Implement getLanguage() to get the ZIM file language code

kiwix.c

@@ -99,6 +99,23 @@ JNIEXPORT jstring JNICALL Java_org_kiwix_kiwixmobile_JNIKiwix_getId(JNIEnv *env,
   return id;
 }
 
+JNIEXPORT jstring JNICALL Java_org_kiwix_kiwixmobile_JNIKiwix_getLanguage(JNIEnv *env, jobject obj) {
+  jstring language;
+  
+  pthread_mutex_lock(&readerLock);
+  if (reader != NULL) {
+    try {
+      std::string cLanguage = reader->getLanguage();
+      language = c2jni(cLanguage, env);
+    } catch (exception &e) {
+      std::cerr << e.what() << std::endl;
+    }
+  }
+  pthread_mutex_unlock(&readerLock);
+  
+  return language;
+}
+
 JNIEXPORT jstring JNICALL Java_org_kiwix_kiwixmobile_JNIKiwix_getMimeType(JNIEnv *env, jobject obj, jstring url) {
   jstring mimeType;
   

src/org/kiwix/kiwixmobile/JNIKiwix.java

@@ -22,6 +22,7 @@ package org.kiwix.kiwixmobile;
 public class JNIKiwix {
     public native String getMainPage();
     public native String getId();
+    public native String getLanguage();
     public native String getMimeType(String url);
     public native boolean loadZIM(String path);
     public native byte[] getContent(String url, JNIKiwixString mimeType, JNIKiwixInt size);
@@ -30,7 +31,6 @@ public class JNIKiwix {
     public native boolean getPageUrlFromTitle(String title, JNIKiwixString url);
     public native boolean getTitle(JNIKiwixString title);
     public native boolean getDescription(JNIKiwixString title);
-    public native boolean getLanguage(JNIKiwixString language);
     public native boolean getDate(JNIKiwixString language);
     public native boolean getFavicon(JNIKiwixString content, JNIKiwixString mimeType);
     public native boolean getCreator(JNIKiwixString creator);

src/org/kiwix/kiwixmobile/ZimContentProvider.java

@@ -92,6 +92,14 @@ public class ZimContentProvider extends ContentProvider {
         }
     }
 
+    public static String getLanguage() {
+        if (jniKiwix == null || zimFileName == null) {
+            return null;
+        } else {
+            return jniKiwix.getLanguage();
+        }
+    }
+
     public static boolean searchSuggestions(String prefix, int count) {
         if (jniKiwix == null || zimFileName == null) {
             return false;