Spring AOP 返回结果注入业务数据

原创已于 2022-06-09 16:22:27 修改 · 589 阅读

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#spring #java #restful

于 2021-09-07 18:14:01 首次发布

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该博客介绍了如何使用Spring AOP（面向切面编程）来实现在返回数据中注入业务值。通过定义注解`@AutoGiftCoupon`，在方法执行前后进行拦截，解析并注入赠品券信息。在解析过程中，首先将返回对象转换为JSON，然后根据自定义字段填充数据，并调用`getGiftProDtoMap`方法获取赠品产品详情。整个过程提高了代码的可维护性和灵活性。

一、数据返回后切面注入业务值

package com.test.aspect;

import com.alibaba.fastjson.JSONObject;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;

import lombok.extern.slf4j.Slf4j;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Pointcut;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Component;

import java.util.*;

/**
 * @Author Andy
 * @Date 2021/9/7
 */
@Aspect
@Component
@Slf4j
public class GiftAspect {

    private final static String FILED_GIFT_PROD_ID = "giftProdId";
    private final static String FILED_COUPON_TYPE = "couponType";
    private final static String FILED_GIFT_PRO_DTO = "giftProDto ";

    @Autowired
    private final ProductMapper productMapper;

    @Pointcut("@annotation(com.test.aspect.annotation.AutoGiftCoupon)")
    public void giftCouponPointCut() {

    }

    @Around("giftCouponPointCut()")
    public Object doAround(ProceedingJoinPoint pjp) throws Throwable {
        long time1 = System.currentTimeMillis();
        Object result = pjp.proceed();
        long time2 = System.currentTimeMillis();
        log.debug("获取JSON数据 耗时：" + (time2 - time1) + "ms");
        long start = System.currentTimeMillis();
        this.parseCoupon(result);
        long end = System.currentTimeMillis();
        log.debug("解析注入JSON数据  耗时" + (end - start) + "ms");
        return result;
    }

    /**
     * 解析赠品券
     *
     * @param response
     */
    private void parseCoupon(Object response) {
        if (response instanceof ResponseEntity) {
            Object result = ((ResponseEntity)response).getBody();
            if (result instanceof IPage || result instanceof List) {
                List<Object> list;
                if (result instanceof IPage) {
                    list = ((IPage)result).getRecords();
                } else {
                    list = (List<Object>)result;
                }
                List<JSONObject> items = new ArrayList<>();
                Set<Long> set = new HashSet<>();
                for (Object record : list) {
                    ObjectMapper mapper = new ObjectMapper();
                    String json = "{}";
                    try {
                        //解决@JsonFormat注解解析不了的问题详见SysAnnouncement类的@JsonFormat
                        json = mapper.writeValueAsString(record);
                    } catch (JsonProcessingException e) {
                        log.error("json解析失败" + e.getMessage(), e);
                    }
                    JSONObject item = JSONObject.parseObject(json);
                 /*   自定义字段注解获取数据，用来填充
                 for (Field field : getAllFields(record)) {
                        //update-end--Author:scott  -- Date:20190603 ----for：解决继承实体字段无法翻译问题------
                        if (field.getAnnotation(Dict.class) != null) {
                            String code = field.getAnnotation(Dict.class).dicCode();
                            String text = field.getAnnotation(Dict.class).dicText();
                            String table = field.getAnnotation(Dict.class).dictTable();
                            String key = String.valueOf(item.get(field.getName()));
                            //翻译字典值对应的txt
                            String textValue = translateDictValue(code, text, table, key);
                            item.put(field.getName() + CommonConstant.DICT_TEXT_SUFFIX, textValue);
                        }
                    }*/

                    Integer couponType = item.getInteger(FILED_COUPON_TYPE);
                    if (CouponType.C2G.value().equals(couponType)) {
                        set.add(item.getLong(FILED_GIFT_PROD_ID));
                    }
                    items.add(item);
                }
                ((IPage) ((ResponseEntity) response).getBody()).setRecords(items);
                Map<Long, GiftProDto> map = getGiftProDtoMap(set);
                items.forEach(item -> {
                    Integer couponType = item.getInteger(FILED_COUPON_TYPE);
                    if (CouponType.C2G.value().equals(couponType)) {
                        Long giftProdId = item.getLong(FILED_GIFT_PROD_ID);
                        if (giftProdId != null) {
                            item.put(FILED_GIFT_PRO_DTO, map.get(giftProdId));
                        }
                    }
                });

            } else {
                ObjectMapper mapper = new ObjectMapper();
                String json = "{}";
                try {
                    //解决@JsonFormat注解解析不了的问题详见SysAnnouncement类的@JsonFormat
                    json = mapper.writeValueAsString(result);
                } catch (JsonProcessingException e) {
                    log.error("json解析失败" + e.getMessage(), e);
                }
                JSONObject item = JSONObject.parseObject(json);
                Integer couponType = item.getInteger(FILED_COUPON_TYPE);
                if (CouponType.C2G.value().equals(couponType)) {
                    Long giftProdId = item.getLong(FILED_GIFT_PROD_ID);
                    if (giftProdId != null) {
                        GiftProDto giftProDto = productMapper.getGiftProInfo(giftProdId);
                        item.put(FILED_GIFT_PRO_DTO, giftProDto);
                    }
                }

            }
        }

    }

    private Map<Long, GiftProDto> getGiftProDtoMap(Set<Long> set) {
        Map<Long, GiftProDto> map = new HashMap<>();
        set.forEach(item -> {
            GiftProDto giftProDto = productMapper.getGiftProInfo(item);
            map.put(item, giftProDto);
        });
        return map;
    }

}

二、注解声明类，只需要在接口上加上注解即可

package com.test.aspect.annotation;

import java.lang.annotation.*;

/**
 * @Author Andy
 * @Date 2021/9/7
 */
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface AutoGiftCoupon {
    /**
     * 赠品券标识
     *
     * @return
     */
    String value() default "";
}

三、利用反射获取字段值

/**
	 * 获取类的所有属性，包括父类
	 * 
	 * @param object
	 * @return
	 */
	public static Field[] getAllFields(Object object) {
		Class<?> clazz = object.getClass();
		List<Field> fieldList = new ArrayList<>();
		while (clazz != null) {
			fieldList.addAll(new ArrayList<>(Arrays.asList(clazz.getDeclaredFields())));
			clazz = clazz.getSuperclass();
		}
		Field[] fields = new Field[fieldList.size()];
		fieldList.toArray(fields);
		return fields;
	}