Java项目实战7——增强类

@TOC
在项目的建设过程中，我们需要统一一些公共部分的东西，比如返回体、异常处理、异常错误码等等。

定义异常码

package com.hao.enums;

import lombok.AllArgsConstructor;
import lombok.Getter;

/**
 * 接口状态码枚举
 *
 * @author lihao
 * @since 2022-7-4 21:08:56
 **/
@Getter
@AllArgsConstructor
public enum StatusCodeEnum {

    /**
     * 成功
     */
    SUCCESS(20000, "操作成功"),
    /**
     * 失败
     */
    FAIL(51000, "操作失败"),
    SYSTEM_ERROR(50000, "系统异常"),
    VALID_ERROR(52000, "参数格式不正确");

    /**
     * 状态码
     */
    private final Integer code;

    /**
     * 描述
     */
    private final String desc;

}

JAVA

统一返回体

package com.hao.vo;

import com.hao.enums.StatusCodeEnum;
import lombok.Data;

import static com.hao.enums.StatusCodeEnum.FAIL;
import static com.hao.enums.StatusCodeEnum.SUCCESS;


/**
 * 接口返回类
 *
 * @author lihao
 * @since 2022-7-4 21:07:10
 */
@Data
public class Result<T> {

    /**
     * 返回状态
     */
    private Boolean flag;
    /**
     * 返回码
     */
    private Integer code;
    /**
     * 返回信息
     */
    private String message;
    /**
     * 返回数据
     */
    private T data;

    public static <T> Result<T> ok() {
        return restResult(true, null, SUCCESS.getCode(), SUCCESS.getDesc());
    }

    public static <T> Result<T> ok(T data) {
        return restResult(true, data, SUCCESS.getCode(), SUCCESS.getDesc());
    }

    public static <T> Result<T> ok(T data, String message) {
        return restResult(true, data, SUCCESS.getCode(), message);
    }

    public static <T> Result<T> fail() {
        return restResult(false, null, FAIL.getCode(), FAIL.getDesc());
    }

    public static <T> Result<T> fail(StatusCodeEnum statusCodeEnum) {
        return restResult(false, null, statusCodeEnum.getCode(), statusCodeEnum.getDesc());
    }

    public static <T> Result<T> fail(String message) {
        return restResult(false, message);
    }

    public static <T> Result<T> fail(T data) {
        return restResult(false, data, FAIL.getCode(), FAIL.getDesc());
    }

    public static <T> Result<T> fail(T data, String message) {
        return restResult(false, data, FAIL.getCode(), message);
    }

    public static <T> Result<T> fail(Integer code, String message) {
        return restResult(false, null, code, message);
    }

    private static <T> Result<T> restResult(Boolean flag, String message) {
        Result<T> apiResult = new Result<>();
        apiResult.setFlag(flag);
        apiResult.setCode(flag ? SUCCESS.getCode() : FAIL.getCode());
        apiResult.setMessage(message);
        return apiResult;
    }

    private static <T> Result<T> restResult(Boolean flag, T data, Integer code, String message) {
        Result<T> apiResult = new Result<>();
        apiResult.setFlag(flag);
        apiResult.setData(data);
        apiResult.setCode(code);
        apiResult.setMessage(message);
        return apiResult;
    }

}

JAVA

统一业务异常类

package com.hao.advice;

import com.hao.enums.StatusCodeEnum;
import lombok.AllArgsConstructor;
import lombok.Getter;

import static com.hao.enums.StatusCodeEnum.FAIL;


/**
 * 业务异常
 *
 * @author lihao
 * @since 2022-7-4 21:11:22
 */
@Getter
@AllArgsConstructor
public class BizException extends RuntimeException {

    /**
     * 错误码
     */
    private Integer code = FAIL.getCode();

    /**
     * 错误信息
     */
    private final String message;

    public BizException(String message) {
        this.message = message;
    }

    public BizException(StatusCodeEnum statusCodeEnum) {
        this.code = statusCodeEnum.getCode();
        this.message = statusCodeEnum.getDesc();
    }


}
JAVA

统一异常处理拦截器

package com.hao.advice;

import com.hao.vo.Result;
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;

import java.util.Objects;

import static com.hao.enums.StatusCodeEnum.SYSTEM_ERROR;
import static com.hao.enums.StatusCodeEnum.VALID_ERROR;

/**
 * @author lihao
 */
@Slf4j
@RestControllerAdvice
public class ControllerAdviceHandler {

    /**
     * 处理服务异常
     *
     * @param e 异常
     * @return 接口异常信息
     */
    @ExceptionHandler(value = BizException.class)
    public Result<?> errorHandler(BizException e) {
        return Result.fail(e.getCode(), e.getMessage());
    }

    /**
     * 处理参数校验异常
     *
     * @param e 异常
     * @return 接口异常信息
     */
    @ExceptionHandler(MethodArgumentNotValidException.class)
    public Result<?> errorHandler(MethodArgumentNotValidException e) {
        return Result.fail(VALID_ERROR.getCode(), Objects.requireNonNull(e.getBindingResult().getFieldError()).getDefaultMessage());
    }

    /**
     * 处理系统异常
     *
     * @param e 异常
     * @return 接口异常信息
     */
    @ExceptionHandler(value = Exception.class)
    public Result<?> errorHandler(Exception e) {
        e.printStackTrace();
        return Result.fail(SYSTEM_ERROR.getCode(), SYSTEM_ERROR.getDesc());
    }

}

JAVA

测试

测试返回体和异常


@GetMapping("/listAll")
@Operation(summary = "获取所有用户", description = "获取所有的用户信息，不分页")
public Result<List<User>> listAll() {
    Result<List<User>> result = Result.ok();
    result.setData(userService.list());
    return result;
}

@GetMapping("/testException")
@Operation(summary = "测试异常", description = "异常测试，全局拦截器测试")
public Result<List<User>> testException() {
    throw new BizException("系统崩了，出问题啦！！！！");
}

JAVA