add testcase & remove unused code

src/main/java/com/alibaba/druid/util/JdbcSqlStatUtils.java

@@ -18,22 +18,24 @@ package com.alibaba.druid.util;
 import java.lang.reflect.Method;
 import java.util.Arrays;
 import java.util.Map;
+import java.util.concurrent.atomic.AtomicIntegerFieldUpdater;
+import java.util.concurrent.atomic.AtomicLongFieldUpdater;
 
 import com.alibaba.druid.stat.JdbcSqlStat;
 import com.alibaba.druid.support.logging.Log;
 import com.alibaba.druid.support.logging.LogFactory;
 
-
 public class JdbcSqlStatUtils {
+
     private final static Log LOG = LogFactory.getLog(JdbcSqlStatUtils.class);
-    
+
     @SuppressWarnings("unchecked")
     public static Map<String, Object> getData(Object jdbcSqlStat) {
         try {
             if (jdbcSqlStat.getClass() == JdbcSqlStat.class) {
                 return ((JdbcSqlStat) jdbcSqlStat).getData();
             }
-            
+
             Method method = jdbcSqlStat.getClass().getMethod("getData");
             Object obj = method.invoke(jdbcSqlStat);
             return (Map<String, Object>) obj;
@@ -42,7 +44,7 @@ public class JdbcSqlStatUtils {
             return null;
         }
     }
-    
+
     public static long[] rtrim(long[] array) {
         int notZeroLen = array.length;
         for (int i = array.length - 1; i >= 0; --i, notZeroLen--) {
@@ -50,11 +52,27 @@ public class JdbcSqlStatUtils {
                 break;
             }
         }
-        
+
         if (notZeroLen != array.length) {
             array = Arrays.copyOf(array, notZeroLen);
         }
-        
+
         return array;
     }
+
+    public static <T> int get(T stat, AtomicIntegerFieldUpdater<T> updater, boolean reset) {
+        if (reset) {
+            return updater.getAndSet(stat, 0);
+        } else {
+            return updater.get(stat);
+        }
+    }
+
+    public static <T> long get(T stat, AtomicLongFieldUpdater<T> updater, boolean reset) {
+        if (reset) {
+            return updater.getAndSet(stat, 0);
+        } else {
+            return updater.get(stat);
+        }
+    }
 }