Provide a java method to release native memory

Calling close allows java code to release the native memory
associated with the bluetooth object.
This provides control over the allocated memory, without the need to
wait for the finalize method to be invoked by the JVM.

Signed-off-by: Tzafrir Poupko <[email protected]>

Author: Tzafrir Poupko

java/BluetoothObject.java

@@ -26,9 +26,10 @@
 
 import java.util.*;
 
-public abstract class BluetoothObject implements Cloneable
+public abstract class BluetoothObject implements Cloneable,AutoCloseable
 {
     protected long nativeInstance;
+    private boolean isValid;
 
     static {
         try {
@@ -57,11 +58,12 @@ public abstract class BluetoothObject implements Cloneable
     protected BluetoothObject(long instance)
     {
         nativeInstance = instance;
+        isValid = true;
     }
 
     protected void finalize()
     {
-        delete();
+        close();
     }
 
     public boolean equals(Object obj)
@@ -77,4 +79,16 @@ public int hashCode() {
         String objectPath = getObjectPath();
         return objectPath.hashCode();
     }
+
+    /**
+     * Release the native memory associated with this object
+     * The object should not be used following a call to close
+     */
+    @Override
+    public synchronized void close() {
+        if (!isValid)
+            return;
+        isValid = false;
+        delete();
+    }
 }