reduce precision when the result of goods is empty

src/main/java/com/uas/search/service/impl/SearchServiceImpl.java

@@ -809,10 +809,10 @@ public class SearchServiceImpl implements SearchService {
 		// 先根据品牌搜索，品牌不存在再搜索型号等
 		keywordFields.add(SearchConstants.GOODS_BR_NAME_CN_UNTOKENIZED_FIELD);
 		keywordFields.add(SearchConstants.GOODS_BR_NAME_EN_UNTOKENIZED_FIELD);
-		Map<String, Object> goodsIds = getGoodsIds(keyword, keywordFields, false, pageParams);
+		Map<String, Object> goodsIds = getGoodsIds(keyword, keywordFields, false, pageParams, false);
 		if (CollectionUtils.isEmpty(goodsIds) || goodsIds.get("componentIds") == null
 				|| JSONObject.parseArray(goodsIds.get("componentIds").toString()).isEmpty()) {
-			goodsIds = getGoodsIds(keyword, null, true, pageParams);
+			goodsIds = getGoodsIds(keyword, null, true, pageParams, true);
 		}
 		return goodsIds;
 	}
@@ -824,11 +824,12 @@ public class SearchServiceImpl implements SearchService {
 	 * @param tokenized
 	 *            是否分词
 	 * @param pageParams
+	 * @param recursivelyGet 是否递归获取（逐步降低精度，直到只匹配一个字符）
 	 * @return
 	 * @throws SearchException
 	 */
 	private Map<String, Object> getGoodsIds(String keyword, List<String> keywordFields, Boolean tokenized,
-			PageParams pageParams) throws SearchException {
+			PageParams pageParams, Boolean recursivelyGet) throws SearchException {
 		// 因为器件、属性值的数据量远比类目、品牌大得多，而且器件搜索可能还需进行分页，
 		// 所以涉及器件、属性值的搜索，大都不能像类目和品牌一样直接利用SearchUtils.getDocuments方法
 		IndexSearcher indexSearcher = SearchUtils.getIndexSearcher(SearchConstants.GOODS_TABLE_NAME);
@@ -961,6 +962,10 @@ public class SearchServiceImpl implements SearchService {
 				hits = indexSearcher.search(booleanQuery, pageParams.getSize(), sort, true, false);
 			}
 
+			// 如果没有结果，则降低精度，直至 keyword 长度为 1
+			if(recursivelyGet && hits.totalHits < 1 && !SearchUtils.isKeywordInvalid(keyword) && keyword.length() > 1){
+				return getGoodsIds(keyword.substring(0, keyword.length() - 1), keywordFields, tokenized, pageParams, recursivelyGet);
+			}
 			ScoreDoc[] scoreDocs = hits.scoreDocs;
 			for (ScoreDoc scoreDoc : scoreDocs) {
 				// 数据量太大，需要指定将获取的数据（以免载入不必要的数据，降低速度）
@@ -997,9 +1002,9 @@ public class SearchServiceImpl implements SearchService {
 		// 先根据品牌搜索，品牌不存在再搜索型号等
 		keywordFields.add(SearchConstants.GOODS_BR_NAME_CN_UNTOKENIZED_FIELD);
 		keywordFields.add(SearchConstants.GOODS_BR_NAME_EN_UNTOKENIZED_FIELD);
-		List<Map<String, Object>> result = collectBySearchGoods(keyword, keywordFields, false, collectedField, filters);
+		List<Map<String, Object>> result = collectBySearchGoods(keyword, keywordFields, false, collectedField, filters, false);
 		if (CollectionUtils.isEmpty(result)) {
-			result = collectBySearchGoods(keyword, null, true, collectedField, filters);
+			result = collectBySearchGoods(keyword, null, true, collectedField, filters, true);
 		}
 		return result;
 
@@ -1013,13 +1018,23 @@ public class SearchServiceImpl implements SearchService {
 	 *            是否分词
 	 * @param collectedField
 	 * @param filters
+	 * @param recursivelyGet 是否递归获取（逐步降低精度，直到只匹配一个字符）
 	 * @return
 	 */
 	private List<Map<String, Object>> collectBySearchGoods(String keyword, List<String> keywordFields,
-			Boolean tokenized, CollectField collectedField, Map<FilterField, Object> filters) {
+			Boolean tokenized, CollectField collectedField, Map<FilterField, Object> filters, Boolean recursivelyGet) {
 		if (collectedField == null && CollectionUtils.isEmpty(filters)) {
 			throw new SearchException("参数不合法：collectedField=" + collectedField + ", filter=" + filters);
 		}
+		// 与批次搜索的搜索词保持一致，最终有结果的 keyword 是相同的
+		if(recursivelyGet != null && recursivelyGet){
+			PageParams pageParams = new PageParams();
+			pageParams.setFilters(filters);
+			Map<String, Object> goodsIds = getGoodsIds(keyword, keywordFields, tokenized, pageParams, false);
+			if(Integer.parseInt(goodsIds.get("total").toString()) <1){
+				return collectBySearchGoods(keyword.substring(0, keyword.length() - 1), keywordFields, tokenized, collectedField, filters, true);
+			}
+		}
 		IndexSearcher indexSearcher = SearchUtils.getIndexSearcher(SearchConstants.GOODS_TABLE_NAME);
 
 		List<Map<String, Object>> result = new ArrayList<>();