Issue 6364 - Exclude double initialization of AdblockHelper

libadblockplus-android-settings/src/org/adblockplus/libadblockplus/android/settings/AdblockHelper.java

Index: libadblockplus-android-settings/src/org/adblockplus/libadblockplus/android/settings/AdblockHelper.java
diff --git a/libadblockplus-android-settings/src/org/adblockplus/libadblockplus/android/settings/AdblockHelper.java b/libadblockplus-android-settings/src/org/adblockplus/libadblockplus/android/settings/AdblockHelper.java
index 476d150bb22538d44542130d2e3eadb487170e83..7ecd94c3a8726efb9a6b82332d23c932b49560d2 100644
--- a/libadblockplus-android-settings/src/org/adblockplus/libadblockplus/android/settings/AdblockHelper.java
+++ b/libadblockplus-android-settings/src/org/adblockplus/libadblockplus/android/settings/AdblockHelper.java
@@ -45,6 +45,7 @@ public class AdblockHelper
   public static final String PRELOAD_PREFERENCE_NAME = "ADBLOCK_PRELOAD";
   private static AdblockHelper _instance;
 
+  private boolean isInitialized;
   private SingleInstanceEngineProvider provider;
   private AdblockSettingsStorage storage;
 
@@ -141,11 +142,25 @@ public class AdblockHelper
   public SingleInstanceEngineProvider init(Context context, String basePath,
                                            boolean developmentBuild, String preferenceName)
   {
+    if (isInitialized)
+    {
+      new IllegalStateException("Usage exception: already initialized. Check `isInit()`");
+    }
+
     initProvider(context, basePath, developmentBuild);
     initStorage(context, preferenceName);
+    isInitialized = true;
     return provider;
   }
 
+  /**
+   * Check if it is already initialized
+   * @return
+   */
+  public boolean isInit() {

[jens, 2018/02/07 09:36:25]

for consistency I would probably call this method isInitialized()

[anton, 2018/02/07 09:52:55]

initialize method is called `init()` to i've names it `isInit()`.
It's undesired to rename `init()` method as it break back compatibility.

[jens, 2018/02/07 10:03:23]

Okay, I don't insist to change it. 
But it's kind of inconsistent to me that the boolean is called isInitialized and
the method is called isInit().

+    return isInitialized;
+  }
+
   private void initProvider(Context context, String basePath, boolean developmentBuild)
   {
     provider = new SingleInstanceEngineProvider(context, basePath, developmentBuild);