Springboot中-全局异常处理类用法示例

　　使用springboot搭建web项目的时候，一般都会添加一个全局异常类，用来统一处理各种自定义异常信息，

和其他非自定义的异常信息，以便于统一返回错误信息。下面就是简单的示例代码，

自定义异常信息.

public class MyException extends RuntimeException{

    private String errorCode = ResultEnum.OTHER_EXCEPTION.getCode();

    private String errorMessage ;

    public String getErrorCode() {
        return errorCode;
    }

    public void setErrorCode(String errorCode) {
        this.errorCode = errorCode;
    }

    public String getErrorMessage() {
        return errorMessage;
    }

    public void setErrorMessage(String errorMessage) {
        this.errorMessage = errorMessage;
    }

    public MyException() {
        super();
    }

    public MyException(String errorCode, String... errorParam) {
        super();
        setErrorMessage(errorCode, errorParam);
    }

    private void setErrorMessage(String code, String... param) {
        this.errorCode = code;
        if (param == null) {
            this.errorMessage = "系统异常";
        } else if (param.length == 1) {
            this.errorMessage = param[0];
        } else if (param.length > 1) {
            this.errorMessage = "系统异常";
        }
    }
}

全局异常信息处理类.

@Slf4j
@RestControllerAdvice
public class GlobalExceptionHandler {

    /*
     * 处理自定义异常
     */
    @ExceptionHandler(value = MyException.class)
    public @ResponseBody JsonResult exceptionHandler (MyException myException) {
        log.info("exceptionHandler--->{}", myException);
        JsonResult jsonResult = new JsonResult();
        jsonResult.setErrorCode(myException.getErrorCode());
        jsonResult.setErrorMessage(myException.getErrorMessage());
        return jsonResult;
    }

    /*
     * 处理参数校验异常-1
     * */
    @ExceptionHandler(value = MethodArgumentNotValidException.class)
    public @ResponseBody JsonResult methodArgumentNotValidExceptionHandler (MethodArgumentNotValidException mANValidException) {
        log.info("参数校验异常1!");
        JsonResult jsonResult = new JsonResult();
        jsonResult.setErrorCode(ResultEnum.PARAMS_ERROE.getCode());
        // 获取所有的校验错误信息
        List<ObjectError> allErrors = mANValidException.getBindingResult().getAllErrors();
        StringBuilder sb = new StringBuilder();
        // 处理错误的校验信息
        if (allErrors != null && allErrors.size() > 1) {
            allErrors.forEach(item->sb.append(item.getDefaultMessage()).append("#"));
        } else {
            allErrors.forEach(item->sb.append(item.getDefaultMessage()));
        }
        jsonResult.setErrorMessage(sb.toString());
        return jsonResult;
    }

    /*
     * 处理系统异常
     * */
    @ExceptionHandler(value = Exception.class)
    public @ResponseBody JsonResult constraintViolationExceptionHandler (Exception exception) {
        log.info("exception--->{}", exception);
        JsonResult jsonResult = new JsonResult();
        jsonResult.setErrorCode(ResultEnum.SYSTEM_EXCEPTION.getCode());
        jsonResult.setErrorMessage(ResultEnum.SYSTEM_EXCEPTION.getMsg());

        return jsonResult;
    }
}

返回信息处理类.

@Data
public class JsonResult<T> implements Serializable {

    private static final long serialVersionUID = -7866290240453139258L;

    //返回时间
    private String responseDate = null;

    //返回状态
    private String status = null;

    //错误码
    private String errorCode = null;

    //错误信息
    private String errorMessage = null;

    //接口返回对象
    private T responseBody = null;

    public JsonResult() {
        this.status = "SUCCESS";
        this.responseDate = (new Date()).toString();
    }

    public JsonResult(T responseBody) {
        this();
        this.status = "SUCCESS";
        this.responseBody = responseBody;
        this.errorCode = "";
        this.errorMessage = "";
    }

    public JsonResult<T> declareSuccess(T responseBody) {
        this.status = "SUCCESS";
        this.responseBody = responseBody;
        this.errorCode = "";
        this.errorMessage = "";

        return this;
    }

    public JsonResult<T> declareFailure(MyException e, T responseBody) {
        return declareFailure(e.getMessage(), e.getMessage(), responseBody);
    }

    public JsonResult<T> declareFailure(String errorCode, String errorMessage, T responseBody) {
        this.status = "FAILURE";
        this.errorCode = errorCode;
        this.errorMessage = errorMessage;
        this.responseBody = responseBody;

        return this;
    }
}

错误信息返回的枚举类.

public enum ResultEnum {

    SUCCESS("1000", "成功"),

    FAILED("1001", "失败"),

    PARAMS_ERROE("1002", "参数错误"),

    OTHER_EXCEPTION("1003", "其他错误"),

    SYSTEM_EXCEPTION("0000", "系统异常"),
    ;
    /*
     * 返回码
     */
    private String code;

    /*
     * 返回消息
     */
    private String msg;

    ResultEnum(String code, String msg) {
        this.code = code;
        this.msg = msg;
    }

    public String getCode() {
        return code;
    }

    public void setCode(String code) {
        this.code = code;
    }

    public String getMsg() {
        return msg;
    }

    public void setMsg(String msg) {
        this.msg = msg;
    }
}

测试的controller如下

@Slf4j
@RestController
public class TestControlelr {

@Autowired
private TestMapper testMapper;

@PostMapping("/exception/test")
public JsonResult exceptionTest(@Validated @RequestBody ParamTest paramTest){
TestPO testPO = new TestPO();
testPO.setNewTable("app_goods_info");
int total = testMapper.selectTotal(testPO);
System.out.println("total--->" + total);

JsonResult jsonResult = new JsonResult();
jsonResult.declareSuccess("异常测试接口:" + total);

return jsonResult;
}

@GetMapping("/exception/test/two")
public JsonResult exceptionTestTwo(){
int total = 10;
System.out.println("total--->" + total);
int temp = 1 / 0;
JsonResult jsonResult = new JsonResult();
jsonResult.declareSuccess("异常测试接口:" + total);
return jsonResult;
}

@PostMapping("/exception/test/three")
public JsonResult exceptionTestThree(){
int total = 10;
System.out.println("total--->" + total);
if (total > 8) {
throw new MyException(ResultEnum.FAILED.getCode(), "测试自定义异常");
}
JsonResult jsonResult = new JsonResult();
jsonResult.declareSuccess("异常测试接口:" + total);
return jsonResult;
}
}

测试的入参类如下:

@Data
public class ParamTest {

    /*
     * 名称
     */
    @NotNull(message = "名称不能为null")
    private String name;

    /*
     * 简介
     */
    @Length(max = 10, message = "简介长度最大为10")
    private String abs;
}

测试一：填写错误的参数，返回信息如下。

 测试二：测试在代码中写1/0的返回结果。

 测试三：主动抛出一个自定义异常，返回结果如下。

 在全局异常处理类中添加了三个方法，一个方法用来处理自定义异常的错误返回信息，一个方法用法用来返回参数校验的错误返回信息，

最后一个方法用来处理系统异常，三个方法都可以正常执行。真实开发中可以根据实际需要去添加一些自定义

异常信息，根据需要使用全局异常类来进行统一处理，这样可以很方便的从错误信息中分辨出是什么地方出现问题，便于快速排查问题。