转换基础信息工具

• 一、背景
• 二、主要功能
• 三、如何实现
  • 工具类
  • 接口
  • 注解
  • Order-service
    • order-service 自定义解析器

一、背景

因项目中在Controller层使用ThreadLocal，不能执行remove() 方法会带来内存泄漏和数据串的问题，现提出转换基础信息工具类 

BeanTransformResolver

二、主要功能

• 手动转换基础信息

在Service层调用 BeanTransformResolver.execute(obj);

• 自动转换基础信息
        在Controller层方法上添加注解@TransformBean

三、如何实现

注解

TransformBean

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/**  * @description: 转换Bean , 继承ResponseBodyAdvice ，重写beforeBodyWrite，实现自动转换  * @create: 2019-12-09 19:32  **/ @Retention(RetentionPolicy.RUNTIME) @Target({ElementType.FIELD, ElementType.METHOD}) public @interface TransformBean {     /**      * 转换最大层级 默认为3 此值只在修饰Controller层的方法上才生效      *      * @return      */     int maxLevel() default 3; }

TransformField

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/**  * @description: 转换字段  **/ @Retention(RetentionPolicy.RUNTIME) @Target({ElementType.FIELD}) public @interface TransformField {     /**      * 转换类型      * @return      */     String type();     /**      * 源字段名      * @return      */     String sourceFieldName();     /**      * 转换字段名      * @return      */     String transformFieldName(); }

接口

TransformResolver

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/**  * @description: 转换解析器  * @author: yexianliang  * @create: 2019-12-10 09:27  **/ public interface TransformResolver {     Map<Long, Object> execute(Set<Long> ids); }

工具类

BeanTransformResolver 折叠源码

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/**  * @description:   * @create: 2019-12-09 19:32  **/ @Component @Slf4j public class BeanTransformResolver {     /**      * 默认最大层级      */     private Integer DEFAULT_MAX_LEVEL = 3;     /**      * 初始级别      */     private Integer INIT_LEVEL = 1;     @Autowired     private FeignRunnable FeignRunnable;     public Object execute(Object obj) {         return transform(obj, this.DEFAULT_MAX_LEVEL);     }     public Object execute(Object obj, Integer maxLevel) {         if (maxLevel == null || maxLevel < this.INIT_LEVEL) {             maxLevel = this.DEFAULT_MAX_LEVEL;         }         return this.transform(obj, maxLevel);     }     private Object transform(Object obj, Integer maxLevel) {         log.debug("Method:transform start ... ");         if (obj == null) {             return obj;         }         Object pendingObj = this.getPendingObj(obj);         Map<String, Set<Long>> transformResolverMap = new HashMap<>();         this.findSourceFieldValues(pendingObj, transformResolverMap, this.INIT_LEVEL, maxLevel);         log.debug("Method:transform transformResolverMap:{}", JSON.toJSONString(transformResolverMap));         if (transformResolverMap.isEmpty()) {             return obj;         }         CountDownLatch countDownLatch = new CountDownLatch(transformResolverMap.size());         for (String type : transformResolverMap.keySet()) {             this.findDataAndTransformField(pendingObj, transformResolverMap, type, countDownLatch, maxLevel);         }         try {             countDownLatch.await();         } catch (InterruptedException e) {             log.error("Method:transform countDownLatch.await error:{}", e);         }         log.debug("Method:transform end ... ");         return obj;     }     /**      * 获取待处理对象      *      * @param obj      * @return      */     private Object getPendingObj(Object obj) {         // 处理PageInfo类型的列表         if (obj.getClass().equals(PageInfo.class)) {             try {                 Field items = obj.getClass().getDeclaredField("items");                 items.setAccessible(true);                 return items.get(obj);             } catch (NoSuchFieldException e) {                 log.error("Method:getPendingObj NoSuchFieldException:{}", e);             } catch (IllegalAccessException e) {                 log.error("Method:getPendingObj IllegalAccessException:{}", e);             } catch (Exception e) {                 log.error("Method:getPendingObj Exception:{}", e);             }         }         return obj;     }     /**      * 获取sourceField源字段值      *      * @param obj      *            对象      * @param transformResolverMap      *            存储不同转换类型的源字段值的集合 key为TransformField 注解上type的值 ； value为TransformField注解上sourceFieldName      *            对应的值的集合      * @param level      *            层级      */     private void findSourceFieldValues(Object obj, Map<String, Set<Long>> transformResolverMap, Integer level,                                        Integer maxLevel) {         if (obj == null) {             return;         }         if (obj instanceof List) {             if (level < maxLevel) {                 Iterator iterator = ((List)obj).iterator();                 while (iterator.hasNext()) {                     this.findSourceFieldValues(iterator.next(), transformResolverMap, level, maxLevel);                 }             }             return;         }         resolverSourceFieldValues(obj, transformResolverMap, level, maxLevel, obj.getClass());     }     private void resolverSourceFieldValues(Object obj, Map<String, Set<Long>> transformResolverMap, Integer level, Integer maxLevel, Class<?> objClass) {         for (Field field : objClass.getDeclaredFields()) {             field.setAccessible(true);             Optional.ofNullable(field.getAnnotation(TransformField.class))                 .ifPresent(transformAnnotation -> {                     String type = transformAnnotation .type();                     Set<Long> transformIds = transformResolverMap.get(type);                     if (transformIds == null) {                         transformIds = new HashSet<>();                         transformResolverMap.put(type, transformIds);                     }                     String sourceFieldName = transformAnnotation .sourceFieldName();                     Object id = this.getFieldValue(obj, objClass, sourceFieldName);                     if(id instanceof Set){                         transformIds.addAll((Set)id);                     }else if(id instanceof List){                         transformIds.addAll((List) id);                     }else if(id != null){                         transformIds.add((Long) id);                     }                 });             Optional.ofNullable(field.getAnnotation(TransformBean.class)).ifPresent(transformBean -> {                 try {                     this.findSourceFieldValues(field.get(obj), transformResolverMap, level + 1, maxLevel);                 } catch (Exception e) {                     log.error("Method:findSourceFieldValues  field name:{} error:{}", field.getName(), e.getMessage());                 }             });         }         Class<?> superclass = objClass.getSuperclass();         if(superclass != null && !superclass.equals(Object.class)){             this.resolverSourceFieldValues(obj, transformResolverMap, level, maxLevel, superclass);         }     }     private Object getFieldValue(Object obj, Class<?> objClass, String fieldName) {         try {             Field sourceField = objClass.getDeclaredField(fieldName);             sourceField.setAccessible(true);             return sourceField.get(obj);         } catch (NoSuchFieldException e) {             Class<?> superclass = objClass.getSuperclass();             if(superclass != null && !superclass.equals(Object.class)){                 return this.getFieldValue(obj, superclass, fieldName);             }             log.error("Method:getFieldValue 1 getDeclaredField fieldName:{} error:{}",                     fieldName, e.getMessage());         } catch (IllegalAccessException e) {             log.error("Method:getFieldValue 2 反射{}值异常 error:{}", fieldName, e.getMessage());         } catch (Exception e) {             log.error("Method:getFieldValue 3 fieldName:{} error:{}", fieldName,                     e.getMessage());         }         return null;     }     /**      * 查询并转换字段      *      * @param obj      *            待转换对象      * @param transformResolverMap      *            存储不同转换类型的源字段值的集合 key为TransformField 注解上type的值 ； value为TransformField注解上sourceFieldName      *            对应的值的集合      * @param type      *            待转换类型      * @param countDownLatch      */     private void findDataAndTransformField(Object obj, Map<String, Set<Long>> transformResolverMap, String type,                                            CountDownLatch countDownLatch, Integer maxLevel) {         Integer level = this.INIT_LEVEL;         FeignRunnable.run(() -> {             try {                 Optional.ofNullable(transformResolverMap.get(type)).ifPresent(ids -> {                     if(CollectionUtils.isEmpty(ids)){                         return;                     }                     TransformResolver transformResolver = (TransformResolver)SpringApplicationHolder.getBean(type);                     log.debug("Method:findDataAndTransformField type:{} transformResolver.execute start ids:{}", type,                         ids);                     Map<Long, Object> resultMap = transformResolver.execute(ids);                     log.debug(                         "Method:findDataAndTransformField type:{} transformResolver.execute end ids:{} resultMap:{}",                         type, ids,                         JSON.toJSONString(resultMap));                     if (resultMap == null || resultMap.isEmpty()) {                         return;                     }                     log.debug("Method:findDataAndTransformField type:{} transformBean start", type);                     transformBean(obj, type, resultMap, level, maxLevel,obj.getClass());                     log.debug("Method:findDataAndTransformField type:{} transformBean end", type);                 });             } catch (Exception e) {                 log.error("Method:findDataAndTransformField type:{}  error:{}", type, e);             } finally {                 countDownLatch.countDown();             }         });     }     /**      * 转换Bean      *      * @param obj      *            待转换对象      * @param type      *            转换类型      * @param resultMap      *            结果集      * @param level      *            级别      */     private void transformBean(Object obj, String type, Map<Long, Object> resultMap, Integer level, Integer maxLevel,Class<?> beanClass) {         if (obj == null) {             return;         }         if (obj instanceof List) {             if (level < maxLevel) {                 Iterator iterator = ((List)obj).iterator();                 while (iterator.hasNext()) {                     Object next = iterator.next();                     this.transformBean(next, type, resultMap, level, maxLevel,next.getClass());                 }             }             return;         }         for (Field field : beanClass.getDeclaredFields()) {             field.setAccessible(true);             Optional.ofNullable(field.getAnnotation(TransformField.class))                 .ifPresent(TransformAnnotation -> {                     String sourceFieldName = TransformAnnotation.sourceFieldName();                     String transformFieldName = TransformAnnotation.transformFieldName();                     try {                         // 待转换字段不为null时，跳过                         if (!type.equals(TransformAnnotation.type()) || field.get(obj) != null) {                             return;                         }                         Field sourceField = beanClass.getDeclaredField(sourceFieldName);                         sourceField.setAccessible(true);                         Object objValue = sourceField.get(obj);                         if(objValue == null){                             return;                         }                         if(sourceField.getType().getName().equals(Set.class.getName())){                             Set<Long> ids = (Set)sourceField.get(obj);                             List list = new ArrayList();                             for (Long id : ids) {                                 Optional.ofNullable(this.getTargetValue(resultMap, id, transformFieldName, sourceFieldName))                                         .ifPresent(value -> list.add(value));                             }                             field.set(obj, list);                         }else if(sourceField.getType().getName().equals(List.class.getName())){                             List<Long> ids = (List)sourceField.get(obj);                             List list = new ArrayList();                             for (Long id : ids) {                                 Optional.ofNullable(this.getTargetValue(resultMap, id, transformFieldName, sourceFieldName))                                         .ifPresent(value -> list.add(value));                             }                             field.set(obj, list);                         }else{                             Long id = (Long)sourceField.get(obj);                             Object value = this.getTargetValue(resultMap, id, transformFieldName, sourceFieldName);                             if(value ==null){                                 return;                             }                             field.set(obj, value);                         }                     }   catch (Exception e) {                         log.error("Method:transformBean 3 sourceFieldName:{} error:{}", sourceFieldName,                             e.getMessage());                     }                 });             Optional.ofNullable(field.getAnnotation(TransformBean.class)).ifPresent(TransformBean -> {                 try {                     Object v = field.get(obj);                     if(v != null){                         this.transformBean(v, type, resultMap, level + 1, maxLevel,v.getClass());                     }                 } catch (IllegalAccessException e) {                     log.error("Method:transformBean  field name:{} error:{}", field.getName(), e.getMessage());                 }             });         }         Class<?> superclass = beanClass.getSuperclass();         if(superclass != null && !superclass.equals(Object.class)){             this.transformBean(obj, type, resultMap, level, maxLevel, superclass);         }     }     /**      * 获取目标属性值      *      * @param resultMap          结果集      * @param id                 数据id      * @param transformFieldName 转换字段      * @param sourceFieldName    待赋值字段      * @return      */     private Object getTargetValue(Map<Long, Object> resultMap, Long id, String transformFieldName, String sourceFieldName) {         Object result = resultMap.get(id);         if (result == null || StringUtils.isBlank(transformFieldName)) {             return result;         }         try {             Field transformField = result.getClass().getDeclaredField(transformFieldName);             transformField.setAccessible(true);             return transformField.get(result);         } catch (NoSuchFieldException e) {             log.error("Method:getTargetValue 1 反射{}值异常 error:{}", sourceFieldName, e.getMessage());         } catch (IllegalAccessException e) {             log.error("Method:getTargetValue 2 sourceFieldName:{} error:{}", sourceFieldName, e.getMessage());         }         return null;     } }

Order-service

order-service 自定义解析器

 

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/**  * 项目解析器  */ @Component public class ProjectTransformResolver implements TransformResolver {     @Autowired     private CustomerServiceApiClient apiClient;     @Override     public Map<Long, Object> execute(Set<Long> ids) {         if (CollectionUtils.isEmpty(ids)) {             return null;         }         List<ProjectBriefDTO> projectBriefDTOList = apiClient.findProjectNameByIds(ids);         if (CollectionUtils.isEmpty(projectBriefDTOList)) {             return null;         }         return projectBriefDTOList.stream().collect(Collectors.toMap(ProjectBriefDTO::getId, a -> a, (k1, k2) -> k1));     } }