Added possibility to define number of days for forecast. Code refactoring.

pom.xml

@@ -8,6 +8,19 @@
     <artifactId>by.prominence.openweater.api</artifactId>
     <version>1.0-SNAPSHOT</version>
 
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <source>8</source>
+                    <target>8</target>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
     <dependencies>
         <dependency>
             <groupId>com.alibaba</groupId>

src/main/java/by/prominence/openweather/api/OpenWeatherProviderManager.java

@@ -24,7 +24,6 @@ package by.prominence.openweather.api;
 
 import by.prominence.openweather.api.provider.ForecastProvider;
 import by.prominence.openweather.api.provider.WeatherProvider;
-import by.prominence.openweather.api.provider.OpenWeatherProvider;
 
 public class OpenWeatherProviderManager {
 
@@ -34,11 +33,16 @@ public class OpenWeatherProviderManager {
         this.authToken = token;
     }
 
-    public OpenWeatherProvider getWeather() {
+    public WeatherProvider getWeather() {
         return new WeatherProvider(authToken);
     }
-    public OpenWeatherProvider getForecast() {
+
+    public ForecastProvider getForecast() {
         return new ForecastProvider(authToken);
     }
 
+    public ForecastProvider getForecast(int amountOfDays) {
+        return new ForecastProvider(authToken, amountOfDays);
+    }
+
 }

src/main/java/by/prominence/openweather/api/exception/InvalidAuthTokenException.java

@@ -25,7 +25,7 @@ package by.prominence.openweather.api.exception;
 public class InvalidAuthTokenException extends Exception {
 
     public InvalidAuthTokenException() {
-        super("Please, check you authentication token! You can get it here: https://home.openweathermap.org/api_keys/.");
+        super("Check you authentication token! You can get it here: https://home.openweathermap.org/api_keys/. Please, notice that some requests requires non-free subscription plan.");
     }
 
     public InvalidAuthTokenException(String message) {

src/main/java/by/prominence/openweather/api/provider/AbstractOpenWeatherProvider.java

@@ -29,9 +29,12 @@ import by.prominence.openweather.api.model.Coordinates;
 import by.prominence.openweather.api.model.OpenWeatherResponse;
 import by.prominence.openweather.api.utils.JsonUtils;
 
+import java.io.IOException;
 import java.lang.reflect.ParameterizedType;
 import java.net.HttpURLConnection;
+import java.net.MalformedURLException;
 import java.net.URL;
+import java.util.Map;
 
 public abstract class AbstractOpenWeatherProvider<T extends OpenWeatherResponse> implements OpenWeatherProvider {
 
@@ -82,53 +85,71 @@ public abstract class AbstractOpenWeatherProvider<T extends OpenWeatherResponse>
         return executeRequest("?zip=" + zipCode + "," + countryCode);
     }
 
-    protected T executeRequest(String parameterString) throws InvalidAuthTokenException, DataNotFoundException {
+    protected T executeRequest(String requestSpecificParameters) throws InvalidAuthTokenException, DataNotFoundException {
-
-        String url = getRequestUrl() + parameterString + "&appid=" + authToken;
-
-        if (language != null) {
-            url += "&lang=" + language;
-        }
-
-        if (unit != null) {
-            url += "&units=" + unit;
-        }
-
-        if (accuracy != null) {
-            url += "&type=" + accuracy;
-        }
 
         T openWeatherResponse = null;
 
         try {
-            URL requestUrl = new URL(url);
+            URL requestUrl = buildURL(requestSpecificParameters);
 
             HttpURLConnection connection = (HttpURLConnection) requestUrl.openConnection();
             connection.setRequestMethod("GET");
 
-            if (connection.getResponseCode() == HttpURLConnection.HTTP_OK) {
+            switch (connection.getResponseCode()) {
-                openWeatherResponse = type.cast(JsonUtils.parseJson(connection.getInputStream(), type));
+                case HttpURLConnection.HTTP_OK:
-
+                    openWeatherResponse = type.cast(JsonUtils.parseJson(connection.getInputStream(), type));
-                if (openWeatherResponse.getResponseCode() == 401) {
+                    break;
+                case HttpURLConnection.HTTP_UNAUTHORIZED:
                     throw new InvalidAuthTokenException();
-                }
+                case HttpURLConnection.HTTP_NOT_FOUND:
-
-                if (openWeatherResponse.getResponseCode() == 404) {
                     throw new DataNotFoundException();
-                }
-            } else {
-                throw new DataNotFoundException();
             }
-        } catch (Exception ex) {
+        } catch (IOException | ClassCastException ex) {
             ex.printStackTrace();
         }
 
         return openWeatherResponse;
     }
 
-    private String getRequestUrl() {
+    protected String getRequestUrl() {
         return System.OPEN_WEATHER_API_URL + getRequestType();
     }
 
+    protected Map<String, String> getAdditionalParameters() {
+        return null;
+    }
+
+    private URL buildURL(String requestSpecificParameters) throws MalformedURLException {
+
+        StringBuilder urlBuilder = new StringBuilder(getRequestUrl() + requestSpecificParameters + "&appid=" + authToken);
+
+        if (language != null) {
+            urlBuilder.append("&lang=");
+            urlBuilder.append(language);
+        }
+
+        if (unit != null) {
+            urlBuilder.append("&units=");
+            urlBuilder.append(unit);
+        }
+
+        if (accuracy != null) {
+            urlBuilder.append("&type=");
+            urlBuilder.append(accuracy);
+        }
+
+        Map<String, String> additionalParameters = getAdditionalParameters();
+        if (additionalParameters != null) {
+            additionalParameters.forEach((key, value) -> {
+                urlBuilder.append("&");
+                urlBuilder.append(key);
+                urlBuilder.append("=");
+                urlBuilder.append(value);
+            });
+        }
+
+        return new URL(urlBuilder.toString());
+    }
+
     protected abstract String getRequestType();
 }

src/main/java/by/prominence/openweather/api/provider/ForecastProvider.java

@@ -24,13 +24,37 @@ package by.prominence.openweather.api.provider;
 
 import by.prominence.openweather.api.model.forecast.ForecastResponse;
 
+import java.util.HashMap;
+import java.util.Map;
+
 public class ForecastProvider extends AbstractOpenWeatherProvider<ForecastResponse> {
 
+    private int amountOfDays = -1;
+
     public ForecastProvider(String authToken) {
         super(authToken);
     }
 
+    public ForecastProvider(String authToken, int amountOfDays) {
+        super(authToken);
+        this.amountOfDays = amountOfDays;
+    }
+
     protected String getRequestType() {
+        if (amountOfDays != -1) {
+            return "forecast/daily";
+        }
         return "forecast";
     }
+
+    @Override
+    protected Map<String, String> getAdditionalParameters() {
+        Map<String, String> additionalParameters = null;
+        if (amountOfDays != -1) {
+            additionalParameters = new HashMap<>();
+            additionalParameters.put("cnt", String.valueOf(amountOfDays));
+        }
+
+        return additionalParameters;
+    }
 }