolvers) {
            if (resolver.supportsParameter(parameter)) {
                result = resolver;
                this.argumentResolverCache.put(parameter, result);
                break;
            }
        }
    }
    return result;
}

// 1 @RequestParam 
// 1.1 指定属性名
@GetMapping("/test")
public Result test(@RequestParam("param") String param);
// 1.2 指定非必传，默认是必传
@GetMapping("/test")
public Result test(@RequestParam(value = "param", required = false) String param);
// 2 @RequestBody
@PostMapping("/test")
public Result test(@RequestBody Map<String, Object> params);
// 3 @RequestPart
@PostMapping("/test")
public Result test(@RequestParam("file") MultipartFile file, @RequestPart("params") Map<String, Object> params);
// 4 @RequestHeader
@GetMapping("/test")
public Result test(@RequestHeader("param") String param);
// 5 @RequestAttribute
@GetMapping("/test")
public Result test(@RequestAttribute("param") String param);
// 6 @PathVariable
@GetMapping("/test/{param}")
public Result test(@PathVariable("param") String param);
// 7 @CookieValue
@GetMapping("/test")
public Result test(@CookieValue("param") String param);
// 8 @SessionAttribute
@GetMapping("/test")
public Result test(@SessionAttribute("param") String param);