Why objects are to be created in calling some functions - java

In the Geocoder.java class there is the below method
public List<Address> getFromLocation(double latitude, double longitude, int maxResults)
throws IOException {
if (latitude < -90.0 || latitude > 90.0) {
throw new IllegalArgumentException("latitude == " + latitude);
}
if (longitude < -180.0 || longitude > 180.0) {
throw new IllegalArgumentException("longitude == " + longitude);
}
try {
List<Address> results = new ArrayList<Address>();
String ex = mService.getFromLocation(latitude, longitude, maxResults,
mParams, results);
if (ex != null) {
throw new IOException(ex);
} else {
return results;
}
} catch (RemoteException e) {
Log.e(TAG, "getFromLocation: got RemoteException", e);
return null;
}
}
Here getFromLocation is the member function of the class. So to call this function can't we simply call that as List<Address> address = Geocoder.getFromLocation(//the required parameters). I know this won't work and to make it work we need to create an object of Geocoder class. So can anyone please explain why the object creation is necessary, I am bit confused as I had seen in some cases functions are called by directly using their class names

Related

How to refactor this If/else statement in a try/catch block?

I was wondering if there is a better way to code this piece of code:
private void getLatitudeAndLongitudeFromZipcode() {
String zipcode = mSharedPreferences.getString("Zipcode", "");
try {
List<Address> address = geocoder.getFromLocationName(zipcode, 1);
if ((address != null ? address.size() : 0) > 0) {
Address first = address.get(0);
mLatitude = first.getLatitude();
mLongitude = first.getLongitude();
mCurrentLocationName = getLocationAsName();
mSharedPreferences.edit().putLong("oldLat", Double.doubleToRawLongBits(mLatitude))
.apply();
mSharedPreferences.edit().putLong("oldLong", Double.doubleToRawLongBits(mLongitude))
.apply();
} else {
getOldZipcodeLocation();//duplicate method call
}
} catch (IOException e) {
getOldZipcodeLocation();//duplicate method call
e.printStackTrace();
}
}
Basic idea is that if they don't have internet and an exception is thrown, I want to get the old coordinates from storage. However, I also want to get the old coordinates if they are currently in a place that doesn't give them coordinates. For example, if the geocoder returns null. What bothers me is the duplicate method call in the else block and catch block. Any way to make this code cleaner? I'll take any other tips as well!
Yes you can , 1st get address through IOException separately , then use address in your if..else statement . that's it .
private void getLatitudeAndLongitudeFromZipcode() {
String zipcode = mSharedPreferences.getString("Zipcode", "");
List<Address> address = null;
try {
address = new Geocoder(this).getFromLocationName(zipcode, 1);
} catch (IOException e) {
e.printStackTrace();
}
if ((address != null ? address.size() : 0) > 0) {
Address first = address.get(0);
mLatitude = first.getLatitude();
mLongitude = first.getLongitude();
mCurrentLocationName = getLocationAsName();
mSharedPreferences.edit().putLong("oldLat", Double.doubleToRawLongBits(mLatitude))
.apply();
mSharedPreferences.edit().putLong("oldLong", Double.doubleToRawLongBits(mLongitude))
.apply();
} else {
getOldZipcodeLocation();
}
}

IndexOutOfBoundsException on List<Address>

In my Android app I have this code:
LatLng[] branches;
String[] branchesArray = HomeActivity.branches.toArray(new String[HomeActivity.branches.size()]);
for (int i = 0; i < HomeActivity.branches.size(); i++) {
branches[i] = getLocationFromAddress(branchesArray[i]);
}
getLocationFromAddress method:
public LatLng getLocationFromAddress(String strAddress) {
Geocoder coder = new Geocoder(this);
List<Address> address;
LatLng p1 = null;
try {
address = coder.getFromLocationName(strAddress, 1);
if (address == null) {
return null;
}
Address location = address.get(0);
location.getLatitude();
location.getLongitude();
p1 = new LatLng((double) (location.getLatitude()), (double) (location.getLongitude()));
} catch (IOException e) {
Log.e("Error", e.getMessage());
}
return p1;
}
This code supposed to create an array of LatLng, extracted from an array of string addresses. The problem is that whenever I'm running this code, I get java.lang.IndexOutOfBoundsException: Invalid index 0, size is 0 in the log. It refers to line 137 as the problematic line, which is this line:
Address location = address.get(0);
How can I fix that?
The probleme is you are forgetting to initialize "branches" variable with the correct size that's why your are getting "size 0 index 0"
String[] branches = HomeActivity.branches.toArray(new String[HomeActivity.branches.size()]);
getLocationFromName documentation says:
returns a list of Address objects. Returns null or empty list if no
matches were found or there is no backend service available.
In your case it is returning an empty list, so you should add an additional check:
public LatLng getLocationFromAddress(String strAddress) {
Geocoder coder = new Geocoder(this);
List<Address> address;
LatLng p1 = null;
try {
address = coder.getFromLocationName(strAddress, 1);
if (address == null || address.isEmpty()) {
return null;
}
Address location = address.get(0);
p1 = new LatLng(location.getLatitude(), location.getLongitude());
} catch (IOException e) {
Log.e("Error", e.getMessage());
}
return p1;
}

Error management

I use spring boot in a rest architecture.
I'm a newbee with error management.
My code have this structure
#Transactional
#Override
public void processPayment() throws CreditCardPaymentException{
List<Payment> payments = paymentRepository.findByDateLessThanEqualAndPaymentModeAndStatus(LocalDate.now(), PaymentModeEnum.CREDITCARD, StatusEnum.STANDBY);
processCreditCardPayment(payments);
}
private void processCreditCardPayment(List<Payment> payments) throws ProcessPaymentException{
PaymentGatewayConfig paymentGateway = new PaymentGatewayConfig();
String crypt_type = "7";
for (Payment payment : payments) {
chargeMemberCreditCard(payment, crypt_type, paymentGateway);
}
}
private ResolverReceipt chargeMemberCreditCard(Payment payment, String crypt_type, PaymentGatewayConfig paymentGateway) throws ProcessPaymentException {
try {
if (resreceipt != null) {
//information about customer we have sent are returned
ResolveData resdata = resreceipt.getResolveData();
//todo check auth code
if (Boolean.valueOf(resreceipt.getComplete()) && !Boolean.valueOf(resreceipt.getTimedOut())) {
//if (resreceipt != null && resreceipt.getResponseCode() != null && Integer.getInteger(resreceipt.getResponseCode()) < 50) {
payment.setStatus(StatusEnum.COMPLETE);
} else {
payment.setStatus(StatusEnum.FAIL);
}
}
} catch (Exception e) {
throw new ProcessPaymentException();
log.error("chargeMemberCreditCard - payment: " + payment.getPaymentId(), e);
}
}
If there is an error in a payment, I want to pass to the next one.
If there are many error at the end, I just want to know there are err who happen.
No sure if it's the way to go and if this code will do that.
accumulate your failed Payments or Exceptions in processCreditCardPayment
private void processCreditCardPayment(List<Payment> payments) throws ProcessPaymentException{
PaymentGatewayConfig paymentGateway = new PaymentGatewayConfig();
String crypt_type = "7";
List<Payment> failedPayments = new ArrayList<Payments>();
for (Payment payment : payments) {
try {
chargeMemberCreditCard(payment, crypt_type, paymentGateway);
} catch (ProcessPaymentException ppe) {
filedPayments.add(payment);
// or you can accumulate excetions instead of Payments
}
}
// create some higher level exception with failed Payent collection and throw it, or log it.

Why result size of getFromLocation() is 0 ? How to get address from geopoint ? - Android

I want to return a string array from Async class back to the activity that is calling this asynchronous class that is job is to do the reverse geocoding.
So, from my activity I call the constructor of the class like this:
Double[] lat_long = new Double[] { Double.parseDouble(map_lat), Double.parseDouble(map_long) };
ReverseGeocodingTask reverseGeocoding = new ReverseGeocodingTask(getActivity().getApplicationContext());
reverseGeocoding.execute(lat_long);
And this is the code of the class:
class ReverseGeocodingTask extends AsyncTask<Double, Void, List<String>> {
public static List<String> LIST = new ArrayList<String>();
Context mContext;
public ReverseGeocodingTask(Context context) {
super();
mContext = context;
}
#Override
protected List<String> doInBackground(Double... params) {
Geocoder gc= new Geocoder(mContext, Locale.getDefault());
List<Address> addrList = null;
double latitude = params[0].doubleValue();
double longitude = params[1].doubleValue();
Log.d("LATLONG", latitude + ":" + longitude);
try {
addrList = gc.getFromLocation(latitude, longitude, 1);
if (addrList.size() > 0) {
//format location info
Address address = addrList.get(0);
LIST.add(address.getLocality());
LIST.add(address.getSubAdminArea());
LIST.add(address.getCountryName());
Log.d("LIST", LIST.get(0));
}
else{
Log.d("addrList SIZE", "=0");
return null;
}
} catch (IOException e) {
e.printStackTrace();
return null;
}
return LIST;
}
#Override
protected void onPostExecute(List<String> result) {
if (result != null) {
Log.d("ON POST", result.get(0));
}
}
}
This is the logcat:
02-28 19:20:04.323 12275-14109/guide_me_for_all.guide_me_for_all D/LATLONG﹕ 34.681377999999995:33.039339
02-28 19:20:05.434 12275-14109/guide_me_for_all.guide_me_for_all D/addrList SIZE﹕ =0
I get correctly the latitude and longitude point as you can see from the Log.d(), BUT getFromLocation.size() is always 0.
This may be a problem with your GeoCoder service. If you're backend service for the device is not present or has other problems, you will get this response.
use isPresent to check if an implementation is present.
Also, see this post here:
Geocoder.getFromLocation throws IOException on Android emulator
And the docs mention that you need a backend service:
http://developer.android.com/reference/android/location/Geocoder.html

Constructing the most reliable user country mechanism

In an application that I'm currently working on there is a huge need to determine user country as fast as possible and as reliable as possible. I have decided to rely on three ways for finding user country; each one has its advantages and disadvantages:
Android inner methods to get the SIM country.
GeoCoding.
IP to Location API.
Here are the three pieces of code:
1. Android inner methods to get the SIM country:
public static String getUserCountry(Context context) {
try {
final TelephonyManager tm = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);
final String simCountry = tm.getSimCountryIso();
if (simCountry != null && simCountry.length() == 2) { // SIM country code is available
CupsLog.d(TAG, "getUserCountry, simCountry: " + simCountry.toLowerCase(Locale.US));
return simCountry.toLowerCase(Locale.US);
}
else if (tm.getPhoneType() != TelephonyManager.PHONE_TYPE_CDMA) { // device is not 3G (would be unreliable)
String networkCountry = tm.getNetworkCountryIso();
if (networkCountry != null && networkCountry.length() == 2) { // network country code is available
CupsLog.d(TAG, "getUserCountry, networkCountry: " + networkCountry.toLowerCase(Locale.US));
return networkCountry.toLowerCase(Locale.US);
}
}
}
catch (Exception e) { }
return null;
}
2. GeoCoding:
public static void getCountryCode(final Location location, final Context context) {
CupsLog.d(TAG, "getCountryCode");
AsyncTask<Void, Void, String> countryCodeTask = new AsyncTask<Void, Void, String>() {
final float latitude = (float) location.getLatitude();
final float longitude = (float) location.getLongitude();
List<Address> addresses = null;
Geocoder gcd = new Geocoder(context);
String code = null;
#Override
protected String doInBackground(Void... params) {
CupsLog.d(TAG, "doInBackground");
try {
addresses = gcd.getFromLocation(latitude, longitude, 10);
for (int i=0; i < addresses.size(); i++)
{
if (addresses.get(i) != null && addresses.get(i).getCountryCode() != null)
{
code = addresses.get(i).getCountryCode();
}
}
} catch (IOException e) {
CupsLog.d(TAG, "IOException" + e);
}
return code;
}
#Override
protected void onPostExecute(String code)
{
if (code != null)
{
CupsLog.d(TAG, "getCountryCode :" + code.toLowerCase());
UserLocation.instance.setCountryCode(code.toLowerCase());
CookieUtil.formatLangueageAndLocationCookie();
CookieUtil.instance.instantateCookieUtil(context);
}
}
};
if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.GINGERBREAD_MR1) {
CupsLog.d(TAG, "countryCodeTask.execute();");
countryCodeTask.execute();
} else {
CupsLog.d(TAG, "countryCodeTask.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);");
countryCodeTask.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
}
}
3. IP to Location API:
private void getUserCountryByIp() {
AsyncHttpClient client = new AsyncHttpClient();
client.setCookieStore(CookieUtil.instance.getPersistentCookieStore());
String userCountryApi = "http://ip-api.com/json";
CupsLog.i(TAG, "country uri: " + userCountryApi);
client.get(userCountryApi, new JsonHttpResponseHandler() {
#Override
public void onSuccess(JSONObject orderResponseJSON) {
CupsLog.i(TAG, "onSuccess(JSONObject res)");
try
{
CupsLog.i(TAG, "JsonResponse: "+ orderResponseJSON.toString(3));
String tempString = orderResponseJSON.getString("countryCode");
if (tempString != null)
{
//countryCodeFromIpApi = tempString.toLowerCase();
UserLocation.instance.setCountryCode(tempString.toLowerCase());
CookieUtil.formatLangueageAndLocationCookie();
CookieUtil.instance.instantateCookieUtil(LoginActivity.this);
isGotCountryFromIp = true;
}
} catch (JSONException e) {
CupsLog.i(TAG, "JSONException: " + e);
}
}
#Override
public void onFailure(Throwable arg0, JSONObject orderResponseJSON) {
CupsLog.i(TAG, "onFailure");
try {
CupsLog.i(TAG, "JsonResponse: "+ orderResponseJSON.toString(3));
} catch (JSONException e) {
CupsLog.i(TAG, "JSONException: " + e);
}
}
#Override
public void onFinish() {
CupsLog.i(TAG, "onFinish");
super.onFinish();
}
});
}
Now I have those 3 methods that are working great, my problem is more of a Java problem. The first method give me the result right away, while the two others (2,3) are potentiality long running tasks. what more is that the first option is the most not reliable one, as users can travel to different countries with the SIM card. The second is more reliable but still sometimes does not returns an country (depending on the location of the user). The third one is the one that I found to be the most reliable one, but the most long as well.
The question: knowing this information, how would I construct a method that uses those 3 methods in the right order for reliability stand point and considering the long running tasks factor?
Unfortunately there is no really reliable way to determine the physical location of a user (e.g. his/her cellphone) because:
SIM card might be bought and/or manufactured in other country;
Geocoding (which is AFAIU based on GPS/GLONASS coordinates) might give wrong (~10m) results or no results at all if user disabled it or no satellites are visible (underground, for example);
Resolving country by IP might also give you wrong results, for example because of using VPN;
So my advice would be to ask user, which country he is currently in and willing to "tell" you so.

Categories

Resources