Address more sonar issues in drools-pdp

Addressed the following sonar issues:
- use of "synchronized"
- use Files.delete() instead of File.delete()

Issue-ID: POLICY-2305
Change-Id: Id55628fe12d9d764616e57321382a70cb5704ba1
Signed-off-by: Jim Hahn <jrh3@att.com>

1 files changed, 8 insertions, 6 deletions

diff --git a/policy-core/src/main/java/org/onap/policy/drools/core/lock/LockImpl.java b/policy-core/src/main/java/org/onap/policy/drools/core/lock/LockImpl.java
index 9596dbe8..8866eb82 100644
--- a/policy-core/src/main/java/org/onap/policy/drools/core/lock/LockImpl.java
+++ b/policy-core/src/main/java/org/onap/policy/drools/core/lock/LockImpl.java
@@ -100,13 +100,15 @@ public class LockImpl implements Lock, Serializable {
      * This method always succeeds, unless the lock is already unavailable.
      */
     @Override
-    public synchronized boolean free() {
-        if (isUnavailable()) {
-            return false;
-        }
+    public boolean free() {
+        synchronized (this) {
+            if (isUnavailable()) {
+                return false;
+            }
 
-        logger.info("releasing lock: {}", this);
-        setState(LockState.UNAVAILABLE);
+            logger.info("releasing lock: {}", this);
+            setState(LockState.UNAVAILABLE);
+        }
 
         return true;
     }