个人博客开发之blog-api项目统一结果集api封装

前言

由于返回json api 格式接口，所以我们需要通过java bean封装一个统一数据返回格式，便于和前端约定交互，

状态码枚举ResultCode

package cn.soboys.core.ret;
import lombok.Getter;
/**
 * @author kenx
 * @version 1.0
 * @date 2021/6/17 15:35
 * 响应码枚举，对应HTTP状态码
 */
@Getter
public enum ResultCode {
    SUCCESS(200, "成功"),//成功
    //FAIL(400, "失败"),//失败
    BAD_REQUEST(400, "Bad Request"),
    UNAUTHORIZED(401, "认证失败"),//未认证
    NOT_FOUND(404, "接口不存在"),//接口不存在
    INTERNAL_SERVER_ERROR(500, "系统繁忙"),//服务器内部错误
    METHOD_NOT_ALLOWED(405,"方法不被允许"),
    /*参数错误:1001-1999*/
    PARAMS_IS_INVALID(1001, "参数无效"),
    PARAMS_IS_BLANK(1002, "参数为空");
    /*用户错误2001-2999*/
    private Integer code;
    private String message;
    ResultCode(int code, String message) {
        this.code = code;
        this.message = message;
    }
}

结果体Result

package cn.soboys.core.ret;
import lombok.Data;
import java.io.Serializable;
/**
 * @author kenx
 * @version 1.0
 * @date 2021/6/17 15:47
 * 统一API响应结果格式封装
 */
@Data
public class Result<T> implements Serializable {
    private static final long serialVersionUID = 6308315887056661996L;
    private Integer code;
    private String message;
    private T data;
    public Result setResult(ResultCode resultCode) {
        this.code = resultCode.getCode();
        this.message = resultCode.getMessage();
        return this;
    }
    public Result setResult(ResultCode resultCode, T data) {
        this.code = resultCode.getCode();
        this.message = resultCode.getMessage();
        this.setData(data);
        return this;
    }
}

响应结果方法工具类

package cn.soboys.core.ret;
/**
 * @author kenx
 * @version 1.0
 * @date 2021/6/17 16:30
 * 响应结果返回封装
 */
public class ResultResponse {
    private static final String DEFAULT_SUCCESS_MESSAGE = "SUCCESS";
    // 只返回状态
    public static Result success() {
        return new Result()
                .setResult(ResultCode.SUCCESS);
    }
    // 成功返回数据
    public static Result success(Object data) {
        return new Result()
                .setResult(ResultCode.SUCCESS, data);
    }
    // 失败
    public static Result failure(ResultCode resultCode) {
        return new Result()
                .setResult(resultCode);
    }
    // 失败
    public static Result failure(ResultCode resultCode, Object data) {
        return new Result()
                .setResult(resultCode, data);
    }
}

自定义解析controller拦截

注解@ResponseResult

package cn.soboys.core.ret;
import java.lang.annotation.*;
/**
 * @author kenx
 * @version 1.0
 * @date 2021/6/17 16:43
 * 统一包装接口返回的值 Result
 */
@Target({ElementType.TYPE, ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface ResponseResult {
}

请求拦截ResponseResultInterceptor

package cn.soboys.core.ret;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.HandlerInterceptor;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.lang.reflect.Method;
/**
 * @author kenx
 * @version 1.0
 * @date 2021/6/17 17:10
 * 请求拦截
 */
public class ResponseResultInterceptor implements HandlerInterceptor {
    //标记名称
    public static final String RESPONSE_RESULT_ANN = "RESPONSE-RESULT-ANN";
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        //请求方法
        if (handler instanceof HandlerMethod) {
            final HandlerMethod handlerMethod = (HandlerMethod) handler;
            final Class<?> clazz = handlerMethod.getBeanType();
            final Method method = handlerMethod.getMethod();
            //判断是否在对象上加了注解
            if (clazz.isAnnotationPresent(ResponseResult.class)) {
                //设置此请求返回体需要包装，往下传递，在ResponseBodyAdvice接口进行判断
                request.setAttribute(RESPONSE_RESULT_ANN, clazz.getAnnotation(ResponseResult.class));
                //方法体上是否有注解
            } else if (method.isAnnotationPresent(ResponseResult.class)) {
                //设置此请求返回体需要包装，往下传递，在ResponseBodyAdvice接口进行判断
                request.setAttribute(RESPONSE_RESULT_ANN, clazz.getAnnotation(ResponseResult.class));
            }
        }
        return true;
    }
}

请求全局解析ResponseResultHandler

package cn.soboys.core.ret;
import cn.soboys.core.utils.HttpContextUtil;
import com.alibaba.fastjson.JSON;
import lombok.extern.slf4j.Slf4j;
import org.springframework.core.MethodParameter;
import org.springframework.http.MediaType;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.servlet.mvc.method.annotation.ResponseBodyAdvice;
import javax.servlet.http.HttpServletRequest;
/**
 * @author kenx
 * @version 1.0
 * @date 2021/6/17 16:47
 * 全局统一响应返回体处理
 */
@Slf4j
@ControllerAdvice
public class ResponseResultHandler implements ResponseBodyAdvice<Object> {
    public static final String RESPONSE_RESULT_ANN = "RESPONSE-RESULT-ANN";
    /**
     * @param methodParameter
     * @param aClass
     * @return 此处如果返回false , 则不执行当前Advice的业务
     * 是否请求包含了包装注解 标记，没有直接返回不需要重写返回体，
     */
    @Override
    public boolean supports(MethodParameter methodParameter, Class<? extends HttpMessageConverter<?>> aClass) {
        HttpServletRequest request = HttpContextUtil.getRequest();
        //判断请求是否有包装标志
        ResponseResult responseResultAnn = (ResponseResult) request.getAttribute(RESPONSE_RESULT_ANN);
        return responseResultAnn == null ? false : true;
    }
    /**
     * @param body
     * @param methodParameter
     * @param mediaType
     * @param aClass
     * @param serverHttpRequest
     * @param serverHttpResponse
     * @return 处理响应的具体业务方法
     */
    @Override
    public Object beforeBodyWrite(Object body, MethodParameter methodParameter, MediaType mediaType, Class<? extends HttpMessageConverter<?>> aClass, ServerHttpRequest serverHttpRequest, ServerHttpResponse serverHttpResponse) {
        if (body instanceof Result) {
            return body;
        } else if (body instanceof String) {
            return JSON.toJSONString(ResultResponse.success(body));
        } else {
            return ResultResponse.success(body);
        }
    }
}

具体详细内容请参考我这篇文章Spring Boot 无侵入式 实现RESTful API接口统一JSON格式返回

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