Springboot+異常處理

1.定義異常接口

public interface ResultCode {
    boolean success();
    int code();
    String msg();
}

2.定義異常枚舉

@ToString
public enum CommonCode implements ResultCode {

    SUCCESS(true,200,"請求成功！"),
    FAILED(false,9999,"請求失敗！"),
    INVALID_PARAM(false,9001,"非法入參！");
    boolean success;
    int code;
    String msg;

    CommonCode(boolean success, int code, String msg) {
        this.success = success;
        this.code = code;
        this.msg = msg;
    }
    @Override
    public boolean success() {
        return success;
    }
    @Override
    public int code() {
        return code;
    }
    @Override
    public String msg() {
        return msg;
    }
}

3.返回基本數據類型

public class ResponseResult{

    private boolean success;
    private int code;
    private String message;
    private Object data;

    public ResponseResult(){}

    public ResponseResult(boolean success, int code, String message, Object data) {
        this.success = success;
        this.code = code;
        this.message = message;
        this.data = data;
    }

    public ResponseResult(ResultCode resultCode) {
        this.success = resultCode.success();
        this.code = resultCode.code();
        this.message = resultCode.msg();
    }
//getter setter
}

4.自定義異常

public class CustomException extends RuntimeException {
    private ResultCode resultCode;
    public ResultCode getResultCode() {
        return resultCode;
    }
    public CustomException(ResultCode resultCode) {
        //異常信息爲錯誤代碼+異常信息(自定義咱們的異常信息格式)
        this.resultCode = resultCode;
    }
}

5.異常轉化

public class ExceptionCast {
    public static void cast(ResultCode resultCode){
        throw new CustomException(resultCode);
    }
}

6.異常統一處理

@ControllerAdvice
public class ExceptionCatch {
    //捕獲 CustomException異常
    @ExceptionHandler(CustomException.class)
    @ResponseBody
    public ResponseResult customException(CustomException e) {
        e.printStackTrace();
        ResultCode resultCode = e.getResultCode();
        ResponseResult rr = new ResponseResult(resultCode);
        return rr;
    }

    //使用EXCEPTIONS存放異常類型和錯誤代碼映射 ImmutableMap的特色是一旦建立不可改變 而且線程安全
    // 定義map 配置異常類型所對應的錯誤代碼
    private static ImmutableMap<Class<? extends Throwable>, ResultCode> EXCEPTIONS;
    //定義map的builder對象 去構建ImmutableMap對象
    protected static ImmutableMap.Builder<Class<? extends Throwable>, ResultCode> builder = ImmutableMap.builder();

    //使用build來構建一個y異常類型和錯誤代碼異常
    @ExceptionHandler(Exception.class)
    @ResponseBody
    public ResponseResult exception(Exception e) {
        e.printStackTrace();
        if (EXCEPTIONS == null) {
            EXCEPTIONS = builder.build(); //EXCEPTIONS構建成功
        }
        //從EXCEPTIONS中找異常類型所對因的錯誤代碼 若是找到了將錯誤代碼相應給用戶 若是找不到響應9999異常
        ResultCode resultCode = EXCEPTIONS.get(e.getClass());
        if (resultCode != null) {
            return new ResponseResult(resultCode);
        } else {
            return new ResponseResult(CommonCode.FAILED);
        }
    }

    static {
        builder.put(HttpMessageNotReadableException.class, CommonCode.INVALID_PARAM);
    }
}

7.SpringBoot起動掃面自定義切面類

@SpringBootApplication
@ComponentScan(basePackages = {"exception","demo.controller"})public class ActivitiApplication {    public static void main(String[] args) {        SpringApplication.run(ActivitiApplication.class, args);    }}