微服务项目：尚融宝（10）（后端接口：统一异常处理）

@ApiModelProperty(value = "逻辑删除(1:已删除，0:未删除)")
//@TableField("is_deleted")
@TableLogic
private Boolean deleted;

@Slf4j
@Component //Spring容易自动管理
@RestControllerAdvice //在controller层添加通知。如果使用@ControllerAdvice，则方法上需要添加@ResponseBody
public class UnifiedExceptionHandler {

    /**
     * 未定义异常
     */
    @ExceptionHandler(value = Exception.class) //当controller中抛出Exception，则捕获
    public R handleException(Exception e) {
        log.error(e.getMessage(), e);
        return R.error();
    }
}

@SpringBootApplication
@ComponentScan({"com.atguigu.srb", "com.atguigu.common"})
public class ServiceCoreApplication {

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-jdbc</artifactId>
</dependency>

/**
* 特定异常
*/
@ExceptionHandler(BadSqlGrammarException.class)
public R handleBadSqlGrammarException(BadSqlGrammarException e){
    log.error(e.getMessage(), e);
    return R.setResult(ResponseEnum.BAD_SQL_GRAMMAR_ERROR);
}

@TableField(value = "is_deleted")

@Data
@NoArgsConstructor
public class BusinessException extends RuntimeException {

   //状态码
    private Integer code;

    //错误消息
    private String message;

    /**
     *
     * @param message 错误消息
     */
    public BusinessException(String message) {
        this.message = message;
    }

    /**
     *
     * @param message 错误消息
     * @param code 错误码
     */
    public BusinessException(String message, Integer code) {
        this.message = message;
        this.code = code;
    }

    /**
     *
     * @param message 错误消息
     * @param code 错误码
     * @param cause 原始异常对象
     */
    public BusinessException(String message, Integer code, Throwable cause) {
        super(cause);
        this.message = message;
        this.code = code;
    }

    /**
     *
     * @param resultCodeEnum 接收枚举类型
     */
    public BusinessException(ResponseEnum resultCodeEnum) {
        this.message = resultCodeEnum.getMessage();
        this.code = resultCodeEnum.getCode();
    }

    /**
     *
     * @param resultCodeEnum 接收枚举类型
     * @param cause 原始异常对象
     */
    public BusinessException(ResponseEnum resultCodeEnum, Throwable cause) {
        super(cause);
        this.message = resultCodeEnum.getMessage();
        this.code = resultCodeEnum.getCode();
    }



}

/**
* 自定义异常
*/
@ExceptionHandler(BusinessException.class)
public R handleBusinessException(BusinessException e){
    log.error(e.getMessage(), e);
    return R.error().message(e.getMessage()).code(e.getCode());
}

@ApiOperation("新增积分等级")
@PostMapping("/save")
public R save(
    @ApiParam(value = "积分等级对象", required = true)
    @RequestBody IntegralGrade integralGrade){

    //如果借款额度为空就手动抛出一个自定义的异常！
    if(integralGrade.getBorrowAmount() == null){
        //BORROW_AMOUNT_NULL_ERROR(-201, "借款额度不能为空"),
        throw new BusinessException(ResponseEnum.BORROW_AMOUNT_NULL_ERROR);
    }

    boolean result = integrationService.save(integralGrade);
    if (result) {
        return R.ok().message("保存成功");
    } else {
        return R.error().message("保存失败");
    }
}

public class AssertTests {

	//if else的用法
    @Test
    public void test1() {
        Object o = null;
        if (o == null) {
            throw new IllegalArgumentException("用户不存在.");
        }
    }

	//断言的用法：更为简洁
    @Test
    public void test2() {
        // 另一种写法
        Object o = null;
        Assert.notNull(o, "用户不存在.");
    }
}

@Slf4j
public abstract class Assert {

    /**
     * 断言对象不为空
     * 如果对象obj为空，则抛出异常
     * @param obj 待判断对象
     */
    public static void notNull(Object obj, ResponseEnum responseEnum) {
        if (obj == null) {
            log.info("obj is null...............");
            throw new BusinessException(responseEnum);
        }
    }
}

 Assert.notNull(integralGrade.getBorrowAmount(), ResponseEnum.BORROW_AMOUNT_NULL_ERROR);

/**
     * Controller上一层相关异常
     */
@ExceptionHandler({
    NoHandlerFoundException.class,
    HttpRequestMethodNotSupportedException.class,
    HttpMediaTypeNotSupportedException.class,
    MissingPathVariableException.class,
    MissingServletRequestParameterException.class,
    TypeMismatchException.class,
    HttpMessageNotReadableException.class,
    HttpMessageNotWritableException.class,
    MethodArgumentNotValidException.class,
    HttpMediaTypeNotAcceptableException.class,
    ServletRequestBindingException.class,
    ConversionNotSupportedException.class,
    MissingServletRequestPartException.class,
    AsyncRequestTimeoutException.class
        })
public R handleServletException(Exception e) {
    log.error(e.getMessage(), e);
    //SERVLET_ERROR(-102, "servlet请求异常"),
    return R.error().message(ResponseEnum.SERVLET_ERROR.getMessage()).code(ResponseEnum.SERVLET_ERROR.getCode());
}