add license description.

src/test/java/com/alibaba/druid/TestRollBack.java

@@ -1,3 +1,18 @@
+/*
+ * Copyright 1999-2011 Alibaba Group Holding Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 package com.alibaba.druid;
 
 import java.beans.PropertyVetoException;
@@ -71,14 +86,14 @@ public class TestRollBack {
 
 	@Before
 	public void before() {
-		// 清空所有数据
+		// 清空æ‰?œ‰æ•°æ�®
 		dao_c3p0.clear("msg");
 	}
 
 	@Test
 	public void test_c3p0() {
 		try {
-			// 将两条插入语句包裹在一个事务内执行,第一条可以正常插入,第二条超过字段长度,会抛异常,事务会回滚
+			// 将两æ�¡æ�’入语å�¥åŒ…裹在ä¸?¸ªäº‹åŠ¡å†…执è¡?第一æ�¡å�¯ä»¥æ­£å¸¸æ�’å…?第二æ�¡è¶…过字段长åº?会抛异常,事务会回æ»?
 			Trans.exec(new Atom() {
 				@Override
 				public void run() {
@@ -89,7 +104,7 @@ public class TestRollBack {
 		} catch (Exception e) {
 		    
 		}
-		// abc也跟着回滚了
+		// abc也跟ç�?›žæ»šäº†
 		Assert.assertNull(dao_c3p0.fetch("msg", Cnd.where("message", "=", "abc")));
 	}