Support setting a custom ReLinkerInstance (e.g. to enable logging).

Author: greenrobot-team

objectbox-java/src/main/java/io/objectbox/BoxStore.java

@@ -59,8 +59,9 @@
 @ThreadSafe
 public class BoxStore implements Closeable {
 
-    /** Android Context used for native library loading. */
+    /** On Android used for native library loading. */
     @Nullable public static Object context;
+    @Nullable public static Object relinker;
 
     private static final String VERSION = "2.4.0-2019-01-08";
     private static BoxStore defaultStore;
@@ -190,6 +191,7 @@ public static boolean isObjectBrowserAvailable() {
 
     BoxStore(BoxStoreBuilder builder) {
         context = builder.context;
+        relinker = builder.relinker;
         NativeLibraryLoader.ensureLoaded();
 
         directory = builder.directory;

objectbox-java/src/main/java/io/objectbox/BoxStoreBuilder.java

@@ -66,9 +66,9 @@ public class BoxStoreBuilder {
     /** BoxStore uses this */
     File directory;
 
-    /** Android Context used for native library loading. */
-    @Nullable
-    Object context;
+    /** On Android used for native library loading. */
+    @Nullable Object context;
+    @Nullable Object relinker;
 
     /** Ignored by BoxStore */
     private File baseDirectory;
@@ -195,6 +195,18 @@ public BoxStoreBuilder androidContext(Object context) {
         return this;
     }
 
+    /**
+     * Pass a custom ReLinkerInstance, for example {@code ReLinker.log(logger)} to use for loading the native library
+     * on Android devices. Note that setting {@link #androidContext(Object)} is required for ReLinker to work.
+     */
+    public BoxStoreBuilder androidReLinker(Object reLinkerInstance) {
+        if (reLinkerInstance == null) {
+            throw new NullPointerException("ReLinkerInstance may not be null");
+        }
+        this.relinker = reLinkerInstance;
+        return this;
+    }
+
     static File getAndroidDbDir(Object context, @Nullable String dbName) {
         File baseDir = getAndroidBaseDir(context);
         return new File(baseDir, dbName(dbName));

objectbox-java/src/main/java/io/objectbox/internal/NativeLibraryLoader.java

@@ -131,11 +131,16 @@ private static boolean loadLibraryAndroid(String libname) {
 
         try {
             Class<?> context = Class.forName("android.content.Context");
-            Class<?> relinker = Class.forName("com.getkeepsafe.relinker.ReLinker");
-            // ReLinker.loadLibrary(Context context, String library)
-            Method loadLibrary = relinker.getMethod("loadLibrary", context, String.class);
-
-            loadLibrary.invoke(null, BoxStore.context, libname);
+            if (BoxStore.relinker == null) {
+                // use default ReLinker
+                Class<?> relinker = Class.forName("com.getkeepsafe.relinker.ReLinker");
+                Method loadLibrary = relinker.getMethod("loadLibrary", context, String.class);
+                loadLibrary.invoke(null, BoxStore.context, libname);
+            } else {
+                // use custom ReLinkerInstance
+                Method loadLibrary = BoxStore.relinker.getClass().getMethod("loadLibrary", context, String.class);
+                loadLibrary.invoke(BoxStore.relinker, BoxStore.context, libname);
+            }
         } catch (ReflectiveOperationException e) {
             // note: do not catch Exception as it will swallow ReLinker exceptions useful for debugging
             return false;