fix bug

mallinkAdmin/src/main/java/com/iformall/controller/mem/AsyncTask.java

@@ -311,7 +311,9 @@ public class AsyncTask {
                     	String poiId = poiBase.getPoiId();
                     	if (StringUtils.isNotBlank(poiId) && null != poiMerchantIdMap) {
                     		Long merchantId = poiMerchantIdMap.get(poiId);
-                    		poiBase.setMerchantId(String.valueOf(merchantId));
+                    		if (null != merchantId) {
+                    			poiBase.setMerchantId(String.valueOf(merchantId));
+                    		}
                     		if (null != merchantMap && null != merchantId) {
                     			WxMerchant m = merchantMap.get(merchantId);
                     			if (null != m) {