How to use the variable inside the foreach loop in Java8?

As usual, when you decide to go functional, you must step back to a higher-level description of what you are aiming for, and then rewrite your code in FP style.

You want to determine the total count for three categories of events: "present", "absent", and "nottaken". Here is a suggestion on how to achieve it the FP-way (thanks to Stuart Marks for pointing out how to construct a library-provided frequency-counting collector):

import static java.util.stream.Collectors.counting;
import static java.util.stream.Collectors.groupingBy;

...

System.out.println(pestudents.stream().collect(groupingBy(pe -> {
    final List<ClassAttendanceChild> attendancelist = session.createQuery(
        "from ClassAttendanceChild where attendanceadded='" + day 
        + "' and pid.pId='" + promotionEntity.getpId() + "'")
      .list();
    return attendancelist.isEmpty()? "nottaken"
        : attendancelist.get(0).getStatus().equalsIgnoreCase("yes")?
            "present" : "absent";
  }, counting())));

You can notice that we have split the work into two stages: first we classify each PromotionEntity, then perform the frequency-counting reduction on those. The outcome is a mapping from category to its count.

For me, clarity of intent is enough of an advantage of the FP style, but this has the additional advantage of preparing the terrain for parallelization. In this particular case parallelization would probably not pay off because the bottleneck is the database, but generally, if FP style is adopted throughout, paralellization becomes a much closer target.

(Original code, with custom collector)

public static void main(String[] args) {
  final List<PromotionEntity> pestudents = ...your initialization...
  final Map<String, Integer> freqs = pestudents.stream().map(pe -> {
    final List<ClassAttendanceChild> attendancelist = session.createQuery(
           "from ClassAttendanceChild where attendanceadded='" + day + 
           "' and pid.pId='" + promotionEntity.getpId() + "'")
      .list();
    return attendancelist.isEmpty()? "nottaken" 
        : attendancelist.get(0).getStatus().equalsIgnoreCase("yes")?
            "present" : "absent";
  }).collect(toFrequencyMap());
  System.out.println(freqs);
}

static Integer zeroForNull(Integer i) { return i == null? 0 : i; }

static <K> Collector<K, Map<K, Integer>, Map<K, Integer>> toFrequencyMap() {
  return Collector.of(
      HashMap<K, Integer>::new,
      (acc, key) -> acc.compute(key, (x, count) -> zeroForNull(count) + 1),
      (acc, source) -> {
        source.forEach((key, sourceCount) ->
          acc.compute(key, (x,accCount) ->
            sourceCount + zeroForNull(accCount)));
        return acc;
      },
      Collector.Characteristics.UNORDERED);
}

You are not allowed to modify local variables defined outside of the method passed to forEach. They must be declared final or at least be effectively final, meaning that they are never changed after their initialization.

What you could do is to change present and the other local variables into instance variables or class variables, those you are allowed to modify.

That said, I would recommend you to keep the old syntax, it is much more suited for what you are trying to do.

To parallelise this code you can use AtomicInteger as your thread safe counter.

AtomicInteger present = new AtomicInteger();
AtomicInteger absent = new AtomicInteger();
AtomicInteger nottaken = new AtomicInteger();

pestudents.parallelStream().forEach(promotionEntity -> {
        List<ClassAttendanceChild> attendancelist = session.createQuery("from ClassAttendanceChild where attendanceadded='" + day + "' and pid.pId='" + promotionEntity.getpId() + "'").list();
        if (!attendancelist.isEmpty()) {
             ClassAttendanceChild attendenceDetails = (ClassAttendanceChild) attendancelist.get(0);
              if (attendenceDetails.getStatus().equalsIgnoreCase("yes")) {
                  present.incrementAndGet();
                  System.out.println("present = " + present);
            } else {
                  absent.incrementAndGet();
                  System.out.println("Absent = " + Absent);
            }
        } else {
              nottaken.incrementAndGet();
              System.out.println("nottaken = " + nottaken);
        }
    });