For the below piece of code Sonar throws me a critical violation - Correctness - Nullcheck of status value previously dereferenced
Can someone suggest on this on what am I doing wrong here?
code
public boolean isExactMacthBill(AddressResponse response) {
boolean exactMatch = false;
if (null != response && null != response.getHostResponse()) {
HostResponseDetail hostResponse = response.getHostResponse();
String addressStatus = hostResponse.getMatchStatus();
ResponseDetail status = hostResponse.getStatus();
String addressMatchCode = status.getCode();
if (null != response.getMatchedAddresses() && response.getMatchedAddresses().size() > 0 && status != null) {
if (addressStatus.equalsIgnoreCase(Constants.USPS_MATCH)
|| (addressStatus.equalsIgnoreCase(Constants.PARTIAL_MATCH)
&& addressMatchCode.equalsIgnoreCase("3SXU"))) {
exactMatch = true;
} else
exactMatch = false;
}
}
return exactMatch;
}
The actual problem is in the line after the highlighted one - you've got:
if (... && status != null)
Just remove that check and I think SonarLint will be happy. It unnecessary, because if status is null then status.getCode() will already have thrown an exception before you reach that condition.
Fundamentally, you need to know whether getStatus() should ever return null - whether you have to handle that situation explicitly. If you do, you should check it before your call to status.getCode(), and react accordingly. If you don't, it's fine to call the getCode() method - if your assumption is incorrect, you'll get a NullPointerException as normal, which is probably the most appropriate result for the scenario of "the world isn't as I expect it to be". But you shouldn't try to "handle" it being null after you've already depended on it being non-null.
status can be null when it is received from hostResponse.getStatus();; so when the line String addressMatchCode = status.getCode(); is called it can result in a Null Reference Exception.
You should verify all the variables if there are null before calling methods on them.
Move your addressMatchCode inside your if condition which null check the status.
public boolean isExactMacthBill(AddressResponse response) {
boolean exactMatch = false;
if (null != response && null != response.getHostResponse()) {
HostResponseDetail hostResponse = response.getHostResponse();
String addressStatus = hostResponse.getMatchStatus();
ResponseDetail status = hostResponse.getStatus();
if (null != response.getMatchedAddresses() && response.getMatchedAddresses().size() > 0 && status != null) {
String addressMatchCode = status.getCode();
if (addressStatus.equalsIgnoreCase(Constants.USPS_MATCH)
|| (addressStatus.equalsIgnoreCase(Constants.PARTIAL_MATCH)
&& addressMatchCode.equalsIgnoreCase("3SXU"))) {
exactMatch = true;
} else
exactMatch = false;
}
}
return exactMatch;
}
Related
There are 7 rows of output for table, how can I modify this so row 6 displays either of the three providers.
I tried something like this :
template.getProvider2() != null || template.getProvider3() != null ||
template.getProvider1() != null ?
template.getProvider2().getBusinessUnit(): "" ||
template.getProvider3().getBusinessUnit(): "" ||
template.getProvider3().getBusinessUnit(): "",
which gives me an error of StringBuilder not accepting the OR operator,
I'd appreciate any help on this.
Thanks
Here is my code:
public GetEmailTemplatesResponse getEmailTemplates() throws Exception {
StringBuilder stringBuilder = new StringBuilder();
String tableRow = "<tr><td>%s</td><td>%s</td><td>%s</td><td>%s</td><td>%s</td><td>%s</td><td>%s</td></tr>";
Map<String, EmailTemplate> templates = templateRedisCacheReader.getTemplatesByCacheType(CacheType.EMAIL_TEMPLATE);
templates.values()
.forEach(template -> stringBuilder.append(String.format(tableRow,
template.getTemplateId(),
template.getProvider1() != null ? template.getProvider1().getId() : "",
template.getProvider2() != null ? template.getProvider2().getId() : "",
template.getProvider3() != null ? template.getProvider3().getId() : "",
template.getEnv(),
template.getProvider2() != null ? template.getProvider2().getBusinessUnit(): "", // <--
template.getPriority()))
);
I tried to check if all the providers are null and if one of them is not null , then display bussiness unit for that provider
There's a function commonly used in SQL that returns the first non-null parameter called "coalesce". You could write a Java equivalent of that.
Object coalesce(Object... objects) {
for (Object obj : objects) {
if(obj != null) return obj;
}
return null;
}
...
Provider firstNonNullTemplate=(Provider) coalesce(template.getProvider1(), template.getProvider2(), template.getProvider3());
I'm currently investing a lot of time in cleaning up my code.
I have a lot of If statements that handles my signup form in frontend.
I have a feeling that after reading the book "Clean code". That this is just ugly, however I didn't seem to find any "amazing/incredible" cleanup format for my code below.
lets say I have 15 more if-statements then this will cause a lot of duplicates, so are there any major improvements possible?
User userByUsername = userRepo.findByUsername(user.getUsername());
User userByEmail = userRepo.findUserByEmail(user.getEmail());
if (userByUsername != null && userByEmail != null) {
throw new AccountException("Email and username already exist");
}
if (userByUsername != null) {
throw new AccountException("Username already exist");
}
if (userByEmail != null) {
throw new AccountException("Email already exist");
}
Another example with another method:
public void addConditions(ReservationDto reservationDto) {
long roomId = roomService.findRoomByRoomName(reservationDto.getRoomName()).getRoomId();
// Check for adding room: Roomcapacity for timeslote reached
// If maxCapacityAfternoon reached, then only add to afternoon possible
int roomCapacity = roomService.findRoomByRoomId(roomId).getCapacity();
boolean maxCapacityMorning = roomCapacity <= getNumberOfReservationsForRoomByDateVoormiddag(roomId, reservationDto.getDate());
boolean maxCapacityAfternoon = roomCapacity <= getNumberOfReservationsForRoomByDateNamiddag(roomId, reservationDto.getDate());
boolean isMorning = reservationDto.isMorning();
boolean isAfternoon = reservationDto.isAfternoon();
capacityConditions(reservationDto, maxCapacityMorning, maxCapacityAfternoon);
// Check: Reservation can only be made when it meets the following conditions
// - Same user
// - is active
// - Morning and date overlap
// - Afternoon and date overlap
Reservation mappedReservation = mapReservationDto(reservationDto);
int amountOfReservationsForDay = reservationRepo.existsReservationForDay(mappedReservation.getUsername(), mappedReservation.getDate());
if (isMorning && isAfternoon) {
if (amountOfReservationsForDay > 0) {
throw new ServiceException(RESERVATION_MSG + FOR_FULL_DAY + reservationDto.getDate());
}
if (reservationRepo.existsReservationForMorning(mappedReservation.getUsername(), mappedReservation.getDate()) > 0
|| reservationRepo.existsReservationForAfterNoon(mappedReservation.getUsername(), mappedReservation.getDate()) > 0
) {
throw new ServiceException(RESERVATION_MSG + "in de voor- of namiddag.");
}
}
if (isMorning && !isAfternoon) {
if (amountOfReservationsForDay > 0) {
throw new ServiceException(RESERVATION_MSG + FOR_FULL_DAY + reservationDto.getDate());
}
if (reservationRepo.existsReservationForMorning(mappedReservation.getUsername(), mappedReservation.getDate()) > 0) {
throw new ServiceException(RESERVATION_MSG + "in de voormiddag.");
}
}
if (!isMorning && isAfternoon) {
if (amountOfReservationsForDay > 0) {
throw new ServiceException(RESERVATION_MSG + FOR_FULL_DAY + reservationDto.getDate());
}
if (reservationRepo.existsReservationForAfterNoon(mappedReservation.getUsername(), mappedReservation.getDate()) > 0) {
throw new ServiceException(RESERVATION_MSG + "in de namiddag");
}
}
if (!isMorning && !isAfternoon) {
throw new ServiceException("Selecteer een tijdstip voor uw reservatie");
}
}
As you can see my project has a lot of conditions when I want to add a reservation. These are only the add conditions and don't take into account the room capacity check. Which is a long list of If's as well
You could create an enum for all the data validation exceptions that can be thrown
public enum DataValidationError {
USERNAME_EXISTS,
EMAIL_EXISTS,
...
}
public static class AccountException extends Exception {
private final List<DataValidationError> errors;
public AccountException(List<DataValidationError> errors) {
this.errors = errors;
}
public List<DataValidationError> getErrors() {
return errors;
}
}
Usage:
List<DataValidationError> errors = new ArrayList<>();
User userByUsername = userRepo.findByUsername(user.getUsername());
User userByEmail = userRepo.findUserByEmail(user.getEmail());
if (userByUsername != null) {
errors.add(DataValidationError.USERNAME_EXISTS);
}
if (userByEmail != null) {
errors.add(DataValidationError.EMAIL_EXISTS);
}
if (!errors.isEmpty()) {
throw new AccountException(errors);
}
This way you could add as many errors in the enum and keep adding them to a list and throw it only once at the end.
I am not sure if any really major improvement can be applied here. But for example since you are throwing the same type of exception you might play around your error message and throw exception only once. Like:
if(userByEmail != null || userByUsername != null){
String message = (userByEmail != null ? "Email" : "Username") + " already exist";
if(userByEmail != null && userByUsername != null){
message = "Email and username already exist";
}
throw new AccountException(message);
}
For make the code more extensible and close I would use a chain of validation for this kind of things. If you know about the SOLID principle, you have a problem of SRP and OCP. By implementing a chain of validation, you would have each node have one purpose and you could easily and more validation in the futur. After you just have to create a chain !
The thing is that validation is ONE thing, so I would too create lost of tiny function with good names, so the reader can "escape early" the reading if needed.
Here is the design patern that could help you: https://refactoring.guru/design-patterns/chain-of-responsibility
I think you repository should thow those exceptions too ! If you can't find a user throw an exception in your repository. You'll have less validation all over you code and it's easyer to read.
I'm a Kotlin developer but I'm working on a java project, but when converting the classes through the sdk, this error appears.
How to solve?
fun deviceIsConnected(): Boolean {
var connected = false
val myBluetoothAdapter = BluetoothAdapter.getDefaultAdapter()
if (myBluetoothAdapter != null && myBluetoothAdapter.isEnabled) {
if (configsAndModels!!.strMACPROBE != null && configsAndModels.strMACPROBE != "") {
val myDevice = myBluetoothAdapter.getRemoteDevice(
configsAndModels.strMACPROBE
)
try {
val m = myDevice.javaClass.getMethod("isConnected", null as Array<Class<*>>?)) //ERROR ON THIS LINE
connected = m.invoke(myDevice, *null as Array<Any?>?) as Boolean //ERROR ON THIS LINE
} catch (e: Exception) {
throw IllegalStateException(e)
}
}
}
return connected
}
JAVA :
public boolean deviceIsConnected() {
boolean connected = false;
BluetoothAdapter myBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if (myBluetoothAdapter != null && myBluetoothAdapter.isEnabled()) {
if (configsAndModels.getStrMACPROBE() != null && !configsAndModels.getStrMACPROBE().equals("")) {
BluetoothDevice myDevice = myBluetoothAdapter.getRemoteDevice(configsAndModels.getStrMACPROBE());
try {
Method m = myDevice.getClass().getMethod("isConnected", (Class[]) null);
connected = (boolean) m.invoke(myDevice, (Object[]) null);
} catch (Exception e) {
throw new IllegalStateException(e);
}
}
}
return connected;
}
Your Java code is explicitly passing a null array as the varargs, which is unnecessary. You could simplify your Java code to the following, which implicitly passes an empty array:
Method m = myDevice.getClass().getMethod("isConnected");
connected = (boolean) m.invoke(myDevice);
Likewise, in Kotlin, you can omit the varargs if you're passing zero values:
val m = myDevice.javaClass.getMethod("isConnected")
connected = m.invoke(myDevice) as Boolean
Java allows the null array for backward compatibility (to versions that used arrays instead of varargs) and because it doesn't have null safety. Since Kotlin doesn't need the backward compatibility, it doesn't need to support null arrays.
This is my code:
String invite = LogInUtil.getInvite(this);
System.out.println(invite.equals(null));
if ( invite != null){
System.out.println(invite);
System.out.println("=============================================="+(invite != null));
Invitation.setInvite(Long.valueOf(invite));
}
This is the method in LoginUtil:
public static String getInvite(Context mContext){
// 获取搜索记录文件内容
SharedPreferences sp = mContext.getSharedPreferences(PREFERENCE_NAME, 0);
String history = sp.getString(PREFERENCE_NAME, "");
String[] tmpHistory = history.split("==");
if (tmpHistory.length==2){
return tmpHistory[1];
}
return null;
}
This is the result in logcat:
I/System.out: false
I/System.out: null
I/System.out: ==============================================true
Is there anything wrong with my code? Maybe is a stupid question. I'm a fresher,and I need your help. TTThanks!
It might be case you are getting "null" as string value rather than null, try below code, if still not work try to clean your project
String invite = LogInUtil.getInvite(this);
if ( invite != null && !"null".equals(invite)){
System.out.println(invite);
System.out.println("=============================================="+(invite != null));
Invitation.setInvite(Long.valueOf(invite));
}
The error is at this line invite.equals(null). Your are checking null.equals(null) that's why it throws NULLPointerException.
Please correct it to the System.out.println(invite == null); so it will not throw exception.
Corrected Sample code
String invite = LogInUtil.getInvite(this);
System.out.println(invite == null);
if ( invite != null){
System.out.println(invite);
System.out.println("=============================================="+(invite != null));
Invitation.setInvite(Long.valueOf(invite));
}
Use StringUtils.empty() method for checking null and empty in case of string.
I think u are getting "null" string in ur invite variable.
I have a java code in which there are multiple return statements in a single method. But for code cleaning purpose, I can have only one return statement per method. What can be done to overcome this.
Here is a method from my code:-
public ActionForward login(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response) throws Exception {
// Kill any old sessions
//request.getSession().invalidate();
DynaValidatorForm dynaform = (DynaValidatorForm)form;
// validate the form
ActionErrors errors = form.validate(mapping, request);
if(!errors.isEmpty()) {
this.saveErrors(request, errors);
return mapping.getInputForward();
}
// first check if token is set
if(!isTokenValid(request, true)) {
String errmsg="There was a problem with your login. Please close your browser then reopen it and try again. Make sure to click the Login button only ONCE.";
request.setAttribute("errormessage", errmsg);
saveToken(request);
return mapping.findForward(ConstantLibrary.FWD_CONTINUE);
}
// check the form for input errors
String errmsg = checkInput(form);
if (errmsg != null) {
request.setAttribute("errormessage", errmsg);
saveToken(request);
return mapping.findForward(ConstantLibrary.FWD_CONTINUE);
}
// no input errors detected
String resumekey = null;
// check for valid login
ObjectFactory objFactory = ObjectFactory.getInstance();
DataAccessor dataAccessor = objFactory.getDataAccessor();
request.setCharacterEncoding("UTF-8");
String testcode = dynaform.getString("testcode").trim();
String studentname = dynaform.getString("yourname").trim();
String password = dynaform.getString("password").trim();
// 4/3/07 - passwords going forward are ALL lower case
if (!CaslsUtils.isEmpty(password)) {
password = password.toLowerCase();
}
try{
resumekey = new String(studentname.getBytes("ISO-8859-1"),"UTF-8");
} catch (Exception e) {
log_.error("Error converting item content data to UTF-8 encoding. ",e);
}
String hashWord = CaslsUtils.encryptString(password);
// Make sure this is short enough to fit in the db
if (hashWord.length() > ConstantLibrary.MAX_PASSWORD_LENGTH) {
hashWord = hashWord.substring(0, ConstantLibrary.MAX_PASSWORD_LENGTH);
}
Login login = dataAccessor.getLogin(testcode, hashWord, false);
if (login == null || !login.getUsertype().equals(Login.USERTYPE_SUBJECT)) {
request.setAttribute("errormessage", "Incorrect test code or password.");
saveToken(request);
return mapping.findForward(ConstantLibrary.FWD_CONTINUE);
}
// Check if the login has expired
if (login.getLoginexpires() != null && login.getLoginexpires().before(new Date())) {
request.setAttribute("errormessage", "Your login has expired.");
saveToken(request);
return mapping.findForward(ConstantLibrary.FWD_CONTINUE);
}
// Check if the password has expired
if (login.getPasswordexpires() != null && login.getPasswordexpires().before(new Date())) {
request.setAttribute("errormessage", "Your login password has expired.");
saveToken(request);
return mapping.findForward(ConstantLibrary.FWD_CONTINUE);
}
HttpSession session = request.getSession();
session.setAttribute(ConstantLibrary.SESSION_LOGIN, login);
session.setAttribute(ConstantLibrary.SESSION_STUDENTNAME, studentname);
List<Testtaker> testtakers = null;
try {
//invalidate the old session if the incoming user is already logged in.
synchronized(this){
invalidateExistingSessionOfCurrentUser(request, studentname, testcode);
testtakers = dataAccessor.getTesttakersByResumeKey(studentname, login);// Adding this code to call getTesttakersByResumeKey instead of getTesttakers to improve the performance of the application during student login
}
} catch (Exception e) {
log.error("Exception when calling getTesttakers");
CaslsUtils.outputLoggingData(log_, request);
throw e;
}
session = request.getSession();
if(testtakers!=null)
{
if(testtakers.size() == 0) {
// new student -> start fresh
log_.debug("starting a fresh test");
// if this is a demo test, skip the consent pages and dump them directly to the select test page
if (login.getTestengine().equals(Itemmaster.TESTENGINE_DEMO)) {
return mapping.findForward("continue-panel");
}
}
// send them to fill out the profile
// check for custom profiles
String[] surveynames = new String[4];
List<Logingroup> logingroups = dataAccessor.getLoginGroupsByLogin(login.getLoginid());
for(Logingroup logingroup : logingroups) {
Groupmaster group = logingroup.getGroupmaster();
log_.debug(String.format("group: {groupid: %d, grouptype: %s, groupname: %s}", new Object[] {group.getGroupid(), group.getGrouptype(), group.getName()}));
Set<Groupsurvey> surveys = group.getGroupsurveys();
if(surveys.size() > 0) {
// grab the first (and only) one
Groupsurvey survey = surveys.toArray(new Groupsurvey[0])[0];
if(group.getGrouptype().equalsIgnoreCase(Groupmaster.GROUPTYPE_CLASS)) {
surveynames[0] = survey.getSurveyname();
} else if (group.getGrouptype().equalsIgnoreCase(Groupmaster.GROUPTYPE_SCHOOL)){
surveynames[1] = survey.getSurveyname();
} else if (group.getGrouptype().equalsIgnoreCase(Groupmaster.GROUPTYPE_DISTRICT)){
surveynames[2] = survey.getSurveyname();
} else if (group.getGrouptype().equalsIgnoreCase(Groupmaster.GROUPTYPE_STATE)){
surveynames[3] = survey.getSurveyname();
}
}
}
// match the most grandular survey
for(int i=0; i < surveynames.length; ++i) {
if(surveynames[i] != null) {
saveToken(request);
return mapping.findForward("student-profile-"+surveynames[i]);
}
}
// no custom profile, send them to the default
saveToken(request);
return mapping.findForward("student-profile");
}
// get the set of availible panels
Set<Panel> availiblePanels = dataAccessor.getAvailiblePanels(login, studentname);
if(availiblePanels.size() == 0) {
// no panels availible. send to all done!
log_.debug(String.format("No panels availible for Login:%s with resumekey:%s", login.toString(), studentname));
session.setAttribute("logoutpage", true);
resetToken(request);
return mapping.findForward("continue-alldone");
}
//Eventum #427 - Prevent test takers from retaking a finished test.
TestSubjectResult testSubjecResult=dataAccessor.getTestSubjectResult(login, resumekey);
if(testSubjecResult != null){
if(testSubjecResult.getRdscore() != null && testSubjecResult.getWrscore() != null && testSubjecResult.getLsscore() != null && testSubjecResult.getOlscore() != null){
if(testSubjecResult.getRdscore().getFinishtime() != null && testSubjecResult.getWrscore().getFinishtime() != null && testSubjecResult.getLsscore().getFinishtime() != null && testSubjecResult.getOlscore().getFinishtime() != null){
log_.debug(String.format("Already completed all the Skill Tests.", login.toString(), studentname));
session.setAttribute("logoutpage", true);
resetToken(request);
return mapping.findForward("continue-alldone");
}
}
}
// get a list of resumeable testtakers
List<Testtaker> resumeableTesttakers = new ArrayList<Testtaker>();
for(Testtaker testtaker : testtakers) {
if(testtaker.getPhase().equals(ConstantLibrary.PHASE_GOODBYE)) {
// testtaker is done with test. skip.
continue;
}
if(testtaker.getCurrentpanelid() == null) {
// testtaker is the profile testtaker
continue;
}
resumeableTesttakers.add(testtaker);
}
// sort them from least recent to latest
Collections.sort(resumeableTesttakers, new Comparator<Testtaker>() {
#Override
public int compare(Testtaker o1, Testtaker o2) {
// TODO Auto-generated method stub
//return 0;
return new CompareToBuilder()
.append(o1.getLasttouched(), o2.getLasttouched())
.toComparison();
}
});
if(resumeableTesttakers.size() == 0 && availiblePanels.size() > 0) {
// nobody is resumeable but there are panels left to take
// send them to the panel choice
// TODO: This is probably a misuse of Struts.
log_.info("No resumeable testtakers. Sending to panel select");
saveToken(request);
ActionForward myForward = (new ActionForward("/do/capstartpanel?capStartPanelAction=retest&lasttesttakerid="
+ testtakers.get(0).getTesttakerid(), true));
return myForward;// mapping.findForward(ConstantLibrary.FWD_CONTINUE + "-panel");
} else {
// grab the one most recently created and take their test
log_.info(String.format("Resuming with choice of %d testtakers", resumeableTesttakers.size()));
// we're forwarding to resume at this point, so we should do the some of the initialization
// that would have happened if we were still using getTesttaker() instead of getTesttakers() above.
session.setAttribute(ConstantLibrary.SESSION_LOGIN, login);
session.setAttribute(ConstantLibrary.SESSION_TESTTAKER, resumeableTesttakers.get(resumeableTesttakers.size()-1));
saveToken(request);
return mapping.findForward(ConstantLibrary.FWD_RESUME);
}
}
It's not a worth changing multiple returns to a single return statement per method. Actually, that will unnecessarily increase the burden of storing the result in a local variable and then making the return finally,
ActionForward result = null;
//scenario 1
result = ...
//scenario 2
result = ...
//scenario 3
result = ...
//finally
return result;
Hope this helps, but, it doesn't make much sense to me
As pointed out by others, having a single return statement does not necessarily make your code cleaner. However, in this case splitting up the method in smaller pieces probably makes the code more readable.
For example, this part:
// first check if token is set
if(!isTokenValid(request, true)) {
String errmsg="There was a problem with your login. Please close your browser then reopen it and try again. Make sure to click the Login button only ONCE.";
request.setAttribute("errormessage", errmsg);
saveToken(request);
return mapping.findForward(ConstantLibrary.FWD_CONTINUE);
}
// check the form for input errors
String errmsg = checkInput(form);
if (errmsg != null) {
request.setAttribute("errormessage", errmsg);
saveToken(request);
return mapping.findForward(ConstantLibrary.FWD_CONTINUE);
}
could be replaced by introducing two methods and using those to write:
If(tokenNotSet() || formHasErrors()){
return mapping.findForward(ConstantLibrary.FWD_CONTINUE);
}
By doing this on multiple places the structure of the algorithm becomes more clear, possibly giving you more insight in how this code could be refactored to adhere to your coding guidelines.
I would set a an action forward variable at the start of the method.
ActionForward actionForwardToReturn = null;
Then replace each of these two lines
return mapping.getInputForward();
return mapping.findForward(ConstantLibrary.FWD_CONTINUE);
with these two lines :
actionForwardToReturn = mapping.getInputForward()
actionForwardToReturn = mapping.findForward(ConstantLibrary.FWD_CONTINUE);
finally return the variable.
return actionForwardToReturn;
This shouldn't be too difficult :)
On a side note... (actually the orginal answer to the question) :
Multiple return statements can make it hard to debug code.
I personally would have just one action object that you return at the end of the method. The benefit of this, is that i can put a break point right on the return statement and look at exactly what that object is.
Any logging or other cross cutting concern I would want to add later, would only have to be done at one point. Otherwise I would have to add a log statement to every line where you are returning.
The complexity added to a method in an attempt to remove multiple return statements is many a times not worth it, especially in a method such as yours.There's nothing wrong with using them in this case.
Like user3580294 there's nothing wrong with multiple return statements. However you could combine the last two if statements since they are essentially returning the same thing.
Use #Octopus 's method if you absolutely have to have one return statement