SpringBoot使用@Validated处理校验的方法步骤

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-validation</artifactId>
</dependency>

@RestController
@RequestMapping("/test")
@Validated
public class TestController {
    @PostMapping()
    public R test(@Valid @RequestBody TestDTO dto){
        return R.ok("响应成功");
    }
}

/**
	 *处理参数校验异常
	 * @param e
	 * @return
	 */
	@ExceptionHandler
	public R handlerException(MethodArgumentNotValidException e) {
		e.printStackTrace();
		BindingResult bindingResult = e.getBindingResult();
		return R.fail(bindingResult.getFieldErrors().get(0).getDefaultMessage());
	}

import lombok.Data;
import javax.validation.constraints.NotBlank;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Size;
@Data
public class TestDTO {
    @NotBlank(message = "a参数不能为空")
    private String a;
    @NotNull(message = "b参数不能为null")
    private String b;
    @Max(value = 10,message = "请输入正确的范围")
    private Integer c;
}