Align APIs: align server change listener with client.

Author: greenrobot-team

objectbox-java/src/main/java/io/objectbox/sync/server/SyncServer.java

@@ -1,11 +1,13 @@
 package io.objectbox.sync.server;
 
+import java.io.Closeable;
+
+import javax.annotation.Nullable;
+
 import io.objectbox.annotation.apihint.Experimental;
 import io.objectbox.sync.Sync;
 import io.objectbox.sync.listener.SyncChangeListener;
 
-import java.io.Closeable;
-
 /**
  * ObjectBox sync server. Build a server with {@link Sync#server}.
  */
@@ -35,13 +37,9 @@ public interface SyncServer extends Closeable {
 
     /**
      * Sets a {@link SyncChangeListener}. Replaces a previously set listener.
+     * Set to {@code null} to remove the listener.
      */
-    void setSyncChangesListener(SyncChangeListener listener);
-
-    /**
-     * Removes a previously set {@link SyncChangeListener}. Does nothing if no listener was set.
-     */
-    void removeSyncChangesListener();
+    void setSyncChangeListener(@Nullable SyncChangeListener listener);
 
     /**
      * Starts the server (e.g. bind to port) and gets everything operational.

objectbox-java/src/main/java/io/objectbox/sync/server/SyncServerBuilder.java

@@ -22,7 +22,7 @@ public class SyncServerBuilder {
     final List<PeerInfo> peers = new ArrayList<>();
 
     @Nullable String certificatePath;
-    SyncChangeListener changesListener;
+    SyncChangeListener changeListener;
 
     public SyncServerBuilder(BoxStore boxStore, String url, SyncCredentials authenticatorCredentials) {
         checkNotNull(boxStore, "BoxStore is required.");
@@ -53,12 +53,12 @@ public SyncServerBuilder authenticatorCredentials(SyncCredentials authenticatorC
 
     /**
      * Sets a listener to observe fine granular changes happening during sync.
-     * This listener can also be set (or removed) on the sync client directly.
-     *
-     * @see SyncServer#setSyncChangesListener(SyncChangeListener)
+     * <p>
+     * This listener can also be {@link SyncServer#setSyncChangeListener(SyncChangeListener) set or removed}
+     * on the Sync server directly.
      */
-    public SyncServerBuilder changesListener(SyncChangeListener changesListener) {
-        this.changesListener = changesListener;
+    public SyncServerBuilder changeListener(SyncChangeListener changeListener) {
+        this.changeListener = changeListener;
         return this;
     }
 

objectbox-java/src/main/java/io/objectbox/sync/server/SyncServerImpl.java

@@ -41,8 +41,8 @@ public class SyncServerImpl implements SyncServer {
             nativeAddPeer(handle, peer.url, credentialsInternal.getTypeId(), credentialsInternal.getTokenBytes());
         }
 
-        if (builder.changesListener != null) {
-            setSyncChangesListener(builder.changesListener);
+        if (builder.changeListener != null) {
+            setSyncChangeListener(builder.changeListener);
         }
     }
 
@@ -67,18 +67,11 @@ public String getStatsString() {
     }
 
     @Override
-    public void setSyncChangesListener(SyncChangeListener changesListener) {
-        checkNotNull(changesListener, "Listener must not be null. Use removeSyncChangesListener to remove existing listener.");
+    public void setSyncChangeListener(@Nullable SyncChangeListener changesListener) {
         this.syncChangeListener = changesListener;
         nativeSetSyncChangesListener(handle, changesListener);
     }
 
-    @Override
-    public void removeSyncChangesListener() {
-        this.syncChangeListener = null;
-        nativeSetSyncChangesListener(handle, null);
-    }
-
     @Override
     public void start() {
         nativeStart(handle);
@@ -108,12 +101,6 @@ protected void finalize() throws Throwable {
         super.finalize();
     }
 
-    private void checkNotNull(Object object, String message) {
-        if (object == null) {
-            throw new IllegalArgumentException(message);
-        }
-    }
-
     private static native long nativeCreate(long storeHandle, String uri, @Nullable String certificatePath);
 
     private native void nativeDelete(long handle);