SpringBoot 通过注解给属性添加校验并返回统一结果

1、添加HttpStatus的依赖包

    org.apache.httpcomponents
    httpcore
    4.4.15
    compile

2、添加校验依赖包

    org.springframework.boot
    spring-boot-starter-validation
    2.7.2

3、定义一个统一的返回结果类R

package com.xu.common.utils;

import org.apache.http.HttpStatus;

import java.util.HashMap;
import java.util.Map;

/**
 * 返回数据
 */
public class R extends HashMap {
   private static final long serialVersionUID = 1L;
   
   public R() {
      put("code", 0);
      put("msg", "success");
   }
   
   public static R error() {
      return error(HttpStatus.SC_INTERNAL_SERVER_ERROR, "未知异常，请联系管理员");
   }
   
   public static R error(String msg) {
      return error(HttpStatus.SC_INTERNAL_SERVER_ERROR, msg);
   }
   
   public static R error(int code, String msg) {
      R r = new R();
      r.put("code", code);
      r.put("msg", msg);
      return r;
   }

   public static R ok(String msg) {
      R r = new R();
      r.put("msg", msg);
      return r;
   }
   
   public static R ok(Map map) {
      R r = new R();
      r.putAll(map);
      return r;
   }
   
   public static R ok() {
      return new R();
   }

   public R put(String key, Object value) {
      super.put(key, value);
      return this;
   }
}

4、枚举异常状态码

public enum ErrorCodeEnume {

    UNKNOW_EXCEPTION(10000,"系统未知异常"),
    VAILD_EXCEPTION(10001,"参数格式校验失败");

    private int code;
    private String msg;
    BizCodeEnume(int code,String msg){
        this.code = code;
        this.msg = msg;
    }

    public int getCode() {
        return code;
    }

    public String getMsg() {
        return msg;
    }
}

5、在需要校验的实体类的属性上添加注解

@NotBlank(message = "用户名不能为空")
private String name;

6.1、在controller中添加 @valid注解与BindingResult

@RequestMapping("/save")
public R save(@Valid @RequestBody User user, BindingResult result) {
    if (result.hasErrors()) {
        Map map = new HashMap<>();
        result.getFieldErrors().forEach((item)->{
            String message = item.getDefaultMessage();
            String field = item.getField();
            map.put(field,message);
        });
        return R.error(ErrorCodeEnume.VAILD_EXCEPTION.getCode(), ErrorCodeEnume.VAILD_EXCEPTION.getMsg()).put("data",map);
    }
    else
    {
        UserService.save(user);
    }
    return R.ok();
}

6.2或者利用RestControllerAdvice注解将异常统一抛出（这个注解利用AOP原理）

import com.xu.common.utils.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.validation.BindingResult;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.bind.annotation.*;

import java.util.HashMap;
import java.util.Map;

@Slf4j
@RestControllerAdvice(basePackages = "需要检测异常的包名，一般为controller包")
public class ExceptionController {
    @ExceptionHandler(value = MethodArgumentNotValidException.class)
    public R handleVaildException(MethodArgumentNotValidException e){
        Map map = new HashMap<>();
        BindingResult result = e.getBindingResult();
        result.getFieldErrors().forEach((item)->{
            String message = item.getDefaultMessage();
            String field = item.getField();
            map.put(field,message);
        });
        log.error("数据校验出现问题{}",map);
       return R.error(ErrorCodeEnume.VAILD_EXCEPTION.getCode(), ErrorCodeEnume.VAILD_EXCEPTION.getMsg()).put("data",map);
    }
}

@ExceptionHandler(value = Throwable.class)
public R handleException(Throwable throwable)
{
    return R.error(ErrorCodeEnume.UNKNOW_EXCEPTION.getCode(), ErrorCodeEnume.UNKNOW_EXCEPTION.getMsg());
}

7、通过postman测试返回结果

  "msg": "提交的数据不合法",

    "code": 400,

    "data": {

        "name": "用户名不能为空"

    }