SpringBoot统一返回R类

JokerDJ

发布于 2023-11-27 15:43:08

2430

发布于 2023-11-27 15:43:08

文章被收录于专栏：JokerDJJokerDJ

在项目开发过程中，很难避免返回各种各样的结果，就会导致前端渲染时造成混乱，怎么统一返回呢？

编写R.java Object

/**
 * @Author Joker DJ
 * @Date 2021/8/7 20:58
 * @Version 1.0
 */

public class R {
    /**
     *标识返回状态
     */
    private Integer code;

    /**
     * 标识返回内容
     */
    private Object data;
    /**
     * 标识返回消息
     */
    private String message;


    /**
     * 成功返回
     * @param data
     * @return
     */
    public static R ok(Object data){
        return new R(RHttpStatusEnum.SUCCESS.getCode(),data,RHttpStatusEnum.SUCCESS.getMessage());
    }

    /**
     * 成功返回
     * @param data
     * @return
     */
    public static R ok(Object data,String message){
        return new R(RHttpStatusEnum.SUCCESS.getCode(),data,message);
    }

    /**
     * 失败返回
     * @param rHttpStatusEnum
     * @return
     */
    public static R error(RHttpStatusEnum rHttpStatusEnum){
        return new R(rHttpStatusEnum.getCode(),null,rHttpStatusEnum.getMessage());
    }
    public static R error(Integer code,String message){
        R r = new R();
        r.code(code);
        r.data(null);
        r.message(message);
        return r;
    }



    public R() {

    }

    public R(Integer code, Object data, String message) {
        this.code = code;
        this.data = data;
        this.message = message;
    }

    public Integer getCode() {
        return code;
    }

    public R code(Integer code) {
        this.code = code;
        return this;
    }

    public Object getData() {
        return data;
    }

    public R data(Object data) {
        this.data = data;
        return this;
    }

    public String getMessage() {
        return message;
    }

    public R message(String message) {
        this.message = message;
        return this;
    }
}

编写R.java 泛型

package com.dj.rvo.Vo;

/**
 * @Author Joker DJ
 * @Date 2021/8/7 20:58
 * @Version 1.0
 */

public class RT<T> {
    /**
     * 标识返回状态
     */
    private Integer code;

    /**
     * 标识返回内容
     */
    private T data;
    /**
     * 标识返回消息
     */
    private String message;


    /**
     * 成功返回
     *
     * @param data
     * @return
     */
    public static <T> RT ok(T data) {
        return new RT(RHttpStatusEnum.SUCCESS.getCode(), data, RHttpStatusEnum.SUCCESS.getMessage());
    }

    /**
     * 成功返回
     *
     * @param data
     * @return
     */
    public static <T> RT ok(T data, String message) {
        return new RT(RHttpStatusEnum.SUCCESS.getCode(), data, message);
    }

    /**
     * 失败返回
     *
     * @param rHttpStatusEnum
     * @return
     */
    public static RT error(RHttpStatusEnum rHttpStatusEnum) {
        return new RT(rHttpStatusEnum.getCode(), null, rHttpStatusEnum.getMessage());
    }
    public static RT error(Integer code,String message){
        RT r = new RT();
        r.code(code);
        r.data(null);
        r.message(message);
        return r;
    }

    public RT() {

    }

    public RT(Integer code, T data, String message) {
        this.code = code;
        this.data = data;
        this.message = message;
    }

    public Integer getCode() {
        return code;
    }

    public RT code(Integer code) {
        this.code = code;
        return this;
    }

    public Object getData() {
        return data;
    }

    public RT data(T data) {
        this.data = data;
        return this;
    }

    public String getMessage() {
        return message;
    }

    public RT message(String message) {
        this.message = message;
        return this;
    }
}

编写返回枚举 RHttpStatusEnum

package com.dj.rvo.Vo;

/**
 * @Author Joker DJ
 * @Date 2021/8/7 21:16
 * @Version 1.0
 */
public enum RHttpStatusEnum {

    SUCCESS(200,"success"),
    HTTP_NOT_FOUND(404,"未找到相关内容"),
    SERVER_ERROR( 500, "服务器忙，请稍后在试");
    private final int code;
    private final String message;
    RHttpStatusEnum(Integer code,String message){
        this.code=code;
        this.message=message;
    }

    public int getCode() {
        return code;
    }

    public String getMessage() {
        return message;
    }

}

测试

/**
     * 返回错误信息
     * @return
     */
    public R test1(){
        return R.error(RHttpStatusEnum.HTTP_NOT_FOUND);
    }

    /**
     * 返回成功信息
     * @return
     */
    public R test2() {
        return R.ok("成功");
    }
    public R test3() {
        return R.ok("数据","信息");
    }

问题：如果都返回R类太强制了；通过通知来封装R类

编写 ResultResponseHandler

package com.dj.rvo.Handler;

import com.dj.rvo.Utils.JsonUtil;
import com.dj.rvo.Vo.R;
import com.fasterxml.jackson.databind.ObjectMapper;
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;

/**
 * @Author Joker DJ
 * @Date 2021/8/7 21:53
 * @Version 1.0
 */
@ControllerAdvice(basePackages = "com.dj.rvo.Controller")// 绑定的Controller包的权限定名 例如:com.dj.Controller
public class ResultResponseHandler implements ResponseBodyAdvice<Object> {
    @Override
    public boolean supports(MethodParameter methodParameter, Class<? extends HttpMessageConverter<?>> aClass) {
        return true;
    }

    @Override
    public Object beforeBodyWrite(Object o, MethodParameter methodParameter, MediaType mediaType, Class<? extends HttpMessageConverter<?>> aClass, ServerHttpRequest serverHttpRequest, ServerHttpResponse serverHttpResponse) {
        // 对请求的结果在这里统一返回和处理
        if (o instanceof ErrorHandler) {
            // 1、如果返回的结果是一个异常的结果，就把异常返回的结构数据倒腾到R.fail里面即可
            ErrorHandler errorHandler = (ErrorHandler) o;
            return R.error(errorHandler.getStatus(), errorHandler.getMessage());
        } else if (o instanceof String) {
            try {
                // 2、因为springmvc数据转换器对String是有特殊处理 StringHttpMessageConverter
                ObjectMapper objectMapper = new ObjectMapper();
                R r = R.ok(o);
                return objectMapper.writeValueAsString(r);
            }catch ( Exception ex){
                ex.printStackTrace();
            }
        }
        return R.ok(o);
    }
}

编写自定义异常返回ErrorHandler

package com.dj.rvo.Handler;

import com.dj.rvo.Vo.RHttpStatusEnum;
/**
 *
 * 功能描述: 异常返回
 *
 * @param:
 * @return:
 * @auther: Joker
 * @date: 2021/8/7 22:25
 */
public class ErrorHandler {
    // ErrorHandler === R 答案：不想破坏R类。
    // 异常的状态码，从枚举中获得
    private Integer status;
    // 异常的消息，写用户看得懂的异常，从枚举中得到
    private String message;
    // 异常的名字
    private String exception;

    /**
     * 对异常处理进行统一封装
     *
     * @param resultCodeEnum 异常枚举
     * @param throwable 出现异常
     * @param message 异常的消息 null /by zero
     * @return
     */
    public static ErrorHandler fail(RHttpStatusEnum resultCodeEnum, Throwable throwable, String message) {
        ErrorHandler errorHandler = ErrorHandler.fail(resultCodeEnum, throwable);
        errorHandler.setMessage(message);
        return errorHandler;
    }

    /**
     * 对异常枚举进行封装
     *
     * @param resultCodeEnum
     * @param throwable
     * @return
     */
    public static ErrorHandler fail(RHttpStatusEnum resultCodeEnum, Throwable throwable) {
        ErrorHandler errorHandler = new ErrorHandler();
        errorHandler.setMessage(resultCodeEnum.getMessage());
        errorHandler.setStatus(resultCodeEnum.getCode());
        errorHandler.setException(throwable.getClass().getName());
        return errorHandler;
    }

    public Integer getStatus() {
        return status;
    }

    public void setStatus(Integer status) {
        this.status = status;
    }

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

    public String getException() {
        return exception;
    }

    public void setException(String exception) {
        this.exception = exception;
    }
}

编写异常通知类 GlobalRestExceptionHandler

package com.dj.rvo.Handler;

import com.dj.rvo.Vo.RHttpStatusEnum;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.validation.FieldError;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;

import javax.servlet.http.HttpServletRequest;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 *
 * 功能描述: 统一异常处理
 *
 * @param:
 * @return:
 * @auther: Joker
 * @date: 2021/8/7 22:30
 */
@RestControllerAdvice
public class GlobalRestExceptionHandler {

    /**
     * 对服务器端出现500异常进行统一处理
     * 缺点：不明确
     * 场景：
     */
    @ExceptionHandler(Throwable.class)
    public ErrorHandler makeExcepton(Throwable e, HttpServletRequest request) {
        ErrorHandler errorHandler = ErrorHandler.fail(RHttpStatusEnum.SERVER_ERROR, e);
        return errorHandler;
    }

    /**
     * 对服务器端出现500异常进行统一处理
     * 缺点：明确异常信息
     */
    @ExceptionHandler(BusinessException.class)
    public ErrorHandler makeOrderException(BusinessException businessException, HttpServletRequest request) {
        ErrorHandler errorHandler = new ErrorHandler();
        errorHandler.setMessage(businessException.getMessage());
        errorHandler.setStatus(businessException.getCode());
        return errorHandler;
    }

    /**
     * 对验证的统一异常进行统一处理
     */
    @ExceptionHandler(MethodArgumentNotValidException.class)
    public ErrorHandler handlerValiator(MethodArgumentNotValidException e, HttpServletRequest request) throws JsonProcessingException {
        // 1: 从MethodArgumentNotValidException提取验证失败的所有的信息。返回一个List<FieldError>
        List<FieldError> fieldErrors = e.getBindingResult().getFieldErrors();
        // 2: 把fieldErrors中，需要的部分提出出来进行返回
        List<Map<String, String>> mapList = toValidatorMsg(fieldErrors);
        // 3: 把需要的异常信息转换成json进行返回
        ObjectMapper objectMapper = new ObjectMapper();
        String mapJson = objectMapper.writeValueAsString(mapList);
        ErrorHandler errorHandler = ErrorHandler.fail(RHttpStatusEnum.SERVER_ERROR, e, mapJson);
        return errorHandler;
    }


    /**
     * 对验证异常进行统一处理提取需要的部分
     *
     * @param fieldErrorList
     * @return
     */
    private List<Map<String, String>> toValidatorMsg(List<FieldError> fieldErrorList) {
        List<Map<String, String>> mapList = new ArrayList<>();
        // 循环提取
        for (FieldError fieldError : fieldErrorList) {
            Map<String, String> map = new HashMap<>();
            // 获取验证失败的属性
            map.put("field", fieldError.getField());
            // 获取验证失败的的提示信息
            map.put("msg", fieldError.getDefaultMessage());

            mapList.add(map);
        }
        return mapList;
    }


}

自定义异常 BusinessException

package com.dj.rvo.Handler;

import com.dj.rvo.Vo.RHttpStatusEnum;
/**
 *
 * 功能描述: 
 *
 * @param: 
 * @return: 
 * @auther: Joker
 * @date: 2021/8/7 22:47
 */
public class BusinessException extends RuntimeException {
    private Integer code;
    private String message;
    public BusinessException(RHttpStatusEnum resultCodeEnum) {
        this.code = resultCodeEnum.getCode();
        this.message = resultCodeEnum.getMessage();
    }
    public BusinessException(Integer code, String message) {
        this.code = code;
        this.message = message;
    }

    public Integer getCode() {
        return code;
    }

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

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }
}

测试

/**
 * @Author Joker DJ
 * @Date 2021/8/7 22:45
 * @Version 1.0
 */
@RestController
public class Test {
    @RequestMapping("/test1")
    public Map<String,Object> test1(){
        Map<String, Object> hashMap = new HashMap<>();
        hashMap.put("username","JokerDJ");
        return hashMap;
    }

    @RequestMapping("/test2")
    public String test2(){
        boolean flag = false;
        System.out.println(1/0);
        return "成功";
    }

    @RequestMapping("/test3")
    public String test3(){
        boolean flag = false;
        if(!flag){
            throw new BusinessException(500,"系统异常");
        }
        return "成功";
    }
}

相关工具

package com.dj.rvo.Utils;

import org.codehaus.jackson.map.DeserializationConfig;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.map.SerializationConfig;
import org.codehaus.jackson.map.annotate.JsonSerialize.Inclusion;
import org.codehaus.jackson.type.JavaType;
import org.codehaus.jackson.type.TypeReference;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.util.StringUtils;

import java.text.SimpleDateFormat;

/**
 * by mofeng
 * <dependency>
 * <groupId>com.fasterxml.jackson.dataformat</groupId>
 * <artifactId>jackson-dataformat-avro</artifactId>
 * </dependency>
 *
 * <dependency>
 * <groupId>org.apache.commons</groupId>
 * <artifactId>commons-lang3</artifactId>
 * <version>3.6</version>
 * </dependency>
 */
public class JsonUtil {

    private static ObjectMapper objectMapper = new ObjectMapper();
    private static Logger log = LoggerFactory.getLogger(JsonUtil.class);

    static {
        // 对象的所有字段全部列入
        objectMapper.setSerializationInclusion(Inclusion.ALWAYS);

        // 取消默认转换timestamps形式
        objectMapper.configure(SerializationConfig.Feature.WRITE_DATES_AS_TIMESTAMPS, false);

        // 忽略空Bean转json的错误
        objectMapper.configure(SerializationConfig.Feature.FAIL_ON_EMPTY_BEANS, false);

        // 所有的日期格式都统一为以下的样式，即yyyy-MM-dd HH:mm:ss
        objectMapper.setDateFormat(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"));

        // 忽略 在json字符串中存在，但是在java对象中不存在对应属性的情况。防止错误
        objectMapper.configure(DeserializationConfig.Feature.FAIL_ON_UNKNOWN_PROPERTIES, false);

        // 精度的转换问题
        objectMapper.configure(DeserializationConfig.Feature.USE_BIG_DECIMAL_FOR_FLOATS, true);

        objectMapper.configure(DeserializationConfig.Feature.ACCEPT_SINGLE_VALUE_AS_ARRAY, true);
    }


    public static <T> String obj2String(T obj) {
        if (obj == null) {
            return null;
        }
        try {
            return obj instanceof String ? (String) obj : objectMapper.writeValueAsString(obj);
        } catch (Exception e) {
            log.warn("Parse Object to String error", e);
            return null;
        }
    }

    public static <T> String obj2StringPretty(T obj) {
        if (obj == null) {
            return null;
        }
        try {
            return obj instanceof String ? (String) obj
                    : objectMapper.writerWithDefaultPrettyPrinter().writeValueAsString(obj);
        } catch (Exception e) {
            log.warn("Parse Object to String error", e);
            return null;
        }
    }

    public static <T> T string2Obj(String str, Class<T> clazz) {
        if (StringUtils.isEmpty(str) || clazz == null) {
            return null;
        }

        try {
            return clazz.equals(String.class) ? (T) str : objectMapper.readValue(str, clazz);
        } catch (Exception e) {
            log.warn("Parse String to Object error", e);
            return null;
        }
    }

    public static <T> T string2Obj(String str, TypeReference<T> typeReference) {
        if (StringUtils.isEmpty(str) || typeReference == null) {
            return null;
        }
        try {
            return (T) (typeReference.getType().equals(String.class) ? str
                    : objectMapper.readValue(str, typeReference));
        } catch (Exception e) {
            log.warn("Parse String to Object error", e);
            return null;
        }
    }

    public static <T> T string2Obj(String str, Class<?> collectionClass, Class<?>... elementClasses) {
        JavaType javaType = objectMapper.getTypeFactory().constructParametricType(collectionClass, elementClasses);
        try {
            return objectMapper.readValue(str, javaType);
        } catch (Exception e) {
            log.warn("Parse String to Object error", e);
            return null;
        }
    }

    public static void main(String[] args) {
        //String json = "{\"name\":\"Geely\",\"color\":\"blue\",\"id\":1274670369972846594}";
        /*
         * User user = new User(); user.setId(2);
         * user.setAccount("geely@happymmall.com"); user.setCreateTime(new Date());
         * String userJsonPretty = JsonUtil.obj2StringPretty(user);
         * log.info("userJson:{}",userJsonPretty);
         *
         *
         * User user2 = JsonUtil.string2Obj(userJsonPretty, User.class);
         * System.out.println(user2);
         */

    }

}

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原始发表：2023-11-27，如有侵权请联系 cloudcommunity@tencent.com 删除

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