Java refactor code - arraylist contains with if / else
Is it possible to refactor below if the / else part in an elegant way? Please share your experiences and feedback.
if(onlineAreaPrioList.contains("ladies")){
dominantOnlineArea = "ladies";
}else if(onlineAreaPrioList.contains("kids")){
dominantOnlineArea = "kids";
}else if(onlineAreaPrioList.contains("men")){
dominantOnlineArea = "men";
}else if(onlineAreaPrioList.contains("home")){
dominantOnlineArea = "home";
}
Note: Priority = Ladies> Children> Men> Home
Output : values in hashmap: {men = 2, ladies = 2, home = 2, kids = 1}
values in onlineAreaPrioList: [men, women, domestic]
ComputedOnlineArea: ladies
Below is the entire code:
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import dto.ProductDTO;
public class Test {
static Map<String, Integer> freq = new HashMap<String, Integer>();
public static void main(String[] args) {
List<ProductDTO> recentlyBoughtList = recentlyBought();
List<ProductDTO> recentlyViewedList = recentlyViewed();
String finalOnlineArea = getDominantOnlineArea(recentlyViewedList,recentlyBoughtList);
System.out.println("ComputedOnlineArea: "+finalOnlineArea);
}
private static String getDominantOnlineArea(List<ProductDTO> recentlyViewedList,List<ProductDTO> recentlyBoughtList) {
for (ProductDTO productDTO: recentlyViewedList) {
countPrimaryOnlineArea(productDTO);
addSecondaryOnlineAreaWithPrimary(productDTO);
}
for (ProductDTO productDTO: recentlyBoughtList) {
countPrimaryOnlineArea(productDTO);
addSecondaryOnlineAreaWithPrimary(productDTO);
}
System.out.println("values in hashmap :"+freq);
return getOnlineAreaBasedOnDefaultPriorityOrder();
}
private static String getOnlineAreaBasedOnDefaultPriorityOrder() {
String dominantOnlineArea = null;
Set<String> onlineAreaPrioList = new HashSet<String>();
int maxValueInMap=(Collections.max(freq.values()));
for (Entry<String, Integer> entry : freq.entrySet()) {
if (entry.getValue()==maxValueInMap) {
//System.out.println(entry.getKey());
onlineAreaPrioList.add(entry.getKey());
}
}
System.out.println("values in onlineAreaPrioList :"+onlineAreaPrioList);
if(onlineAreaPrioList.contains("ladies")){
dominantOnlineArea = "ladies";
}else if(onlineAreaPrioList.contains("kids")){
dominantOnlineArea = "kids";
}else if(onlineAreaPrioList.contains("men")){
dominantOnlineArea = "men";
}else if(onlineAreaPrioList.contains("home")){
dominantOnlineArea = "home";
}
return dominantOnlineArea;
}
private static void countPrimaryOnlineArea(ProductDTO productDTO) {
String pOnlineArea = productDTO.getPrimaryOnlineAreaId();
if(OnlineAreaNotEmptyAndNotNull(pOnlineArea))
checkAndIncreaseOnlineAreaCount(pOnlineArea);
}
private static boolean OnlineAreaNotEmptyAndNotNull(String onLineArea) {
boolean onlineAreaFlag = false;
if(null!=onLineArea)
onlineAreaFlag = true;
return onlineAreaFlag;
}
private static void addSecondaryOnlineAreaWithPrimary(ProductDTO productDTO) {
String onlineArea = productDTO.getOnlineAreaIds();
if(OnlineAreaNotEmptyAndNotNull(onlineArea)) {
if(onlineArea.contains("|")) {
String[] onlineAreaSplit = onlineArea.split("\\|");
for(String online : onlineAreaSplit) {
checkAndIncreaseOnlineAreaCount(online);
}
}else {
checkAndIncreaseOnlineAreaCount(onlineArea);
}
}
}
private static void checkAndIncreaseOnlineAreaCount(String onlineArea) {
int count = freq.containsKey(onlineArea) ? freq.get(onlineArea) : 0;
freq.put(onlineArea, count + 1);
}
private static List<ProductDTO> recentlyBought() {
List<ProductDTO> recentlyBoughtList= new ArrayList<ProductDTO>();
ProductDTO productDTO1 = new ProductDTO();
productDTO1.setPrimaryOnlineAreaId("ladies");
productDTO1.setOnlineAreaIds("ladies");
ProductDTO productDTO2 = new ProductDTO();
productDTO2.setPrimaryOnlineAreaId("men");
//productDTO2.setOnlineAreaIds("men"); //comment
recentlyBoughtList.add(productDTO1);
recentlyBoughtList.add(productDTO2);
return recentlyBoughtList;
}
private static List<ProductDTO> recentlyViewed() {
List<ProductDTO> recentlyViewedList= new ArrayList<ProductDTO>();
ProductDTO productDTO1 = new ProductDTO();
productDTO1.setPrimaryOnlineAreaId("home");
productDTO1.setOnlineAreaIds("home");
ProductDTO productDTO2 = new ProductDTO();
//productDTO2.setPrimaryOnlineAreaId("men"); //comment
productDTO2.setOnlineAreaIds("men|kids");
recentlyViewedList.add(productDTO1);
recentlyViewedList.add(productDTO2);
return recentlyViewedList;
}
}
package dto;
public class ProductDTO {
private String primaryOnlineAreaId;
private String onlineAreaIds;
private String ageId;
public String getPrimaryOnlineAreaId() {
return primaryOnlineAreaId;
}
public void setPrimaryOnlineAreaId(String primaryOnlineAreaId) {
this.primaryOnlineAreaId = primaryOnlineAreaId;
}
public String getOnlineAreaIds() {
return onlineAreaIds;
}
public void setOnlineAreaIds(String onlineAreaIds) {
this.onlineAreaIds = onlineAreaIds;
}
public String getAgeId() {
return ageId;
}
public void setAgeId(String ageId) {
this.ageId = ageId;
}
}
source to share
One way is to convert the chain if
to an extended loop for
:
for (String kind : new String[] {"ladies", "kids", "men", "home"}) {
if (onlineAreaPrioList.contains(kind)) {
dominantOnlineArea = kind;
break;
}
}
Consider substitution "magic strings" (i.e. "ladies"
, "kids"
, "men"
and "home"
) of string constants defined at the appropriate level.
Another approach is to replace "magic strings" with enum
s, which will allow you to switch the type onlineAreaPrioList
to EnumSet
:
public enum PriorityKind {
LADIES, KIDS, MEN, HOME
}
...
EnumSet<PriorityKind> onlineAreaPrioList = new EnumSet<>();
source to share
In fact, keeping them like this String
is probably not a good idea, since you want them to be explicitly prioritized. A definition Enum
would probably be better:
enum Priority {
LADIES(1),
KIDS(2),
MEN(3),
HOME(4);
private final int weight;
Priority(int weight) {
this.weight = weight;
}
public int getWeight() {
return weight;
}
}
And then the usage would be:
Stream.of(Priority.KIDS, Priority.MEN)
.max(Comparator.comparing(Priority::getWeight))
.orElse(null);
source to share