[Change] Locker 增加清理日志;

[Add] LockerMapTest 增加单元测试;

src/main/java/net/lamgc/cgj/util/Locker.java

@@ -1,9 +1,14 @@
 package net.lamgc.cgj.util;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import java.util.concurrent.atomic.AtomicInteger;
 
 public final class Locker<K> {
 
+    private final static Logger log = LoggerFactory.getLogger(Locker.class);
+
     private final LockerMap<K> fromMap;
 
     private final K key;
@@ -56,9 +61,15 @@ public final class Locker<K> {
 
     @Override
     public String toString() {
-        return "Locker{" +
+        return "Locker@" + this.hashCode() + "{" +
                 "fromMap=" + fromMap +
                 ", key=" + key +
                 '}';
     }
+
+    @Override
+    protected void finalize() throws Throwable {
+        super.finalize();
+        log.trace("{} 已销毁.", this.toString());
+    }
 }