content: /*
   * Copyright 1999-2018 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.pool;
  
  import com.alibaba.druid.proxy.jdbc.ConnectionProxyImpl;
  import com.alibaba.druid.util.JdbcUtils;
  import com.alibaba.druid.util.StringUtils;
  
  import java.sql.Connection;
  import java.sql.ResultSet;
  import java.sql.Statement;
  import java.util.Properties;
  
  /**
   * @author wenshao [szujobs@hotmail.com]
   * @since 0.2.21
   */
  public class ValidConnectionCheckerAdapter implements ValidConnectionChecker {
      @Override
      public boolean isValidConnection(Connection conn, String query, int validationQueryTimeout) throws Exception {
          if (StringUtils.isEmpty(query)) {
              return true;
          }
          return execValidQuery(conn, query, validationQueryTimeout);
      }
  
      public static boolean execValidQuery(Connection conn, String query, int validationQueryTimeout) throws Exception {
          // using raw connection for createStatement to speed up validation by skipping all filters.
          Connection rawConn;
          if (conn instanceof DruidPooledConnection) {
              conn = ((DruidPooledConnection) conn).getConnection();
          }
          if (conn instanceof ConnectionProxyImpl) {
              rawConn = ((ConnectionProxyImpl) conn).getConnectionRaw();
          } else {
              rawConn = conn;
          }
  
          Statement stmt = null;
          boolean isDruidStatementConnection;
          if (rawConn instanceof DruidStatementConnection) {
              stmt = ((DruidStatementConnection) rawConn).getStatement();
              isDruidStatementConnection = true;
          } else {
              isDruidStatementConnection = false;
          }
          ResultSet rs = null;
          try {
              if (!isDruidStatementConnection) {
                  stmt = rawConn.createStatement();
              }
              if (validationQueryTimeout > 0) {
                  stmt.setQueryTimeout(validationQueryTimeout);
              }
              rs = stmt.executeQuery(query);
              return rs.next();
          } finally {
              JdbcUtils.close(rs);
              if (!isDruidStatementConnection) {
                  JdbcUtils.close(stmt);
              }
          }
      }
  
      @Override
      public void configFromProperties(Properties properties) {
      }
  
  }
  