Java code: Improve code quality & test coverage

wilayah-indonesia/.gitignore

@@ -1,4 +1,5 @@
 /.idea
 /resources/*
 /target
-maps.iml
+maps.iml
+*.iml

wilayah-indonesia/indonesia.iml

@@ -12,8 +12,10 @@
     <orderEntry type="sourceFolder" forTests="false" />
     <orderEntry type="library" scope="TEST" name="Maven: junit:junit:4.13.1" level="project" />
     <orderEntry type="library" scope="TEST" name="Maven: org.hamcrest:hamcrest-core:1.3" level="project" />
-    <orderEntry type="library" name="Maven: com.google.code.gson:gson:2.7" level="project" />
-    <orderEntry type="library" scope="PROVIDED" name="Maven: org.projectlombok:lombok:1.18.16" level="project" />
+    <orderEntry type="library" name="Maven: com.google.code.gson:gson:2.8.8" level="project" />
+    <orderEntry type="library" scope="PROVIDED" name="Maven: org.projectlombok:lombok:1.18.20" level="project" />
     <orderEntry type="library" name="Maven: log4j:log4j:1.2.17" level="project" />
+    <orderEntry type="library" name="Maven: org.slf4j:slf4j-api:1.7.12" level="project" />
+    <orderEntry type="library" scope="RUNTIME" name="Maven: org.slf4j:slf4j-log4j12:1.7.12" level="project" />
   </component>
 </module>

wilayah-indonesia/pom.xml

@@ -23,12 +23,12 @@
     <dependency>
       <groupId>com.google.code.gson</groupId>
       <artifactId>gson</artifactId>
-      <version>2.7</version>
+      <version>2.8.8</version>
     </dependency>
     <dependency>
       <groupId>org.projectlombok</groupId>
       <artifactId>lombok</artifactId>
-      <version>1.18.16</version>
+      <version>1.18.20</version>
       <scope>provided</scope>
     </dependency>
 
@@ -38,6 +38,17 @@
       <artifactId>log4j</artifactId>
       <version>1.2.17</version>
     </dependency>
+    <dependency>
+      <groupId>org.slf4j</groupId>
+      <artifactId>slf4j-api</artifactId>
+      <version>1.7.12</version>
+    </dependency>
+    <dependency>
+      <groupId>org.slf4j</groupId>
+      <artifactId>slf4j-log4j12</artifactId>
+      <version>1.7.12</version>
+      <scope>runtime</scope>
+    </dependency>
 
   </dependencies>
 </project>

wilayah-indonesia/src/main/java/wilayah/indonesia/Loader.java

@@ -1,32 +1,39 @@
 package wilayah.indonesia;
 
-import java.io.*;
-import org.apache.log4j.Logger;
+import java.io.BufferedInputStream;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import lombok.AccessLevel;
+import lombok.NoArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import lombok.var;
 
 /**
  * Created by yusuf on 24/10/16.
  */
+@Slf4j
+@NoArgsConstructor(access = AccessLevel.PRIVATE)
 public class Loader {
 
-    final static Logger logger = Logger.getLogger(Loader.class);
     /**
      * Load a file content to string using BufferedInputStream since it fast
-     * @param file
-     * @return
-     * @throws Exception
+     *
+     * @param file file path
+     * @return content string
+     * @throws IOException throws if failed to load the file
      */
-    public static String read(String file) throws Exception {
+    public static String read(String file) throws IOException {
         final long start = System.currentTimeMillis();
-        final InputStream in = new BufferedInputStream(new FileInputStream(file));
-        int bytesRead = 0;
-        String line = "";
-        final byte[] buf = new byte[50130];
-        while ((bytesRead = in.read(buf)) != -1) {
-            line += new String(buf, 0, bytesRead);
+        try (final InputStream in = new BufferedInputStream(new FileInputStream(file))) {
+            var bytesRead = 0;
+            var line = new StringBuilder();
+            final byte[] buf = new byte[50130];
+            while ((bytesRead = in.read(buf)) != -1) {
+                line.append(new String(buf, 0, bytesRead));
+            }
+            log.debug("Load {} took {} ms", file, (System.currentTimeMillis() - start));
+            return line.toString();
         }
-        in.close();
-
-        logger.debug("Load " + file + " took " + (System.currentTimeMillis() - start) + " ms");
-        return line;
     }
 }

wilayah-indonesia/src/main/java/wilayah/indonesia/Location.java

@@ -2,135 +2,138 @@
 
 import com.google.gson.Gson;
 import com.google.gson.reflect.TypeToken;
+import java.io.IOException;
+import java.lang.reflect.Type;
+import java.util.List;
+import java.util.stream.Collectors;
+import lombok.AccessLevel;
+import lombok.NoArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
 import wilayah.indonesia.model.District;
 import wilayah.indonesia.model.Province;
 import wilayah.indonesia.model.Regency;
 import wilayah.indonesia.model.Village;
-import org.apache.log4j.Logger;
-
-import java.lang.reflect.Type;
-import java.util.ArrayList;
-import java.util.List;
 
 /**
  * Created by yusuf on 24/10/16.
  */
+@Slf4j
+@NoArgsConstructor(access = AccessLevel.PRIVATE)
 public class Location {
 
     public enum TREE_LEVEL {
         PROVINCE, REGENCY, DISTRICT, VILLAGE
     }
 
-    final static Logger logger = Logger.getLogger(Location.class);
-
-    private static final Type PROVINCES = new TypeToken<List<Province>>() {}.getType();
-    private static final Type REGENCIES = new TypeToken<List<Regency>>() {}.getType();
-    private static final Type DISTRICT = new TypeToken<List<District>>() {}.getType();
-    private static final Type VILLAGE = new TypeToken<List<Village>>() {}.getType();
+    private static final String EMPTY_JSON = "[{}]";
+    private static final Type PROVINCES = TypeToken.getParameterized(List.class, Province.class)
+        .getType();
+    private static final Type REGENCIES = TypeToken.getParameterized(List.class, Regency.class)
+        .getType();
+    private static final Type DISTRICT = TypeToken.getParameterized(List.class, District.class)
+        .getType();
+    private static final Type VILLAGE = TypeToken.getParameterized(List.class, Village.class)
+        .getType();
 
     public static final Gson gson = new Gson();
+    public static final String PROVINCE_TREE_PATH = "./resources/list_of_area/indonesia-region.min.json";
+    public static final String PROVINCE_PATH = "./resources/list_of_area/provinces.json";
+    public static final String REGENCY_PATH = "./resources/list_of_area/regencies.json";
+    public static final String DISTRICT_PATH = "./resources/list_of_area/districts.json";
+    public static final String VILLAGE_PATH = "./resources/list_of_area/villages.json";
+
+    public static List<Province> provinces() throws IOException, LocationException {
+        return gson.fromJson(Loader.read(PROVINCE_PATH), PROVINCES);
+    }
 
-    public static List<Province> Provinces() throws Exception {
-        String provinces = Loader.read("./resources/list_of_area/provinces.json");
-        return gson.fromJson(provinces, PROVINCES);
+    @Deprecated
+    public static List<Province> Provinces() throws IOException, LocationException {
+        return provinces();
     }
 
-    public static List<Regency> Regencies() throws Exception {
-        String regencies = Loader.read("./resources/list_of_area/regencies.json");
-        return gson.fromJson(regencies, REGENCIES);
+    public static List<Regency> regencies() throws IOException, LocationException {
+        return gson.fromJson(Loader.read(REGENCY_PATH), REGENCIES);
     }
 
-    public static List<District> Districts() throws Exception {
-        String districts = Loader.read("./resources/list_of_area/districts.json");
-        return gson.fromJson(districts, DISTRICT);
+    @Deprecated
+    public static List<Regency> Regencies() throws IOException, LocationException {
+        return regencies();
     }
 
-    public static List<Village> Villages() throws Exception {
-        String villages = Loader.read("./resources/list_of_area/villages.json");
-        return gson.fromJson(villages, VILLAGE);
+    public static List<District> districts() throws IOException, LocationException {
+        return gson.fromJson(Loader.read(DISTRICT_PATH), DISTRICT);
     }
 
-    public static List<Province> ProvinceTrees() throws Exception {
-        String treeStr = Loader.read("./resources/list_of_area/indonesia-region.min.json");
-        List<Province> tree = gson.fromJson(treeStr, PROVINCES);
-        return tree;
+    @Deprecated
+    public static List<District> Districts() throws IOException, LocationException {
+        return districts();
     }
 
-    public static List<Province> ProvinceTrees(TREE_LEVEL tree_level) throws Exception {
-        String provincesStr = "[{}]";
-        String regenciesStr = "[{}]";
-        String districtsStr = "[{}]";
-        String villagesStr = "[{}]";
+    public static List<Village> villages() throws IOException, LocationException {
+        return gson.fromJson(Loader.read(VILLAGE_PATH), VILLAGE);
+    }
 
-        switch (tree_level) {
-            case PROVINCE:
-                provincesStr = Loader.read("./resources/list_of_area/provinces.json");
-                break;
+    @Deprecated
+    public static List<Village> Villages() throws IOException, LocationException {
+        return villages();
+    }
 
-            case REGENCY:
-                provincesStr = Loader.read("./resources/list_of_area/provinces.json");
-                regenciesStr = Loader.read("./resources/list_of_area/regencies.json");
-                break;
+    public static List<Province> provinceTrees() throws IOException, LocationException {
+        return gson.fromJson(Loader.read(PROVINCE_TREE_PATH), PROVINCES);
+    }
 
-            case DISTRICT:
-                provincesStr = Loader.read("./resources/list_of_area/provinces.json");
-                regenciesStr = Loader.read("./resources/list_of_area/regencies.json");
-                districtsStr = Loader.read("./resources/list_of_area/districts.json");
-                break;
+    public static List<Province> provinceTrees(final TREE_LEVEL treeLevel)
+        throws IOException, LocationException {
+
+        if (treeLevel == null) {
+            throw new LocationException();
+        }
+
+        final String provincesStr = Loader.read(PROVINCE_PATH);
+        String regenciesStr = EMPTY_JSON;
+        String districtsStr = EMPTY_JSON;
+        String villagesStr = EMPTY_JSON;
 
+        switch (treeLevel) {
             case VILLAGE:
-                provincesStr = Loader.read("./resources/list_of_area/provinces.json");
-                regenciesStr = Loader.read("./resources/list_of_area/regencies.json");
-                districtsStr = Loader.read("./resources/list_of_area/districts.json");
-                villagesStr  = Loader.read("./resources/list_of_area/villages.json");
+                villagesStr = Loader.read(VILLAGE_PATH);
+                // fallthrough
+            case DISTRICT:
+                districtsStr = Loader.read(DISTRICT_PATH);
+                // fallthrough
+            case REGENCY:
+                regenciesStr = Loader.read(REGENCY_PATH);
+                // fallthrough
+            case PROVINCE:
                 break;
 
-            default:
-                provincesStr = Loader.read("./resources/list_of_area/provinces.json");
-                break;
         }
 
-
         List<Province> provinces = gson.fromJson(provincesStr, PROVINCES);
         List<Regency> regencies = gson.fromJson(regenciesStr, REGENCIES);
         List<District> districts = gson.fromJson(districtsStr, DISTRICT);
         List<Village> villages = gson.fromJson(villagesStr, VILLAGE);
 
         final long start = System.currentTimeMillis();
-        List<Province> newProvinces = new ArrayList<>();
-        provinces.forEach(p -> {
-
-            List<Regency> newRegencies = new ArrayList<>();
-            regencies.forEach(r -> {
-                if(p.getId().equals( r.getProvince_id() )) {
-
-                    List<District> newDistricts = new ArrayList<>();
-                    districts.forEach(d -> {
-                        if(r.getId().equals( d.getRegency_id() )) {
-
-                            List<Village> newVillages = new ArrayList<>();
-                            villages.forEach(v -> {
-                                if(d.getId().equals( v.getDistrict_id() )) {
-                                    newVillages.add(v);
-                                }
-                            });
-
-                            d.setVillages(newVillages);
-                            newDistricts.add(d);
-                        }
-                    });
-
-                    r.setDistricts(newDistricts);
-                    newRegencies.add(r);
-                }
-            });
-
-            p.setRegencies(newRegencies);
-            newProvinces.add(p);
-        });
-
-        logger.debug("Mapping location tree dependency took " + (System.currentTimeMillis() - start) + " ms");
+
+        final List<Province> newProvinces = provinces.stream()
+            .map(province -> Utils.setChild(province, regencies, districts, villages))
+            .collect(Collectors.toList());
+
+        log.debug("Mapping location tree dependency took {} ms",
+            (System.currentTimeMillis() - start));
         return newProvinces;
     }
 
+    @Deprecated
+    public static List<Province> ProvinceTrees() throws IOException, LocationException {
+        return provinceTrees();
+    }
+
+    @Deprecated
+    public static List<Province> ProvinceTrees(final TREE_LEVEL treeLevel)
+        throws IOException, LocationException {
+        return provinceTrees(treeLevel);
+    }
+
 }

wilayah-indonesia/src/main/java/wilayah/indonesia/LocationException.java

@@ -0,0 +1,12 @@
+package wilayah.indonesia;
+
+
+import lombok.NoArgsConstructor;
+
+@NoArgsConstructor
+public class LocationException extends RuntimeException {
+
+    public LocationException(String message) {
+        super(message);
+    }
+}