DEC-4839 druid没有写默认的ms连接前校验语句，hibernate也没加，最后导致出错

fine-druid/src/com/fr/third/alibaba/druid/pool/vendor/MSSQLValidConnectionChecker.java

@@ -1,59 +1,54 @@
-/*
- * Copyright 1999-2017 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.
- */
+//
+// Source code recreated from a .class file by IntelliJ IDEA
+// (powered by Fernflower decompiler)
+//
+
 package com.fr.third.alibaba.druid.pool.vendor;
 
+import com.fr.third.alibaba.druid.pool.ValidConnectionChecker;
+import com.fr.third.alibaba.druid.pool.ValidConnectionCheckerAdapter;
+import com.fr.third.alibaba.druid.util.JdbcUtils;
+
 import java.io.Serializable;
 import java.sql.Connection;
 import java.sql.SQLException;
 import java.sql.Statement;
 
-import com.fr.third.alibaba.druid.pool.ValidConnectionChecker;
-import com.fr.third.alibaba.druid.pool.ValidConnectionCheckerAdapter;
-import com.fr.third.alibaba.druid.util.JdbcUtils;
-
-/**
- * A MSSQLValidConnectionChecker.
- */
 public class MSSQLValidConnectionChecker extends ValidConnectionCheckerAdapter implements ValidConnectionChecker, Serializable {
-
+    
     private static final long serialVersionUID = 1L;
-
-    public MSSQLValidConnectionChecker(){
-
+    
+    public MSSQLValidConnectionChecker() {
+    
     }
-
-    public boolean isValidConnection(final Connection c, String validateQuery, int validationQueryTimeout) throws Exception {
+    
+    public boolean isValidConnection(Connection c, String validateQuery, int validationQueryTimeout) throws Exception {
+        
+        if (validateQuery == null || validateQuery.isEmpty()) {
+            validateQuery = "select 1";
+        }
+        
         if (c.isClosed()) {
             return false;
-        }
-
-        Statement stmt = null;
-
-        try {
-            stmt = c.createStatement();
-            if (validationQueryTimeout > 0) {
-                stmt.setQueryTimeout(validationQueryTimeout);
+        } else {
+            Statement stmt = null;
+            
+            boolean var5;
+            try {
+                stmt = c.createStatement();
+                if (validationQueryTimeout > 0) {
+                    stmt.setQueryTimeout(validationQueryTimeout);
+                }
+                
+                stmt.execute(validateQuery);
+                var5 = true;
+            } catch (SQLException var9) {
+                throw var9;
+            } finally {
+                JdbcUtils.close(stmt);
             }
-            stmt.execute(validateQuery);
-            return true;
-        } catch (SQLException e) {
-            throw e;
-        } finally {
-            JdbcUtils.close(stmt);
+            
+            return var5;
         }
     }
-
 }