内容简介:Java8 Map 示例:一个略复杂的数据映射聚合例子及代码重构
本文内容来自真实的工作案例,因其转换略复杂,且有一定意义,故记录之。
问题
给定一个JSON串
{ "item:s_id:18006666": "1024", "item:s_id:18008888": "1024", "item:g_id:18006666": "6666", "item:g_id:18008888": "8888", "item:num:18008888": "8", "item:num:18006666": "6", "item:item_core_id:18006666": "9876666", "item:item_core_id:18008888": "9878888", "item:order_no:18006666": "E20171013174712025", "item:order_no:18008888": "E20171013174712025", "item:id:18008888": "18008888", "item:id:18006666": "18006666", "item_core:num:9878888": "8", "item_core:num:9876666": "6", "item_core:id:9876666": "9876666", "item_core:id:9878888": "9878888", "item_price:item_id:1000": "9876666", "item_price:item_id:2000": "9878888", "item_price:price:1000": "100", "item_price:price:2000": "200", "item_price:id:2000": "2000", "item_price:id:1000": "1000", "item_price_change_log:id:1111": "1111", "item_price_change_log:id:2222": "2222", "item_price_change_log:item_id:1111": "9876666", "item_price_change_log:item_id:2222": "9878888", "item_price_change_log:detail:1111": "haha1111", "item_price_change_log:detail:2222": "haha2222", "item_price_change_log:id:3333": "3333", "item_price_change_log:id:4444": "4444", "item_price_change_log:item_id:3333": "9876666", "item_price_change_log:item_id:4444": "9878888", "item_price_change_log:detail:3333": "haha3333", "item_price_change_log:detail:4444": "haha4444" }
这是一个订单的两个商品的基本信息、价格信息以及计价变更信息,是从DB里的结构获取到的记录。为了企业保密性,对表、字段以及值做了简化的特殊处理。目标是将这个订单的各个商品的信息聚合在一起。 即得到:
{1024_E20171013174712025_18006666={item:id=18006666, item_price:price=100, item_price:id=1000, item_price_change_log:id=[3333, 1111], item_core:num=6, item:g_id=6666, item:item_core_id=9876666, item_price:item_id=9876666, item:order_no=E20171013174712025, item_core:id=9876666, item_price_change_log:item_id=[9876666, 9876666], item:s_id=1024, item:num=6, item_price_change_log:detail=[haha3333, haha1111]}, 1024_E20171013174712025_18008888={item:id=18008888, item_price:price=200, item_price:id=2000, item_price_change_log:id=[2222, 4444], item_core:num=8, item:g_id=8888, item:item_core_id=9878888, item_price:item_id=9878888, item:order_no=E20171013174712025, item_price_change_log:item_id=[9878888, 9878888], item:s_id=1024, item_core:id=9878888, item:num=8, item_price_change_log:detail=[haha2222, haha4444]}}
细心的读者会发现,一个商品 item 对应一个 item_core, 一个 item_price ,可能对应多个 item_price_change_log 。这三个表都是通过 item:item_core_id 来关联的,在 item 表是 item:item_core_id 字段, 在 item_price 表是 item_price:item_id 字段, 在 item_price_change_log 表是 item_price_change_log:item_id 字段。
提示
基本思路是:
STEP1: 对于含有表 item, item_core, item_price, item_price_change_log 数据的指定JSON,构建一个总的 itemIndexMap[table:id, Map[table:field, value]],其中 key 是 table:id, value 是一个 valMap, valMap 的键是 table:field, 值是对应的最后面的值。 table: 作为名字空间的前缀,是为了避免不同表之间的ID和field相互重合覆盖。 见方法 buildItemIndexMap 的实现。
STEP2: 从 itemIndexMap 构建 item:id 与 item:item_core_id 的映射 itemCoreId2originItemIdMap;在实际应用中, originItemId 为 oldItemId (item:id), itemCoreId 为 newItemId (item:item_core_id);
STEP3: 对于每一个 [table:id, Map[table:field, value]], 通过 itemCoreId2originItemIdMap 拿到对应的 originitemId , 然后使用 originitemId 为键替换itemIndexMap中对应的 item_core:id, item_price:id, item_price_change_log:id,将具有相同的 originItemId 的不同的 Map[table:field, value] 进行合并后,添加到新的newItemIndexMap 中。
程序实现
初步实现
ItemUtil.java
package zzz.study.utils; /** * Created by shuqin on 17/11/10. */ import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.util.HashMap; import java.util.Map; import java.util.Set; import static zzz.study.utils.NewMapUtil.merge; /** * Created by shuqin on 17/10/23. */ public class ItemUtil { private static Logger logger = LoggerFactory.getLogger(ItemUtil.class); /** * 构建一个订单的所有商品级别的信息以及映射 * @param multiItemInfoMapForOneOrder 一个订单下多个商品的信息 * @return 一个订单的所有商品级别的信息以及映射 * * key 是 sID + order_no + item_id ; item_id 对应 item.id, 对应 item_core.item_core_id */ public static Map<String, Map<String,Object>> buildFinalOrderItemMap(Map<String,String> multiItemInfoMapForOneOrder) { try { return mergeOrderItemMap(buildItemIndexMap(multiItemInfoMapForOneOrder)); } catch (Exception ex) { logger.error("failed to buildFinalOrderItemMap for: " + multiItemInfoMapForOneOrder, ex); return new HashMap<>(); } } /** * 构建一个订单的所有商品级别的信息以及映射 * @param itemInfoMap 商品级别的信息 * @return 一个订单的所有商品的信息 * * NOTE: itemInfoMap 是对应一个订单的所有商品的信息的映射,不要传多个订单的信息进来,可能重复 * * key = table:table_unique_id , value = map [ table:field, value ] * * eg. map [ item:goods_type:1800888 = 0 , item:num:1800888 = 8 ] * will be transformed into map[item:1800888 = map[item:goods_type=0 , item:num=8]] */ public static Map<String,Map<String,String>> buildItemIndexMap(Map<String, String> itemInfoMap) { Map<String, Map<String,String>> itemIndexMap = new HashMap<>(); itemInfoMap.forEach( (key, value) -> { String[] keyparts = key.split(":"); // 只考虑三段式 tablename:field:id if (keyparts != null && keyparts.length == 3) { String table = keyparts[0]; String field = keyparts[1]; String index = keyparts[2]; String indexKey = table+ ":" + index; String fieldKey = table+":"+field; if (itemIndexMap.get(indexKey) == null) { itemIndexMap.put(indexKey, new HashMap<>()); } itemIndexMap.get(indexKey).put(fieldKey, String.valueOf(value)); } } ); return itemIndexMap; } /** * 聚合一个订单下的所有商品信息 * @param itemIndexMap 一个订单所有商品的信息映射 * @return 一个订单下的所有商品信息 * * key 是 sID + order_no + item_id ; item_id 对应 item.id, item_core.item_core_id */ private static Map<String, Map<String,Object>> mergeOrderItemMap(Map<String, Map<String,String>> itemIndexMap) { if (itemIndexMap == null || itemIndexMap.isEmpty()) { return new HashMap<>(); } // Map[oldItemId, newItemId] Map<String,String> old2newItemIdMap = new HashMap<>(); Map<String,String> new2oldItemIdMap = new HashMap<>(); Set<Map.Entry<String,Map<String,String>>> entries = itemIndexMap.entrySet(); String orderNo = ""; String sID = ""; for (Map.Entry<String,Map<String,String>> entry: entries) { String indexKey = entry.getKey(); Map<String,String> value = entry.getValue(); if (indexKey.startsWith("item:")) { old2newItemIdMap.put(indexKey, value.get("item:item_core_id")); new2oldItemIdMap.put(value.get("item:item_core_id"), indexKey); orderNo = value.get("item:order_no"); sID = value.get("item:s_id"); } } Map<String, Map<String,Object>> newItemIndexMap = new HashMap<>(); for (Map.Entry<String,Map<String,String>> entry: entries) { String indexKey = entry.getKey(); Map<String,String> value = entry.getValue(); if (indexKey.startsWith("item:")) { if (newItemIndexMap.get(indexKey) == null) { newItemIndexMap.put(indexKey, new HashMap<>()); } newItemIndexMap.get(indexKey).putAll(value); } else if (indexKey.startsWith("item_core:")) { String itemCoreId = indexKey.split(":")[1]; String oldItemId = new2oldItemIdMap.get(itemCoreId); if (newItemIndexMap.get(oldItemId) == null) { newItemIndexMap.put(oldItemId, new HashMap<>()); } newItemIndexMap.get(oldItemId).putAll(value); } else if (indexKey.startsWith("item_price:")) { // item_price 与 item_id 一对一关系 String itemCoreId = itemIndexMap.get(indexKey).get("item_price:item_id"); String oldItemId = new2oldItemIdMap.get(itemCoreId); if (newItemIndexMap.get(oldItemId) == null) { newItemIndexMap.put(oldItemId, new HashMap<>()); } newItemIndexMap.get(oldItemId).putAll(value); } else if (indexKey.startsWith("item_price_change_log:")) { // item_price_change_log 与 item_id 多对一关系 String itemCoreId = itemIndexMap.get(indexKey).get("item_price_change_log:item_id"); String oldItemId = new2oldItemIdMap.get(itemCoreId); if (newItemIndexMap.get(oldItemId) == null) { newItemIndexMap.put(oldItemId, new HashMap<>()); } Map<String,Object> srcMap = newItemIndexMap.get(oldItemId); newItemIndexMap.get(oldItemId).putAll(merge(srcMap, value)); } } return buildFinalOrderItemMap(newItemIndexMap, old2newItemIdMap, orderNo, sID); } /** * 构建最终的订单商品信息 * @param itemIndexMap 商品信息 * @param old2newItemIdMap 新老itemId映射 * @param orderNo 订单号 * @param sID 店铺号 * @return 订单商品扩展信息 */ private static Map<String, Map<String,Object>> buildFinalOrderItemMap(Map<String, Map<String,Object>> itemIndexMap, Map<String,String> old2newItemIdMap, String orderNo, String sID) { Map<String, Map<String,Object>> finalResult = new HashMap<>(); Set<Map.Entry<String,Map<String,Object>>> entries = itemIndexMap.entrySet(); for (Map.Entry<String,Map<String,Object>> entry: entries) { String indexKey = entry.getKey(); Map<String,Object> value = entry.getValue(); String itemId = indexKey.split(":")[1]; String itemKey = sID + "_" + orderNo + "_" + itemId; finalResult.put(itemKey, value); } return finalResult; } }
NewMapUtil.java
package zzz.study.utils; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; /** * Created by shuqin on 17/11/10. */ public class NewMapUtil { /** * 将 map 的值转为字符串类型 */ public static Map<String,String> transMap(Map<String,Object> map) { if (map == null) { return null; } Map<String,String> result = new HashMap<>(); map.forEach( (k,v) -> result.put(k, v != null ? v.toString(): null) ); return result; } /** * 将两个 Map 里相同 key 的值合并为列表 * * eg. src = ["id": 1, "detail": "haha111", "extra":"extra111"] , * dest = ["id": 2, "detail": "haha222", "another": "another222"] * merge 之后返回 ["id": [1,2], "detail": ["haha111", "haha222"], "extra":"extra111", "another": "another222"] ` */ public static Map<String, ? extends Object> merge(Map<String,? extends Object> src, Map<String, ? extends Object> dest) { if (src == null || src.size() == 0) { return dest; } if (dest == null || dest.size() == 0) { return src; } Map<String, Object> result = new HashMap<>(); src.forEach( (key, value) -> { Object valueDesc = dest.get(key); if (valueDesc != null) { result.put(key, mergeToList(value, valueDesc)); } else { result.put(key, value); } } ); dest.forEach( (key, value) -> { if (result.get(key) == null) { result.put(key, value); } } ); return result; } public static List mergeToList(Object src, Object... args) { List valList = new ArrayList(); add(valList, src); for (Object arg: args) { add(valList, arg); } return valList; } public static List add(List valList, Object src) { if (src == null) { return valList; } if (src instanceof List) { valList.addAll((List)src); } else { valList.add(src); } return valList; } }
代码 重构
可以看到,初步实现虽然实现了功能,可是代码比较乱,尤其是 mergeOrderItemMap 方法,混杂了业务表的逻辑,理解和扩展起来比较麻烦。需要仔细重构下。另外,Map的遍历访问比较啰嗦,可以更简洁一些。
使用forEach进行Map遍历
重构从简单做起。原来使用了
Set<Map.Entry<String,Map<String,Object>>> entries = itemIndexMap.entrySet(); for (Map.Entry<String,Map<String,Object>> entry: entries) { String indexKey = entry.getKey(); Map<String,Object> value = entry.getValue(); String itemId = indexKey.split(":")[1]; String itemKey = sID + "_" + orderNo + "_" + itemId; finalResult.put(itemKey, value); }
在 java 8 中可使用 forEach 语法简洁表达:
itemIndexMap.forEach( (indexKey,value) -> { String itemId = indexKey.split(":")[1]; String itemKey = sID + "_" + orderNo + "_" + itemId; finalResult.put(itemKey, value); } );
抽离通用逻辑
里面有很多如下重复代码
if (newItemIndexMap.get(oldItemId) == null) { newItemIndexMap.put(oldItemId, new HashMap<>()); } newItemIndexMap.get(oldItemId).putAll(value);
实际上就是将新的item_core_id 映射成 item.id ,然后填充到新的Map,可以抽离出一个函数,然后复用。
private static void putNewIndexMap(Map<String, Map<String,Object>> newItemIndexMap, String indexKey, Map<String,String> value, Function<String, String> getOriginItemIdFunc) { String originItemId = getOriginItemIdFunc.apply(indexKey); if (newItemIndexMap.get(originItemId) == null) { newItemIndexMap.put(originItemId, new HashMap<>()); } Map<String,Object> srcMap = newItemIndexMap.get(originItemId); newItemIndexMap.get(originItemId).putAll(merge(srcMap, value)); } 调用: putNewIndexMap(newItemIndexMap, indexKey, value, key -> key);
配置化
看如下代码,里面含有 item_price: , item_price:item_id 这样的业务信息,破坏了方法的通用性。
if (indexKey.startsWith("item_price:")) { // item_price 与 item_id 一对一关系 String itemCoreId = itemIndexMap.get(indexKey).get("item_price:item_id"); }
可以抽离出来做成配置。好的配置可以让代码大大简化。仔细思考下整个过程:当 indexKey 包含某个表的前缀时,取它对应的 itemCoreId 的字段,然后得到 itemCoreId ,再根据 putNewIndexMap 方法将对应的 Map 添加到最终的Map中。见如下代码:
private static Map<String,String> itemIdConf = new HashMap() { { put("item", "item:item_core_id"); put("item_core", "item_core:id"); put("item_price", "item_price:item_id"); put("item_price_change_log", "item_price_change_log:item_id"); } }; String table = indexKey.split(":")[0]; if (itemIdConf.containsKey(table)) { String itemCoreIdField = itemIdConf.get(table); String itemCoreId = itemIndexMap.get(indexKey).get(itemCoreIdField); putNewIndexMap(newItemIndexMap, indexKey, value, key -> new2oldItemIdMap.get(itemCoreId)); }
哈!if-elseif-elseif 语句消失了!此时,才说真正抓住了设计重点:将itemId 的映射抽离出来做成配置,然后其它的依此解析。
重构后的ItemUtil
// 这个配置含有新老itemId映射的信息以及获取orderNo, sID 的字段信息 private static List<String> itemBaseDataConf = Arrays.asList("item:", "item:item_core_id", "item:order_no", "item:s_id"); private static Map<String,String> itemIdConf = new HashMap() { { put("item", "item:item_core_id"); put("item_core", "item_core:id"); put("item_price", "item_price:item_id"); put("item_price_change_log", "item_price_change_log:item_id"); } }; /** * 聚合一个订单下的所有商品信息 * @param itemIndexMap 一个订单所有商品的信息映射 * @return 一个订单下的所有商品信息 * * key 是 sID + order_no + item_id ; */ private static Map<String, Map<String,Object>> mergeOrderItemMap(Map<String, Map<String,String>> itemIndexMap) { if (itemIndexMap == null || itemIndexMap.isEmpty()) { return new HashMap<>(); } // Map[oldItemId, newItemId] Map<String,String> old2newItemIdMap = new HashMap<>(); Map<String,String> new2oldItemIdMap = new HashMap<>(); Set<Map.Entry<String,Map<String,String>>> entries = itemIndexMap.entrySet(); String orderNo = ""; String kdtId = ""; // 构建itemID映射 for (Map.Entry<String,Map<String,String>> entry: entries) { String indexKey = entry.getKey(); Map<String,String> value = entry.getValue(); if (indexKey.startsWith(itemBaseDataConf.get(0))) { old2newItemIdMap.put(indexKey, value.get(itemBaseDataConf.get(1))); new2oldItemIdMap.put(value.get(itemBaseDataConf.get(1)), indexKey); orderNo = value.get(itemBaseDataConf.get(2)); kdtId = value.get(itemBaseDataConf.get(3)); } } Map<String, Map<String,Object>> newItemIndexMap = aggregationAllInfoOfEachItem(itemIndexMap, new2oldItemIdMap); return buildFinalOrderItemMap(newItemIndexMap, old2newItemIdMap, orderNo, kdtId); } /* * 聚合每个商品的所有信息 * * Map[item:id, Map[table:field, value]] */ private static Map<String, Map<String,Object>> aggregationAllInfoOfEachItem(Map<String, Map<String,String>> itemIndexMap, Map<String,String> new2oldItemIdMap) { Map<String, Map<String,Object>> newItemIndexMap = new HashMap<>(); itemIndexMap.forEach( (indexKey, value) -> { String table = indexKey.split(":")[0]; if (itemIdConf.containsKey(table)) { String itemCoreIdField = itemIdConf.get(table); String itemCoreId = itemIndexMap.get(indexKey).get(itemCoreIdField); putNewIndexMap(newItemIndexMap, indexKey, value, key -> new2oldItemIdMap.get(itemCoreId)); } } ); return newItemIndexMap; } /* * 将各商品信息聚合到相应的原itemId的键下 */ private static void putNewIndexMap(Map<String, Map<String,Object>> newItemIndexMap, String indexKey, Map<String,String> value, Function<String, String> getOriginItemIdFunc) { String originItemId = getOriginItemIdFunc.apply(indexKey); if (newItemIndexMap.get(originItemId) == null) { newItemIndexMap.put(originItemId, new HashMap<>()); } Map<String,Object> srcMap = newItemIndexMap.get(originItemId); newItemI
Java8特性
Function
可以看到,putNewIndexMap 使用了 Function 作为参数,让调用方指定如何去获取 originItemId,然后根据获取的originItemId进行通用处理。这里 Function 实现了模板方法模式。
协变
注意到这个方法签名使用了 [ ? extends Object ]。 这里使用了协变特性。即对应参数 Map[String, ? extend Object],既可以传入 Map[String, Object], 也可以传入 Map[String, String] ,或 Map[String, Entity] ,避免从 Map[String, Entity] 到 Map[String, Object] 的无聊转换。
public static Map<String, ? extends Object> merge(Map<String,? extends Object> src, Map<String, ? extends Object> dest)
单测
ItemUtilTest.java
package cc.lovesq.study.test.datastructure; import org.junit.Test; import java.util.Arrays; import java.util.Map; import cc.lovesq.study.test.CommonForTest; import zzz.study.utils.ItemUtil; import zzz.study.utils.JsonUtil; import zzz.study.utils.NewMapUtil; /** * Created by shuqin on 17/11/10. */ public class ItemUtilTest extends CommonForTest { String newItemInfoStr = "{\n" + " \"item:s_id:18006666\": \"1024\",\n" + " \"item:s_id:18008888\": \"1024\",\n" + " \"item:g_id:18006666\": \"6666\",\n" + " \"item:g_id:18008888\": \"8888\",\n" + " \"item:num:18008888\": \"8\",\n" + " \"item:num:18006666\": \"6\",\n" + " \"item:item_core_id:18006666\": \"9876666\",\n" + " \"item:item_core_id:18008888\": \"9878888\",\n" + " \"item:order_no:18006666\": \"E20171013174712025\",\n" + " \"item:order_no:18008888\": \"E20171013174712025\",\n" + " \"item:id:18008888\": \"18008888\",\n" + " \"item:id:18006666\": \"18006666\",\n" + " \"item_core:num:9878888\": \"8\",\n" + " \"item_core:num:9876666\": \"6\",\n" + " \"item_core:id:9876666\": \"9876666\",\n" + " \"item_core:id:9878888\": \"9878888\",\n" + " \"item_price:item_id:1000\": \"9876666\",\n" + " \"item_price:item_id:2000\": \"9878888\",\n" + " \"item_price:price:1000\": \"100\",\n" + " \"item_price:price:2000\": \"200\",\n" + " \"item_price:id:2000\": \"2000\",\n" + " \"item_price:id:1000\": \"1000\",\n" + " \"item_price_change_log:id:1111\": \"1111\",\n" + " \"item_price_change_log:id:2222\": \"2222\",\n" + " \"item_price_change_log:item_id:1111\": \"9876666\",\n" + " \"item_price_change_log:item_id:2222\": \"9878888\",\n" + " \"item_price_change_log:detail:1111\": \"haha1111\",\n" + " \"item_price_change_log:detail:2222\": \"haha2222\",\n" + " \"item_price_change_log:id:3333\": \"3333\",\n" + " \"item_price_change_log:id:4444\": \"4444\",\n" + " \"item_price_change_log:item_id:3333\": \"9876666\",\n" + " \"item_price_change_log:item_id:4444\": \"9878888\",\n" + " \"item_price_change_log:detail:3333\": \"haha3333\",\n" + " \"item_price_change_log:detail:4444\": \"haha4444\"\n" + "}"; @Test public void testBuildItemIndexMapForNew() { Map<String,Object> itemInfoMap = JsonUtil.readMap(newItemInfoStr); Map<String,Map<String,String>> itemIndexMap = ItemUtil .buildItemIndexMap(NewMapUtil.transMap(itemInfoMap)); System.out.println(itemIndexMap); eq("18006666", itemIndexMap.get("item:18006666").get("item:id")); eq("6666", itemIndexMap.get("item:18006666").get("item:g_id")); eq("1024", itemIndexMap.get("item:18006666").get("item:s_id")); eq("E20171013174712025", itemIndexMap.get("item:18006666").get("item:order_no")); eq("9876666", itemIndexMap.get("item:18006666").get("item:item_core_id")); eq("18008888", itemIndexMap.get("item:18008888").get("item:id")); eq("8888", itemIndexMap.get("item:18008888").get("item:g_id")); eq("1024", itemIndexMap.get("item:18008888").get("item:s_id")); eq("E20171013174712025", itemIndexMap.get("item:18008888").get("item:order_no")); eq("9878888", itemIndexMap.get("item:18008888").get("item:item_core_id")); eq("9876666", itemIndexMap.get("item_core:9876666").get("item_core:id")); eq("6", itemIndexMap.get("item_core:9876666").get("item_core:num")); eq("9878888", itemIndexMap.get("item_core:9878888").get("item_core:id")); eq("8", itemIndexMap.get("item_core:9878888").get("item_core:num")); eq("9876666", itemIndexMap.get("item_price:1000").get("item_price:item_id")); eq("1000", itemIndexMap.get("item_price:1000").get("item_price:id")); eq("100", itemIndexMap.get("item_price:1000").get("item_price:price")); eq("9878888", itemIndexMap.get("item_price:2000").get("item_price:item_id")); eq("2000", itemIndexMap.get("item_price:2000").get("item_price:id")); eq("200", itemIndexMap.get("item_price:2000").get("item_price:price")); eq("9876666", itemIndexMap.get("item_price_change_log:1111").get("item_price_change_log:item_id")); eq("haha1111", itemIndexMap.get("item_price_change_log:1111").get("item_price_change_log:detail")); eq("9878888", itemIndexMap.get("item_price_change_log:2222").get("item_price_change_log:item_id")); eq("haha2222", itemIndexMap.get("item_price_change_log:2222").get("item_price_change_log:detail")); eq("9876666", itemIndexMap.get("item_price_change_log:3333").get("item_price_change_log:item_id")); eq("haha3333", itemIndexMap.get("item_price_change_log:3333").get("item_price_change_log:detail")); eq("9878888", itemIndexMap.get("item_price_change_log:4444").get("item_price_change_log:item_id")); eq("haha4444", itemIndexMap.get("item_price_change_log:4444").get("item_price_change_log:detail")); } @Test public void testBuildFinalOrderItemMapForNew() { Map<String,Object> itemInfoMap = JsonUtil.readMap(newItemInfoStr); Map<String, Map<String,Object>> finalOrderItemMap = ItemUtil .buildFinalOrderItemMap(NewMapUtil.transMap(itemInfoMap)); System.out.println(finalOrderItemMap); eq("18006666", finalOrderItemMap.get("1024_E20171013174712025_18006666").get("item:id")); eq("6666", finalOrderItemMap.get("1024_E20171013174712025_18006666").get("item:g_id")); eq("1024", finalOrderItemMap.get("1024_E20171013174712025_18006666").get("item:s_id")); eq("E20171013174712025", finalOrderItemMap.get("1024_E20171013174712025_18006666").get("item:order_no")); eq("9876666", finalOrderItemMap.get("1024_E20171013174712025_18006666").get("item_core:id")); eq("6", finalOrderItemMap.get("1024_E20171013174712025_18006666").get("item_core:num")); eq("9876666", finalOrderItemMap.get("1024_E20171013174712025_18006666").get("item_price:item_id")); eq("100", finalOrderItemMap.get("1024_E20171013174712025_18006666").get("item_price:price")); eq("18008888", finalOrderItemMap.get("1024_E20171013174712025_18008888").get("item:id")); eq("8888", finalOrderItemMap.get("1024_E20171013174712025_18008888").get("item:g_id")); eq("1024", finalOrderItemMap.get("1024_E20171013174712025_18008888").get("item:s_id")); eq("E20171013174712025", finalOrderItemMap.get("1024_E20171013174712025_18008888").get("item:order_no")); eq("9878888", finalOrderItemMap.get("1024_E20171013174712025_18008888").get("item_core:id")); eq("8", finalOrderItemMap.get("1024_E20171013174712025_18008888").get("item_core:num")); eq("9878888", finalOrderItemMap.get("1024_E20171013174712025_18008888").get("item_price:item_id")); eq("200", finalOrderItemMap.get("1024_E20171013174712025_18008888").get("item_price:price")); eq(Arrays.asList("haha3333", "haha1111"), finalOrderItemMap.get("1024_E20171013174712025_18006666").get("item_price_change_log:detail")); eq(Arrays.asList("haha2222", "haha4444"), finalOrderItemMap.get("1024_E20171013174712025_18008888").get("item_price_change_log:detail")); } }
CommonForTest.java
package cc.lovesq.study.test; import org.junit.Assert; import java.util.List; import static org.junit.Assert.assertEquals; /** * Created by shuqin on 17/11/10. */ public class CommonForTest { public static final String NOT_THROW_EXCEPTION = "Not Throw Exception"; public void eq(Object expected, Object actual) { assertEquals(expected, actual); } public <T> void eq(T[] expected, T[] actual) { Assert.assertArrayEquals(expected, actual); } public <T> void eq(List<T> expectedList, List<T> actualList) { if (expectedList == null && actualList == null) { return ; } assertEquals(expectedList.size(), actualList.size()); for (int i=0; i< expectedList.size(); i++) { assertEquals(expectedList.get(i), actualList.get(i)); } } public void fail(String message) { Assert.fail(message); } }
package zzz.study.utils; import org.codehaus.jackson.map.DeserializationConfig; import org.codehaus.jackson.map.ObjectMapper; import org.codehaus.jackson.map.annotate.JsonSerialize; import java.text.SimpleDateFormat; import java.util.HashMap; import java.util.Map; public class JsonUtil { private static final ObjectMapper MAPPER = new ObjectMapper(); static { // 为保持对象版本兼容性,忽略未知的属性 MAPPER.configure(DeserializationConfig.Feature.FAIL_ON_UNKNOWN_PROPERTIES, false); // 序列化的时候,跳过null值 MAPPER.getSerializationConfig().setSerializationInclusion(JsonSerialize.Inclusion.NON_NULL); // date类型转化 SimpleDateFormat fmt = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); MAPPER.setDateFormat(fmt); } /** * 将一个json字符串解码为java对象 * * 注意:如果传入的字符串为null,那么返回的对象也为null * * @param json json字符串 * @param cls 对象类型 * @return 解析后的java对象 * @throws RuntimeException 若解析json过程中发生了异常 */ public static <T> T toObject(String json, Class<T> cls) { if (json == null) { return null; } try { return MAPPER.readValue(json, cls); } catch (Exception e) { return null; } } /** * 读取JSON字符串为MAP */ @SuppressWarnings("unchecked") public static Map<String, Object> readMap(String json) { return toObject(json, HashMap.class); } }
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Convergence Culture
Henry Jenkins / NYU Press / 2006-08-01 / USD 30.00
"Convergence Culture" maps a new territory: where old and new media intersect, where grassroots and corporate media collide, where the power of the media producer, and the power of the consumer intera......一起来看看 《Convergence Culture》 这本书的介绍吧!