Question

我有一个Flink程序，它使用自定义生成器生成数据，同时，我想将该数据保存到SQLite3数据库中。一种方法是在map函数中将数据解析为所需的格式，然后在map操作中插入数据。但我无法做到这一点。我用来向SQLite3写入数据的代码如下所示。我没有提到整个代码，因此数据库连接也存在于代码的初始部分，不包括在下面

 DataStream<Event> merged = stream1.union(stream2,stream3);

    merged.print();


    // sending data to Timekeeper via socket


    merged.map(new MapFunction<Event, String>() {


        @Override
        public String map(Event event) throws Exception {


            String tuple = event.toString();
             Integer patient_id = event.getPatinet_id();
             Integer sensor_id = event.getSensor_id();
             Integer uid = event.getUid();
             Long time = event.getTime();
             Integer value = event.getValue();




                 String sql1 =   "INSERT into mobile_events ( patientid , sensorid , uid , eatg ,valuez ) VALUES (" +
                         + patient_id + ","
                         + sensor_id + ","
                         + uid + ","
                         + time + ","
                         + value
                         + ");" ;


                 stmt.executeUpdate(sql1);

            return tuple + "\n";

        }
    });

问题是

Error:(124, 22) java: local variables referenced from an inner class must be final or effectively final

如果我把它作为最终版，那么我会得到以下错误

Caused by: java.io.NotSerializableException: org.sqlite.jdbc4.JDBC4Statement
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1184)
at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
at org.apache.flink.util.InstantiationUtil.serializeObject(InstantiationUtil.java:315)
at org.apache.flink.api.java.ClosureCleaner.clean(ClosureCleaner.java:81)
... 4 more

无法在Flink的map函数中将数据流写入sqlite3

0 个答案: