I was using below option
BatchGetItemSpec batchGetItemSpec = new BatchGetItemSpec();
BatchGetItemRequest batchGetItemRequest = new BatchGetItemRequest();
QuerySpec querySpec = new QuerySpec();

        Map<String, KeysAndAttributes> requestItem = new HashMap<>();

        Map<String, AttributeValue> attributeValueMap = new HashMap<>();
         for (GetScoopService.GeneratedKeys key: keys) {
             attributeValueMap.put("pk",new AttributeValue(getPartitionKey(key)));

         }
        requestItem.put(sskTableName,new KeysAndAttributes().withKeys(attributeValueMap));

        batchGetItemRequest.setRequestItems(requestItem);

But here " attributeValueMap.put("pk",new AttributeValue(getPartitionKey(key)));" I m adding this in map so its overriding everything one single item is requested. I need to reqeust a single table against a PK for different PK values in batch query. PLease share some java samples