Practical Real-time Data Processing and Analytics

peek

This is used to debug the tuples flowing between the operations. The following is the example using the previous functions:

topology.newStream("spout1", spout).flatMap(new SplitMapFunction()).map(new UpperCase()).peek(  new Consumer() {    @Override    public void accept(TridentTuple tuple) {      System.out.print("[");      for (int index = 0; index < tuple.size(); index++) {        System.out.print(tuple.get(index));        if (index < (tuple.size() - 1))        System.out.print(",");      }      System.out.println("]");      }});