I'm calling this function from a jUnit test case with the following information:
// abbr = "US";
// Countries = array of two objects one with iso2 = "us"
public Country getCountryFromAbbr(String abbr) {
abbr = abbr.toLowerCase();
for (int i = 0; i < Countries.size(); i++) {
Country country = Countries.get(i);
String iso2 = country.ISO2.toLowerCase();
String iso3 = country.ISO3.toLowerCase();
if (iso2.equals(abbr) || iso3.equals(abbr)) {
return country;
}
}
return null;
}
When I debug, the second object with ISO2 of us iso2.equals(abbr) is true and the other is false. However, country is not returned and the debugger finishes the loop and returns null.
I'm confused as true || false is true. Am I missing something?
Here's the mock of the countries:
List<Country> Countries = new ArrayList<Country>();
Country country = new Country();
country.CountryId = 1;
country.CountryName = "Great Britian";
country.ISO2 = "GB";
country.ISO3 = "GBR";
Countries.add(country);
Country usa = new Country();
usa.CountryId = Studio.USA_COUNTRY_ID;
usa.CountryName = "United States of America";
usa.ISO2 = "US";
usa.ISO3 = "USA";
Countries.add(usa);
return Countries;
EDIT:
I'm using Eclipse and debugging using my Droid X 2.3.3
Does it work fine with simple if condition?
if (iso2.equals(abbr)) {
return country;
}
if(iso3.equals(abbr)){
return country;
}
This looks like a job for Enum! (whoooooosh!)
public enum Country {
GREAT_BRITAIN("GB", "GBR"),
USA("US", "USA");
private String iso2;
private String iso3;
private Country(String iso2, String iso3){
this.iso2 = iso2;
this.iso3 = iso3;
}
public static Country getCountry(String a){
for (Country c : Country.values()){
if (c.iso2.equalsIgnoreCase(a) || c.iso3.equalsIgnoreCase(a)){
return c;
}
}
return null; // no country found!
}
}
If Country is immutable (you're not going to change any values inside it), then this is a neat way of doing it - and you can add id and name as attributes as well. And expose getters if you need access to those attributes.
Your current method accesses Countries as an instance variable, instead of as an argument to the method, so it's possible there are side-effects there.
Related
currently, I'm doing an assignment that deals with the ArrayList class.
at some point, I need to check of the id of the instructor and make sure that the instructor is not added twice to the ArrayList, so I made a for loop to go through all the id that has been registered and get the id and check if it exists already
the problem is when I use the method " .size()" in the loop, the JVM throws NullPointerException
and I don't know why.
==========================================================================
what I need to read is this:
\\name - id - dateOfBirth - gender - degree - speciality - city - availability
Amanda Smith, 102020, 320101200000, M, PhD, Software Engineering, NewYork, true
=======================================================================
this is the code:
public static void main(String[] args) {
/* NOTE: I HAVE A CLASS CALLED "UniversityMember" THAT IS A SUPERCLASS FOR "Instructor" CLASS */
//declare what I need
ArrayList<UniversityMember> membersList;
Scanner read = new Scanner("inputFile.txt");//the file contains the text above
//First: Split the line everytime the sign ", " shows
String[] line = read.nextLine().split(", ");
//Second: Assign each valuse to its correspondeding variable
String name = line[0];
String id = line[1];
long date = Long.parseLong(line[2]);
Date birthDate = new Date(date);
char gender = line[3].charAt(0);
String degree = line[4];
String specialization = line[5];
String address = line[6];
boolean availability = Boolean.parseBoolean(line[7]);
//check if the Id is registered already
for (int i = 0; i < membersList.size(); i++) { //ERROR OCCURE
if (membersList.get(i) == null) {
break;
}
if (membersList.get(i).id.equals(id)) {
System.out.println("The instructor is registered already, the ID is found in the system.");
System.exit(0);
}
}
//add and make a new object for the constructor
membersList.add(new Instructor(name, id, birthDate, gender, degree, specialization, address, availability));
System.out.println("The instructor is successfully added.");
}//end main
The problem is membersList doesn't exist when you call .size() on it
instead of
ArrayList<UniversityMember> membersList;
you need to initialize it
ArrayList<UniversityMember> membersList = new ArrayList<UniversityMember>();
You need to initialize the ArrayList.
Like that ArrayList membersList = new ArrayList();
After that, in the first size() returns 0 and not null. Remember all data structure must be initialize in java.
You haven't added anything to the membersList then asking for the size for something that has nothing in it.
Example of whats going on
String str;
for(int i = 0; i < str.length(); i++){
System.out.println("hey");
}
also you need to declare the array list like this
ArrayList<Method name> membersList = new ArrayList<Method name>();
also don't forget to import the ArrayList class
import java.util.ArrayList;
nvm I figured out that I haven't initialized my array ( ╥ω╥ )
I'll keep the question for others to be carefull
==================================================
The code after fixing it:
public static void main(String[] args) {
/* NOTE: I HAVE A CLASS CALLED "UniversityMember" THAT IS A SUPERCLASS FOR "Instructor" CLASS */
//declare what I need
ArrayList<UniversityMember> membersList;
Scanner read = new Scanner("inputFile.txt");//the file contains the text above
/* ===== FIXING THE ERROR ======*/
membersList = new ArrayList();
//First: Split the line everytime the sign ", " shows
String[] line = read.nextLine().split(", ");
//Second: Assign each valuse to its correspondeding variable
String name = line[0];
String id = line[1];
long date = Long.parseLong(line[2]);
Date birthDate = new Date(date);
char gender = line[3].charAt(0);
String degree = line[4];
String specialization = line[5];
String address = line[6];
boolean availability = Boolean.parseBoolean(line[7]);
//check if the Id is registered already
for (int i = 0; i < membersList.size(); i++) {
if (membersList.get(i) == null) {
break;
}
if (membersList.get(i).id.equals(id)) {
System.out.println("The instructor is registered already, the ID is found in the system.");
System.exit(0);
}
}
//add and make a new object for the constructor
membersList.add(new Instructor(name, id, birthDate, gender, degree, specialization, address, availability));
System.out.println("The instructor is successfully added.");
}//end main
I have a very strange problem. I'm trying to show in a basket the price of products. When I run the code and add a product to the basket, I can see the name of the product but I can't see its price. When I click back to a previous page and add another product, I am able to see its price. There is no error message.
Also, when I try to debug this program, everything works. The problem appears only when I'm not debugging. The problem is closely connected with these two variables as indicated below. I think that these variables are 0 which is later printed on the screen. But I don't know why they are sometimes 0 and sometimes not. I also tried to set breakpoints on:
dataService.getQuantityOfDays();
dataService.getQuantityOfBreakfasts();
When I assign values to these two variables in Data class everything is ok (not 0).
Controller code:
#RequestMapping("/basket/{roomName}")
public String createBasket(Model model, #PathVariable("roomName") String roomName){
Floor currentFloor = floorService.getCurrentFloor();
User currentUser = userService.getCurrentUser();
this.roomName = roomName;
if(currentFloor != null){
Room currentRoom = roomService.getRoomByName(roomName, currentFloor);
Authentication auth = SecurityContextHolder.getContext().getAuthentication();
String name = auth.getName();
if(currentUser == null){
userService.setCurrentUser(userService.getUserByName(name)); // wykona sie jesli nie zakladamy konta w danej sesji
}
Basket basketToSave = new Basket(userService.getCurrentUser());
BasketItem basketItem = new BasketItem(currentRoom);
int quantityOfDays = dataService.getQuantityOfDays(); //<--problem
int quantityOfBreakfast = dataService.getQuantityOfBreakfasts(); //<--problem
int priceForOneBreakfast = 17;
int priceForOneDay = currentRoom.getPriceForOneDay();
int wholePrice = quantityOfDays * priceForOneDay + quantityOfBreakfast * priceForOneBreakfast;
basketItem.setPrice(wholePrice);
basketItem.setQuantityOfDays(quantityOfDays);
basketItem.setQuantityOfBreakfast(quantityOfBreakfast);
Set<BasketItem> basketItemList = new HashSet<BasketItem>();
basketItemList.add(basketItem);
basketService.countBasketPrice(basketItemList, basketToSave);
basketToSave.setBasketItems(basketItemList);
basketItem.setBasket(basketToSave);
currentRoom.setBasketItemList(basketItemList);
boolean ifWasAnUpdate = basketService.save(basketToSave); // metoda save oprócz zapisu lub nadpisania zwraca co się wydarzyło (true - jesli nadpisywaliśmy koszyk)
if(ifWasAnUpdate){
basketItem.setBasket(basketService.get(basketToSave.getUser())); // jeżeli dodaje coś do koszyka (a nie tworzę go od nowa), muszę ustawić basketItemowi
} // koszyk, który już istnieje, a nie ten, który stworzyłem wcześniej w klasie BasketController.
// W tym celu pobieram go z bazy.
basketItemService.save(basketItem);
}
model.addAttribute("basket", basketService.get(currentUser));
model.addAttribute("days", dataService.getQuantityOfDays());
return "basket";
}
EDIT:
It's a repository code.
#Repository
public class DataRepositoryImpl implements DataRepository {
private int quantityOfDays;
private int quantityOfBreakfasts;
public void setQuantityOfDaysAndBreakfasts(String text) {
List<Integer> listOfIndexes = new ArrayList<Integer>();
for(int i=0;i<text.length();i++){
if(text.charAt(i) != '1'){
listOfIndexes.add(i);
}
}
char znak = text.charAt(listOfIndexes.get(0));
this.quantityOfDays = Character.getNumericValue(text.charAt(listOfIndexes.get(0))); // <- I put breakpoint here
this.quantityOfBreakfasts = Character.getNumericValue(text.charAt(listOfIndexes.get(1))); // <- I put breakpoint here
}
public int getQuantityOfDays() {
return this.quantityOfDays;
}
public int getQuantityOfBreakfasts() {
return this.quantityOfBreakfasts;
}
}
A problem can be also in basket save. Firslty when I can see only zeros I persist basket, then I'm only updating it.
Save & update methods:
public boolean save(Basket basketToSave) {
List<Basket> listOfAllBaskets = getAll();
boolean save = true;
boolean ifWasAnUpdate = false;
for(Basket basket: listOfAllBaskets){
if(basketToSave.getUser().equals(basket.getUser())){
save = false;
}
}
if(save){
emManager.persist(basketToSave);
}else{
updateBasket(basketToSave);
ifWasAnUpdate = true;
}
return ifWasAnUpdate;
}
public void updateBasket(Basket basket) {
Basket basketFromDatabase = get(basket.getUser());
basketFromDatabase.setBasketItems(basket.getBasketItems());
basketFromDatabase.setPrice(basket.getPrice());
emManager.merge(basketFromDatabase);
}
EDIT
I'm calling setQuantityOfDaysAndBreakfasts(text) earlier in this apllication. In this controller I'm only setting these values to basketItem class. I'll change this controller. Here another controller where I call setQuantityOfDaysAndBreakfasts(text).
#RequestMapping(value = "/room/rest", method = RequestMethod.POST, consumes = {"application/json"})
public void data(#RequestBody Data request){
String text = request.getText();
dataService.setQuantityOfDaysAndBreakfasts(text);
}
You are calling setQuantityOfDaysAndBreakfasts() after you get the value from your dataService. The value for quantityOfDays and quantityOfBreakfasts are only set when that method is called.
There are several things you should also examine.
As #NathanHughes points out, it's best to put your complex logic in your service layer and leave the controller to simply route requests. This is also true of your repository class. You should keep this very simple as the next developer reading your code is not going to expect to find any logic that doesn't simply read or write to your data source. (See Single Responsibility Principle.) It will also reduce code duplication in the future and as a result, reduce your time maintaining and fixing bugs.
For example, this code:
List<Integer> listOfIndexes = new ArrayList<Integer>();
for(int i=0;i<text.length();i++){
if(text.charAt(i) != '1'){
listOfIndexes.add(i);
}
}
char znak = text.charAt(listOfIndexes.get(0));
Should be refactored to a separate method entirely that can be made static and would not belong in that class.
I have a csvfile
id|name
1|PC
2|Activation
3|USB
public class TESTResult
{
private Long id;
private String name;
private Float score;
// with setters & getters
}
public class TEST
{
private Long id;
private String name;
// with setters & getters
}
public class JobTESTTagger {
private static Version VERSION;
private static CharArraySet STOPWORDS;
private static RewriteMethod REWRITEMETHOD;
private static Float MINSCORE = 0.0001F;
static {
BooleanQuery.setMaxClauseCount(100000);
VERSION = Version.LUCENE_44;
STOPWORDS = StopAnalyzer.ENGLISH_STOP_WORDS_SET;
REWRITEMETHOD = MultiTermQuery.CONSTANT_SCORE_FILTER_REWRITE;
}
public static ArrayList<TESTResult> searchText(String text, String keyId,
List<TEST> TESTs) {
ArrayList<TESTResult> results = new ArrayList<TESTResult>();
MemoryIndex index = new MemoryIndex();
EnglishAnalyzer englishAnalyzer = new EnglishAnalyzer(VERSION,STOPWORDS);
QueryParser parser = new QueryParser(VERSION, "text", englishAnalyzer);
parser.setMultiTermRewriteMethod(REWRITEMETHOD);
index.addField("text", text, englishAnalyzer);
for (int i = 0; i < TESTs.size(); i++) {
TEST TEST = TESTs.get(i);
String criteria = "\"" + TEST.getName().trim() + "\"";
if (criteria == null || criteria.isEmpty())
continue;
criteria = criteria.replaceAll("\r", " ");
criteria = criteria.replaceAll("\n", " ");
try {
Query query = parser.parse(criteria);
Float score = index.search(query);
if (score > MINSCORE) {
int result = new TESTResult(TEST.getId(), TEST.getName(),score);
results.add(result);
}
} catch (ParseException e) {
System.out.println("Could not parse article.");
}
}
return results;
}
public static void main(String[] args) {
ArrayList<TESTResult> testresults = searchText(text, keyId, iths);
CsvReader reader = new CsvReader("C:\a.csv");
reader.setDelimiter('|');
reader.readHeaders();
List<TEST> result = new ArrayList<TEST>();
while (reader.readRecord()) {
Long id = Long.valueOf(reader.get("id").trim());
String name = reader.get("name").trim();
TEST concept = new TEST(id, name);
result.add(concept);
}
String text = "These activities are good. I have a good PC in my house.";
}
I am matching 'activities' to Activation. How is it possible. Can anybody tell me how Lucene matches the words.
Thanks
R
EnglishAnalyzer, along with most language-specific analyzers, uses a stemmer. This means that it reduces terms to a stem (or root) of the term, in order to attempt to match more loosely. Mostly this works well, removing suffixes and matching up derived words to a common root. So when I search for "fish", I also find "fished", "fishing" and "fishes".
In this case though, both "activities" and "activation" both reduce to the root of "activ", resulting in the match you are seeing. Another example: "organ", "organic" and "organize" all have the common stem "organ".
You can stem or not, neither approach is perfect. If you don't stem you'll miss relevant results. If you do, you'll hit some odd irrelevant results.
To deal with specific problematic cases, you can define a stemmer exclusion set in EnglishAnalyzer to prevent stemming just on those specific problematic terms. In this case, I would think of "activation" as the probable term to prevent stemming on, though you could go either way. So I could do something like:
CharArraySet stemExclusionSet = new CharArraySet(VERSION, 1, true);
stemExclusionSet.add("activation");
EnglishAnalyzer englishAnalyzer = new EnglishAnalyzer(VERSION, STOPWORDS, stemExclusionSet);
I'm working in Eclipse (Android). In the following blocks, EmployeeInt and RestaurantInt are data types and query() opens a connection to the database and parses the results. When I print the query results, I get identical strings, but the boolean is still false. I've tried trimming the strings, but that didn't help.
public boolean verifyEmployee(String email, String password) {
ArrayList<EmployeeInt> employeeEmailID = query("SELECT employeeID FROM employees WHERE emailAddress = \'"+email+"\'");
ArrayList<EmployeeInt> employeePasswordID = query("SELECT employeeID FROM employees WHERE password = \'"+password+"\'");
String stringEmployeeEmailID = employeeEmailID.toString();
String stringEmployeePasswordID = employeePasswordID.toString();
if(stringEmployeeEmailID.equals(stringEmployeePasswordID)) {
return true;
} else {
return false;
}
}
Executing the above gives me false, while executing the following block (virtually identical) gives me true.
public boolean verifyRestaurant(String email, String password) {
ArrayList<RestaurantInt> restaurantEmailID = query("SELECT restaurantID FROM restaurants WHERE emailAddress = \'"+email+"\'");
ArrayList<RestaurantInt> restaurantPasswordID = query("SELECT restaurantID FROM restaurants WHERE password = \'"+password+"\'");
String stringRestaurantEmailID = restaurantEmailID.toString();
String stringRestaurantPasswordID = restaurantPasswordID.toString();
if(stringRestaurantEmailID.equals(stringRestaurantPasswordID)) {
return true;
} else {
return false;
}
}
Can anyone point out my mistake?
EDIT
I changed it to this and it worked:
public boolean verifyEmployee(String email, String password) {
ArrayList<EmployeeInt> employeeEmailID = query("SELECT * FROM employees WHERE emailAddress = \'"+email+"\'");
ArrayList<EmployeeInt> employeePasswordID = query("SELECT * FROM employees WHERE password = \'"+password+"\'");
int intEmployeeEmailID = employeeEmailID.get(0).getID();
int intEmployeePasswordID = employeePasswordID.get(0).getID();
if(intEmployeeEmailID==intEmployeePasswordID) {
return true;
} else {
return false;
}
}
I know I could also use return (condition), but I would like to add some messages if the login fails, something like:
System.err.println("email address and password do not correspond");
I'm not making an app to publish, it's merely for an assignment. Thanks for the help!
You are calling toString() on an ArrayList. Two different ArrayList objects will return two different toString() strings. You probably meant to get the first element of the ArrayList, and convert THAT to a string.
Example
EmployeeInt is your custom object. In my example, I assume it has some int field that can be retreived with getID().
ArrayList<EmployeeInt> idList = query("SELECT employeeID FROM employees WHERE emailAddress = \'"+email+"\'");
int ID = idList.get(0).getID();
stringEmployeeEmailID = String.valueOf(ID);
This may be easier to read than code:
query() returns an ArrayList
We extract the first element of the ArrayList - this is the part you left out
We get the ID of that element
We convert it to a String
I've researched can't find any relevant info. I have a result set that give me back distinct tagId's their can be multiple tagIds for same accountId's.
while(result_set.next()){
String tagId = result_set.getString("tagId");
String accountId = result_set.getString("accoundId");
// plenty of other fields being store locally
}
I need to store first accoundId(which is being done) & every subsequent iteration compare it with the previous Id to check for equality or not(if so same account).
I tried this and it failed horribly, after first iteration they'll continually be equal & I must be DUMB bc i though as long as I compare them before assignment global guy(previousId) should be holding the prior value.
String previousId = null;
while(result_set.next()){
String tagId = result_set.getString("tagId");
String accountId = result_set.getString("accoundId");
previousId = accountId;
}
Anyway I wanted my workflow to go something as follows:
while(result_set.next()){
if (previousId = null) {
// this would be the first iteration
}
else if (previousId.equals(accountId) {
// go here
} else {
// go here
}
}
If I've understood you well, this should work..
String previousId = null;
while(result_set.next()){
String tagId = result_set.getString("tagId");
String accountId = result_set.getString("accoundId");
if (previousId == null) {
// this would be the first iteration
} else if (previousId.equals(accountId) {
// go here
} else {
// go here
}
previousId = accountId;
}