如何使用Java MongoClient连接mongodb地图集？

Question

  

在等待匹配服务器的30000毫秒后超时   ReadPreferenceServerSelector {readPreference = nearest}。客户观点   群集状态为{type = UNKNOWN，服务器= [{address =：27017，   类型=未知，状态=正在连接，   exception = {com.mongodb.MongoSocketReadException：已过早到达   流的结尾}}，{地址=：27017，类型=未知，   状态=正在连接，异常= {com.mongodb.MongoSocketReadException：   过早到达流的末尾}}

尝试将MongoDB地图集与Java MongoClient连接时出现此错误

ServerAddress primaryServer = new ServerAddress(<primary_host>,
                Integer.parseInt(27017));

ServerAddress secondaryServer = new ServerAddress(<secondary_host>,
                Integer.parseInt(27017));

MongoCredential mongoCred = MongoCredential.createScramSha1Credential(<user_name>, <db_name>, <password>.toCharArray());

MongoClientOptions.Builder mongoConf = new MongoClientOptions.Builder();
mongoConf.readPreference(ReadPreference.nearest());

MongoClient mongoClient = new MongoClient(Arrays.asList(primaryServer, secondaryServer), Arrays.asList(mongoCred, mongoCred), mongoConf.build());