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From Stephan Ewen <se...@apache.org>
Subject Re: java.io.IOException: Couldn't access resultSet
Date Sun, 05 Jun 2016 17:33:21 GMT
Hi David!

You are using the JDBC format that was written for the batch API in the
streaming API.

While that should actually work, it is a somewhat new and less tested
function. Let's double check that the call to open() is properly forwarded.


On Sun, Jun 5, 2016 at 12:47 PM, David Olsen <davidolsen4123@gmail.com>
wrote:

> Switching to use org.apache.flink.api.java.ExecutionEnvironment, my code
> can successfully read data from database through JDBCInputFormat. But I
> need stream mode (and now it seems that the DataSet and DataStream is not
> interchangeable). Are there any additional functions required to be
> executed before StreamExecutionEnvironment creates jdbc input?
>
> Thanks
>
>
> On 5 June 2016 at 18:26, David Olsen <davidolsen4123@gmail.com> wrote:
>
>> I remove the open method when constructing jdbc input format, but I still
>> obtain "couldn't access resultSet" error.
>>
>> Caused by: java.io.IOException: Couldn't access resultSet
>> at
>> org.apache.flink.api.java.io.jdbc.JDBCInputFormat.nextRecord(JDBCInputFormat.java:179)
>> at
>> org.apache.flink.api.java.io.jdbc.JDBCInputFormat.nextRecord(JDBCInputFormat.java:51)
>> at
>> org.apache.flink.streaming.api.functions.source.FileSourceFunction.run(FileSourceFunction.java:124)
>> at
>> org.apache.flink.streaming.api.operators.StreamSource.run(StreamSource.java:78)
>> at
>> org.apache.flink.streaming.runtime.tasks.SourceStreamTask.run(SourceStreamTask.java:56)
>> at
>> org.apache.flink.streaming.runtime.tasks.StreamTask.invoke(StreamTask.java:225)
>> at org.apache.flink.runtime.taskmanager.Task.run(Task.java:559)
>> at java.lang.Thread.run(Thread.java:745)
>> Caused by: java.lang.NullPointerException
>> at
>> org.apache.flink.api.java.io.jdbc.JDBCInputFormat.nextRecord(JDBCInputFormat.java:164)
>> ... 7 more
>>
>> Anything I should check as well?
>>
>> Thanks
>>
>>
>> On 5 June 2016 at 17:26, Chesnay Schepler <chesnay@apache.org> wrote:
>>
>>> you are not supposed to call open yourselves.
>>>
>>>
>>> On 05.06.2016 11:05, David Olsen wrote:
>>>
>>>> Following the sample on the flink website[1] to test jdbc I encountered
>>>> an error "Couldn't access resultSet". It looks like the nextRecord is
>>>> called before open() function. However I've called open() when I construct
>>>> jdbc input format. Any functions I should call before job submission?
>>>>
>>>> def jdbc()= {
>>>>   val jdbcif =
>>>> JDBCInputFormat.buildJDBCInputFormat.setDrivername("com.mysql.jdbc.Driver").setDBUrl("jdbc:mysql://localhost/test").setQuery("select
>>>> name from department").setUsername(...).setPassword(...).finish
>>>>   jdbcif.open(null)
>>>>   jdbcif.asInstanceOf[JDBCInputFormat[Tuple1[String]]]
>>>> }
>>>>
>>>> def main(args: Array[String]) {
>>>>     val env = StreamExecutionEnvironment.getExecutionEnvironment // ->
>>>> import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment
>>>>     val evidence$6 = new TupleTypeInfo(classOf[Tuple1[String]],
>>>> STRING_TYPE_INFO)
>>>>     val stream = env.createInput(jdbc(), evidence$6)
>>>>     stream.map ( new MapFunction[Tuple1[String], String]() {
>>>>       override def map(tuple: Tuple1[String]): String =
>>>> tuple.getField(0)
>>>> }).returns(classOf[String]).writeAsText("/path/to/jdbc")
>>>>     env.execute("test-flink")
>>>> }
>>>>
>>>> The version used in this test is flink 1.0.3 and scala 2.11.
>>>>
>>>> [1].
>>>> https://ci.apache.org/projects/flink/flink-docs-release-1.0/apis/batch/
>>>>
>>>
>>>
>>
>

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