for循环优化(6层到2层)

	private List<String> getPackageCode(String dataUcp) throws IOException {
		List<String> packageCode = new ArrayList<>();
		HashMap<String,Object> hashMap = objectMapper.readValue(dataUcp, HashMap.class);
		//遍歷map 2 3 那層
		for (Map.Entry<String, Object> stringObjectEntry : hashMap.entrySet()) {
			//獲取 2 3 那層内部
			HashMap<String,Object> value = (HashMap<String,Object>)stringObjectEntry.getValue();
			//獲取 modelRanges層
			HashMap<String,Object> rangeMaps = (HashMap<String, Object>) value.get("modelRanges");
			//遍歷 modelRanges層 獲取 地盤代號内部數據
			for (Map.Entry<String, Object> objectEntry : rangeMaps.entrySet()) {
				HashMap<String, Object> rangeValueMaps = (HashMap<String, Object>) objectEntry.getValue();
				//獲取models 層數據
				HashMap<String, Object> modelsMaps = (HashMap<String, Object>)rangeValueMaps.get("models");
				for (Map.Entry<String, Object> modelsValue : modelsMaps.entrySet()) {
					HashMap<String, Object> modelsValueMaps = (HashMap<String, Object>) modelsValue.getValue();
					//獲取transmissionVariants數據
					HashMap<String, Object> transmissionMaps = (HashMap<String, Object>) modelsValueMaps.get("transmissionVariants");
					for (Map.Entry<String, Object> transmissionValue : transmissionMaps.entrySet()) {
						HashMap<String, Object> value1 = (HashMap<String, Object>) transmissionValue.getValue();
						HashMap<String, Object> additionalData = (HashMap<String, Object>) value1.get("additionalData");
						for (Map.Entry<String, Object> additional : additionalData.entrySet()) {
							HashMap<String, Object> value2 = (HashMap<String, Object>) additional.getValue();
							HashMap<String, Object> lines = (HashMap<String, Object>) value2.get("lines");
							for (Map.Entry<String, Object> line : lines.entrySet()) {
								HashMap<String, Object> agModelMaps = (HashMap<String, Object>) line.getValue();
								String modelCode = (String) agModelMaps.get("agModelCode");
								packageCode.add(modelCode+"_"+line.getKey());
							}
						}
					}
				}
			}
		}
		return packageCode;
	}

你要说明一下基本情况呀，如表结构之间的关系等；要不然别人都不知道情况怎么帮助你改进呢？

可以给一个具体的数据示例么, 就是之前数据和想要的数据