Develop Reference

Spring-hibernate debug

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.

getJSONObject and subsequent getString returns null

This is a very straightforward question, but this error is very mysterious to me as I have not been able to find a solution or anyone else who has had this problem. I've also used a very similar technique in another activity and it worked just fine. I am making an android application which makes a POST request to a server. The response is a JSONObject that must be parsed into a number and another JSONObject which must also be parsed, and its values assigned to an array of CurrentGame objects. The first call to getJSONObject works fine, but calling getString on that JSONObject returns the following error:
java.lang.NullPointerException: Attempt to write to field 'java.lang.String com.xxxxx.xxxxx.CurrentGame.oppEmail' on a null object reference
Here is my java code:
private void handleResponse(JSONObject response){
int numGroups = 0;
try{
numGroups = response.getInt("Number");
}catch(JSONException e){
e.printStackTrace();
}
Log.i("Number of Groups", String.valueOf(numGroups));
CurrentGame[] currentGames = new CurrentGame[numGroups];
JSONObject current;
int yourTurn = 0;
for(int i = 0; i < numGroups; i++){
try{
current = response.getJSONObject(String.valueOf(i));
Log.i("Current JSONObject: ", String.valueOf(current));
if(current.has("OppEmail")){
currentGames[i].oppEmail = current.getString("OppEmail");
}
if(current.has("OppName")) {
currentGames[i].oppName = current.getString("OppName");
}
if(current.has("Group")) {
currentGames[i].group = current.getString("Group");
}
if(current.has("YourTurn")) {
yourTurn = current.getInt("YourTurn");
}
if(yourTurn == 0){
currentGames[i].yourTurn = true;
}
else{
currentGames[i].yourTurn = false;
}
}
catch (JSONException e){
e.printStackTrace();
}
}
}
Shouldn't the JSONObject.has() check at least be preventing this error?
I know the first getInt() and getJSONObject are working. Heres the Log:
06-21 21:58:56.644 20116-20116/com.xxxxx.xxxxx D/Response:﹕ {"Number":2,"0":{"Group":"Test Group 1","OppEmail":"xxxxx#xxxxx.edu","OppName":"MikeyP","YourTurn":0},"1":{"Group":"Test Group 2","OppEmail":"xxxxx#xxxxx.edu","OppName":"MikeyP","YourTurn":1}}
06-21 21:58:56.644 20116-20116/com.xxxxxx.xxxxxt I/Number of Groups﹕ 2
06-21 21:58:56.644 20116-20116/com.xxxxx.xxxxx I/Current JSONObject﹕ {"Group":"Test Group 1","OppEmail":"xxxxxx#xxxxx.edu","OppName":"MikeyP","YourTurn":0}
Here's the server code:
$games['Number'] = $numgames;
if($numgames > 0){
$i = 0;
while($row = mysqli_fetch_array($getgames)){
$currGame['Group'] = $row['GroupName'];
// Get the opponent's email and username
if($row['Player1'] != $email){
$opponent = $row['Player1'];
$currGame['OppEmail'] = $opponent;
$sql = "SELECT Username FROM users WHERE Email = '".$opponent."'";
$username = mysqli_query($conn, $sql);
$row2 = mysqli_fetch_assoc($username);
$currGame['OppName'] = $row2['Username'];
}
else if($row['Player2'] != $email){
$opponent = $row['Player2'];
$currGame['OppEmail'] = $opponent;
$sql = "SELECT Username FROM users WHERE Email = '".$opponent."'";
$username = mysqli_query($conn, $sql);
$row2 = mysqli_fetch_assoc($username);
$currGame['OppName'] = $row2['Username'];
}
// Determine if it is this player's turn
if($row['CurrentPlayer'] != $email){
$currGame['YourTurn'] = 0;
}
else{
$currGame['YourTurn'] = 1;
}
$games[$i] = $currGame;
$i++;
}
}
//Echo array of groups
header('Content-Type: application/json');
$response = json_encode($games);
echo $response;
Thank you in advance for any ideas as to what I'm doing wrong here. I know similar questions have been asked about getString() returning null, but having read them all I'm still very stumped.

Problem is caused by :
currentGames[i].oppEmail = current.getString("OppEmail");
line.
Because currentGames Array is initialized with size 2 but not added any item of type CurrentGame.
Instead of using currentGames[i].oppEmail create a object of CurrentGame class add all values then add it in currentGames Array like:
CurrentGame objCurrentGame=new CurrentGame();
if(current.has("OppEmail")){
objCurrentGame.oppEmail = current.getString("OppEmail");
}
... same for other fields
...
//Add objCurrentGame to Array
currentGames[i]=objCurrentGame;

Parsing json this way is not robust and error prone, it is recommended to use such libraries as
Gson
Jackson
Retrofit
as these open source libraries offer stable implementation for such purposes and there is no need to reinvent the wheel yourself.
example:
YourPojoClass obj = new Gson().fromJson("{SomeJsonString}", YourPojoClass.class);
In this way, you get the strongly typed pojo instance.You don't even need write the POJO class yourself, and there are many online service that can generate the POJO class out of json strings:
http://www.jsonschema2pojo.org/
http://pojo.sodhanalibrary.com/

trouble setting a string value

I am working on a project. When I set a String I'd like the setting method to test for a null value. If there is a null value I'd like set the global variable to "purple hotdog". I get an error that says Type mismatch: cannot convert from String to boolean and I'm not sure why. Eventually I'd like to call a method that returns a value that encryptedBlock is set to instead of setting the value to "purple hotdog", but baby steps for now. Here is my code, and thanks for the help.
private String encryptedBlock = null;
public void setEncryptedBlock(String encryptedBlock) {
if (this.encryptedBlock.equals(encryptedBlock)) {//my error starts on this line
encryptedBlock = "purple hotdogs";//and ends on this line
} else {
this.encryptedBlock = encryptedBlock;
}
}

here is proper code:
private String encryptedBlock = null;
public void setEncryptedBlock(String encryptedBlock) {
if (encryptedBlock == null)
encryptedBlock = "purple hotdogs";
this.encryptedBlock = encryptedBlock;
}

Storing the details in list and then on inspecting storing in different list

I have a pojo like this..
public class abcObject {
private long id;
private long version;
private DateTime created ;
private String status;
}
and its corresponding hbm as internally it data is being stored in the table through hibernate now please advise as the status can have values like pass or failNow i have to filter the value whether it is pass or fail as rite now i can check its value by inspecting and depending upon that I have to put them into the seprate list, I have done through this way
List<abcObject> successful = new ArrayList <abcObject>();
List<abcObject> exception = new ArrayList <abcObject>();
List<abcObject> failure = new ArrayList <abcObject>();
//getting the list from the database into the parameter allabcObjects
List<abcdObject> allabcObjects = abcHome.getabcObjects(fileIdentifier);
if (abcObjects !=null && abcObjects.size() > 0) {
for (abcObject f : allabcObjects) {
}
Now please advise as I am using the for loop to iterate over each object then how by inspecting that is f.getstatus() method and if it is fail then it should stote all the details in fail list and if it it is success then it should store in successful list , please advise how to achieve this

Just compare object with your strings
List<abcObject> successful = new ArrayList <abcObject>();
List<abcObject> exception = new ArrayList <abcObject>();
List<abcObject> failure = new ArrayList <abcObject>();
//getting the list from the database into the parameter allabcObjects
List<abcdObject> allabcObjects = abcHome.getabcObjects(fileIdentifier);
if (abcObjects !=null && abcObjects.size()>0)
{
for (abcObject f : allabcObjects) {
if( "pass".equalsIgnoreCase(f.getStatus()) ) {
successful.add( f );
} else if ( "failNow".equalsIgnoreCase(f.getStatus()) {
failure.add( f );
}
}
}
Just to point out some things. Even better would be to create static final string, for your success / fail string like this:
private static final String SUCCESS = "success";
private static final String FAIL = "failNow";
....
if( SUCCESS.equalsIgnoreCase(f.getStatus()) ) {
successful.add( f );
} else if ( FAIL.equalsIgnoreCase(f.getStatus()) {
failure.add( f );
}
Comparing SUCCESS with f.getStatus(), instead of inverse, gives us certainty that there won't be NullPointerException if somehow f would be null

Your for loop would read:
for (abcObject f : allabcObjects) {
String status = f.getstatus();
if(status.equals("fail")){
failure.add(f);
}
else{
otherList.add(f);
}
}
You'll also need to declare the otherList, i.e.
List<abcObject> otherList = new ArrayList<abcObject>();
This assumes that your getstatus() method returns a String "fail" if it fails.

NSNotFound equivalent in Java

I need to know if there is a way to say that int type is not found in Java Android.
I'm writing an android application,which is actually written first for Iphone, and have a little issue. At some point I have to check if the int type which returns a method is not found and if it's true do some calculations. The problem is that when I did that in Java as if(Id==0) it's throwing me an exception even if the Id is 0.
this is my method :
private static int localUserIdByServerUserId(int serverUserId, String serverName){
dbHelper = new DataBaseHelper(context, "stampii_sys_tpl.sqlite", null, 1);
dbHelper.getDatabase();
String query = "SELECT id FROM users WHERE objectId = "+serverUserId+" AND serverName = '"+serverName+"' LIMIT 1";
ArrayList<String> result = new ArrayList<String>();
cursor = dbHelper.executeSQLQuery(query);
cursor.moveToFirst();
while(!cursor.isAfterLast()) {
result.add(cursor.getString(cursor.getColumnIndex("id")));
cursor.moveToNext();
}
Log.i("result ","Result : "+result.toString());
Log.i("CURSOR ","Cursor Position : "+cursor.getPosition());
int uuid = Integer.parseInt(result.get(cursor.getColumnIndex("objectId")+1));
Log.w("localUSerByIdServerUserId","LocalUserByIdServerUserId result : "+uuid);
cursor.close();
return uuid;
and here is how I'm using it :
int uuId = rpc.lUserIdByServerUserId(userId,newServerName);
Log.w("uuId","uuId : "+uuId);
if(uuId==0){
// do some calculations
}
Any suggestions ?

lUserIdByServerUserId() could throw an exception when the user is not found.
e.g.
try {
int uuId = rpc.lUserIdByServerUserId(userId,newServerName);
Log.w("uuId","uuId : "+uuId);
}
catch (NotFoundException nfe) {
// do some calculations
}
You will need to modify lUserIdByServerUserId() to throw the exception. You may also need to define your own NotFoundException class if a suitable exception doesn't already exist in the Java libraries.
EDIT:
Alternatively, following on from #mthpvg's answer, you could change lUserIdByServerUserId() to return an Integer type, which can be set to null if not found and tested.
e.g.
Integer uuId = rpc.lUserIdByServerUserId(userId,newServerName);
if (uuId == null) {
// Do some calculations
}