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 <davidolsen4...@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 <davidolsen4...@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 <ches...@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/ >>>> >>> >>> >> >