全局异常

创建异常处理类

@RestControllerAdvice //复合注解,标注为异常处理类,+ResponseBody
public class GlobalExceptionHandler {

    @ExceptionHandler(Exception.class)
    public R error(Exception e){
        e.printStackTrace();
        return R.error().message("执行了Exception全局异常");
     }
}

特殊异常

与全局异常类似,指定异常类为特殊的异常类

@RestControllerAdvice
public class GlobalExceptionHandler {

    //特殊异常
    @ExceptionHandler(ArithmeticException.class)
    public R error(ArithmeticException e){
        e.printStackTrace();
        return R.error().message("执行了ArithmeticException特殊异常");
    }
}

自定义异常

创建自定义异常类,继承RuntimeException

@Data
@AllArgsConstructor
@NoArgsConstructor
public class MyException extends RuntimeException {
    @ApiModelProperty(value = "状态码")
    private Integer code;
    @ApiModelProperty(value = "错误消息")
    private String msg;
}

在异常处理类中添加异常处理

@RestControllerAdvice
public class GlobalExceptionHandler {

    //自定义异常
    @ExceptionHandler(MyException.class)
    public R error(MyException e){
        e.printStackTrace();
        return R.error().code(e.getCode()).message(e.getMsg());
    }
}

使用自定义异常

   try {
            int i = 10/0;
        } catch (Exception e) {
             throw new MyException(20003,"自定义MyException错误异常");
        }

R对象为预封装的返回统一结果值

统一返回对象

@Data
public class R {
    @ApiModelProperty(value = "是否成功")
    private Boolean success;
    @ApiModelProperty(value = "返回码")
    private Integer code;

    @ApiModelProperty(value = "返回消息")
    private String message;

    @ApiModelProperty(value = "返回数据")
    private Map<String, Object> data = new HashMap<String, Object>();

    private R(){}

    public static R ok(){
        R r = new R();
        r.setSuccess(true);
        r.setCode(ResultCode.SUCCESS);
        r.setMessage("成功");
        return r;
    }

    public static R error(){
        R r = new R();
        r.setSuccess(false);
        r.setCode(ResultCode.ERROR);
        r.setMessage("失败");
        return r;
    }

    public R success(Boolean success){
        this.setSuccess(success);
        return this;
    }

    public R message(String message){
        this.setMessage(message);
        return this;
    }

    public R code(Integer code){
        this.setCode(code);
        return this;
    }

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

    public R data(Map<String, Object> map){
        this.setData(map);
        return this;
    }
}

封装返回状态码与消息,常量

public interface   ResultCode {

    public static Integer SUCCESS = 200;

    public static Integer ERROR = 4000;


}