Using static variables inside Cascading

Question

When I start my MapReduce job I save the current timestamp as a Date object in a static variable of my main class.

Later when I want to read the value from a different class (such as my custom Cascading Filter or Cascading Function class) the job crashes with a java.lang.NullPointerException according to Driven.

Is it not possible to access a static variable within the Cascading logic? I have no idea why this doesn't work. The Date variable is definitely not null as I print it to console when the job is launched and afterwards it is not touched by any logic.

This is the class that throws the error. If I create a new Date (with the current time) within the operate() method everything works fine.

public class TimestampAppender extends BaseOperation implements Function {

public TimestampAppender(Fields fieldDeclaration) {
    super(Fields.ARGS);
}

public void operate(FlowProcess flowProcess, FunctionCall functionCall) {

    TupleEntry argument = functionCall.getArguments();

    Date timestamp = Main.timeFrameMiddle;
    String arg0 = argument.getString(0);
    String arg1 = argument.getString(1);

    Tuple result = new Tuple();
    result.addString(arg0);
    result.addString(arg1);
    result.addLong(timestamp.getTime());

    functionCall.getOutputCollector().add(result);
  }
}

Answer 1

it is not clear about Main.timeFrameMiddle.Could you please include Main class as well. If you are trying to get current time then you can do it within the cascading function.