package no.steria.skuldsku.example.basic.impl;

import java.util.ArrayList;
import java.util.List;

import no.steria.skuldsku.example.basic.PlaceDao;

public class InMemoryPlaceDao implements PlaceDao {
    private static List<String> places = new ArrayList<>();

    private static void add(String name) {
        synchronized (places) {
            places.add(name);
        }
    }

    private static List<String> all() {
        synchronized (places) {
            return new ArrayList<>(places);
        }
    }

    @Override
    public void addPlace(String name) {
        InMemoryPlaceDao.add(name);
    }

    @Override
    public List<String> findMatches(String part) {
        if (part == null) {
            return all();
        }
        ArrayList<String> result = new ArrayList<>();
        for (String place : all()) {
            if (place.toUpperCase().contains(part.toUpperCase())) {
                result.add(place);
            }
        }
        return result;
    }
}

package no.steria.skuldsku.example.basic.impl;

import java.util.ArrayList;
import java.util.List;

import no.steria.skuldsku.example.basic.PlaceDao;

public class InMemoryPlaceDao implements PlaceDao {
    private static List<String> places = new ArrayList<>();

    private static void add(String name) {
        synchronized (places) {
            places.add(name);
        }
    }

    private static List<String> all() {
        synchronized (places) {
            return new ArrayList<>(places);
        }
    }

    @Override
    public void addPlace(String name) {
        //InMemoryPlaceDao.add(name);
    }

    @Override
    public List<String> findMatches(String part) {
        if (part == null) {
            return all();
        }
        ArrayList<String> result = new ArrayList<>();
        for (String place : all()) {
            if (place.toUpperCase().contains(part.toUpperCase())) {
                result.add(place);
            }
        }
        return result;
    }
}

--- 
+++ 
@@ -22,7 +22,7 @@
 
     @Override
     public void addPlace(String name) {
-        //InMemoryPlaceDao.add(name);
+        InMemoryPlaceDao.add(name);
     }
 
     @Override
Remove result of running demo.
