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.WrapperProxy;
  
  import java.sql.Connection;
  import java.sql.SQLException;
  import java.sql.Wrapper;
  
  /**
   * @author wenshao [szujobs@hotmail.com]
   */
  public class PoolableWrapper implements Wrapper {
      private final Wrapper wrapper;
  
      public PoolableWrapper(Wrapper wraaper) {
          this.wrapper = wraaper;
      }
  
      @Override
      public boolean isWrapperFor(Class<?> iface) throws SQLException {
          if (null == wrapper) {
              //Best to log error.
              return false;
          }
  
          if (iface == null) {
              return false;
          }
  
          if (wrapper instanceof DruidStatementConnection) {
              if (iface.isInstance(((DruidStatementConnection) wrapper).getConnection())) {
                  return true;
              }
          }
  
          if (iface == wrapper.getClass()) {
              return true;
          }
  
          if (iface == this.getClass()) {
              return true;
          }
  
          if (!(wrapper instanceof WrapperProxy)) {
              if (iface.isInstance(wrapper)) {
                  return true;
              }
          }
  
          return wrapper.isWrapperFor(iface);
      }
  
      @SuppressWarnings("unchecked")
      @Override
      public <T> T unwrap(Class<T> iface) throws SQLException {
          if (null == wrapper) {
              //Best to log error.
              return null;
          }
  
          if (iface == null) {
              return null;
          }
  
          if (wrapper instanceof DruidStatementConnection) {
              Connection conn = ((DruidStatementConnection) wrapper).getConnection();
              if (iface.isAssignableFrom(conn.getClass())) {
                  return (T) conn;
              }
          }
  
          if (iface == wrapper.getClass()) {
              return (T) wrapper;
          }
  
          if (iface == this.getClass()) {
              return (T) this;
          }
  
          if (!(wrapper instanceof WrapperProxy)) {
              if (iface.isInstance(wrapper)) {
                  return (T) wrapper;
              }
          }
  
          return wrapper.unwrap(iface);
      }
  
  }
  