ilistArray.stream().filter(ilist-ilist.tracking_id.equals(the-given-tracking-id)).collect(Collectors.toList()) - does this answer your question?

Demo:

package com.stackoverflow;

import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;

public class Prob10 {

    public static void main(String[] args) {
        ArrayList<Ilist> ilistArray = new ArrayList<Ilist>();
        ilistArray.add(new Ilist("Amit", "tid1", "Kolkata"));
        ilistArray.add(new Ilist("Ajay", "tid1", "Durgapur"));
        ilistArray.add(new Ilist("Bishnu", "tid2", "Bangalore"));
        ilistArray.add(new Ilist("Vineet", "tid3", "Noida"));

        List<Ilist> resultListArray = new ArrayList<Ilist>();

        resultListArray = ilistArray.stream().filter(ilist -> ilist.tracking_id.equals("tid1"))
                .collect(Collectors.toList());
        System.out.println(resultListArray);
    }
}

class Ilist {
    String name;
    String tracking_id;
    String place;

    Ilist(String n, String id, String pl) {
        this.name = n;
        this.tracking_id = id;
        this.place = pl;
    }
}

Given ilistArray this method returns a map of all the Ilist objects with the same trakingId:

public Map<String,List<Ilist>> mapTrakingId(List<Ilist> ilistArray){
    Map<String,List<Ilist>> result = new HashMap<>();
    for(Ilist i : ilistArray) {
        if(result.containsKey(i.trakingId)) {
            result.get(i.trakingId).add(i);
        }else {
            List<Ilist> iList = new ArrayList<>();
            iList.add(i);
            result.put(i.trakingId, iList);
        }
    }
    return result;
}

Or using Java Streams:

Map<String,List<Ilist>> trakingIdMap = ilistArray.stream()
                .collect(Collectors.groupingBy(i -> i.trakingId));

If you want to return the first element with the matching value, you need to write a method with a list as first parameter and a value-to-find as second parameter, that:

• traverses the list
• for each element, checks (with an if statement) whether the value is equal to your method parameter
• if it matches, return it immediately.

you can map to do this. trackingId as key.

public static Map<String,List<Ilist>> groupById(List<Ilist> iListArray){
        //same trackingId store to same List
        Map<String, List<Ilist>> trackIdMap=new HashMap<>();
        for(Ilist ilist:iListArray){
            trackIdMap.computeIfAbsent(ilist.trackingId, trackId -> new ArrayList<>()).add(ilist);
        }
        return trackIdMap;
}

for (Ilist il : ilistArray) {
        List<Ilist> sameTrackingIdList = ilistArray.stream()
                .filter(d -> d.getTrackingID().equals(il.getTrackingID())).collect(Collectors.toList());

        ilistMap.put(il.getTrackingID(), sameTrackingIdList);

    }
This code snippet resolved my issue. Thank you all. :)