Apache Flink: Job throws stack overflow error - apache-flink

Question

I'm trying to execute this simple job in Apache Flink.
public class StreamingJob {
public static void main(String[] args) throws Exception {
final StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
env.setStreamTimeCharacteristic(TimeCharacteristic.EventTime);
Properties inputProperties = new Properties();
ObjectMapper mapper = new ObjectMapper();
DataStream<String> eventStream = env
.addSource(new FileSourceFunction("/path/to/file"));
DataStream<ObjectNode> eventStreamObject = eventStream
.map(x -> mapper.readValue(x, ObjectNode.class));
DataStream<ObjectNode> eventStreamWithTime = eventStreamObject
.assignTimestampsAndWatermarks(new AscendingTimestampExtractor<ObjectNode>() {
#Override
public long extractAscendingTimestamp(ObjectNode element) {
String data = element.get("ts").asText();
if(data.endsWith("Z")) {
data = data.substring(0, data.length() -1);
}
return LocalDateTime.parse(data).toEpochSecond(ZoneOffset.UTC);
}
});
eventStreamObject.print();
env.execute("Local job");
}
}
FileSourceFunction is a custom SourceFunction
public class FileSourceFunction implements SourceFunction<String> {
/**
*
*/
private static final long serialVersionUID = 1L;
private String fileName;
private volatile boolean isRunning = true;
public FileSourceFunction(String fileName) {
this.fileName = fileName;
}
#Override
public void run(SourceContext<String> ctx) throws Exception {
// TODO Auto-generated method stub
try (BufferedReader br = new BufferedReader(new FileReader(fileName))) {
try (Stream<String> stream = br.lines()) {
Iterator<String> it = stream.iterator();
while (isRunning && it.hasNext()) {
synchronized (ctx.getCheckpointLock()) {
ctx.collect(it.next());
}
}
}
}
}
#Override
public void cancel() {
isRunning = false;
}
}
When I run the job it throws an StackOverFlowError. I'm using apache Flink 1.8.1.