content: /*
   * Copyright (c) 2002, 2020, Oracle and/or its affiliates.
   *
   * This program is free software; you can redistribute it and/or modify it under
   * the terms of the GNU General Public License, version 2.0, as published by the
   * Free Software Foundation.
   *
   * This program is also distributed with certain software (including but not
   * limited to OpenSSL) that is licensed under separate terms, as designated in a
   * particular file or component or in included license documentation. The
   * authors of MySQL hereby grant you an additional permission to link the
   * program and your derivative works with the separately licensed software that
   * they have included with MySQL.
   *
   * Without limiting anything contained in the foregoing, this file, which is
   * part of MySQL Connector/J, is also subject to the Universal FOSS Exception,
   * version 1.0, a copy of which can be found at
   * http://oss.oracle.com/licenses/universal-foss-exception.
   *
   * This program is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
   * FOR A PARTICULAR PURPOSE. See the GNU General Public License, version 2.0,
   * for more details.
   *
   * You should have received a copy of the GNU General Public License along with
   * this program; if not, write to the Free Software Foundation, Inc.,
   * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
   */
  
  package com.mysql.cj.jdbc;
  
  import java.lang.reflect.InvocationHandler;
  import java.lang.reflect.InvocationTargetException;
  import java.lang.reflect.Method;
  import java.lang.reflect.Proxy;
  import java.sql.SQLException;
  import java.util.Map;
  
  import com.mysql.cj.exceptions.ExceptionInterceptor;
  import com.mysql.cj.exceptions.MysqlErrorNumbers;
  import com.mysql.cj.util.Util;
  
  /**
   * Base class for all wrapped instances created by LogicalHandle
   */
  abstract class WrapperBase {
      protected MysqlPooledConnection pooledConnection;
  
      /**
       * Fires connection error event if required, before re-throwing exception
       * 
       * @param sqlEx
       *            the SQLException that has occurred
       * @throws SQLException
       *             (rethrown)
       */
      protected void checkAndFireConnectionError(SQLException sqlEx) throws SQLException {
          if (this.pooledConnection != null) {
              if (MysqlErrorNumbers.SQL_STATE_COMMUNICATION_LINK_FAILURE.equals(sqlEx.getSQLState())) {
                  this.pooledConnection.callConnectionEventListeners(MysqlPooledConnection.CONNECTION_ERROR_EVENT, sqlEx);
              }
          }
  
          throw sqlEx;
      }
  
      protected Map<Class<?>, Object> unwrappedInterfaces = null;
      protected ExceptionInterceptor exceptionInterceptor;
  
      protected WrapperBase(MysqlPooledConnection pooledConnection) {
          this.pooledConnection = pooledConnection;
          this.exceptionInterceptor = this.pooledConnection.getExceptionInterceptor();
      }
  
      protected class ConnectionErrorFiringInvocationHandler implements InvocationHandler {
          Object invokeOn = null;
  
          public ConnectionErrorFiringInvocationHandler(Object toInvokeOn) {
              this.invokeOn = toInvokeOn;
          }
  
          public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
              if ("equals".equals(method.getName())) {
                  // Let args[0] "unwrap" to its InvocationHandler if it is a proxy.
                  return args[0].equals(this);
              }
  
              Object result = null;
  
              try {
                  result = method.invoke(this.invokeOn, args);
  
                  if (result != null) {
                      result = proxyIfInterfaceIsJdbc(result, result.getClass());
                  }
              } catch (InvocationTargetException e) {
                  if (e.getTargetException() instanceof SQLException) {
                      checkAndFireConnectionError((SQLException) e.getTargetException());
                  } else {
                      throw e;
                  }
              }
  
              return result;
          }
  
          /**
           * Recursively checks for interfaces on the given object to determine
           * if it implements a java.sql interface, and if so, proxies the
           * instance so that we can catch and fire SQL errors.
           * 
           * @param toProxy
           *            object to be proxied
           * @param clazz
           *            desired class
           * @return proxy object
           */
          private Object proxyIfInterfaceIsJdbc(Object toProxy, Class<?> clazz) {
              Class<?>[] interfaces = clazz.getInterfaces();
  
              for (Class<?> iclass : interfaces) {
                  String packageName = Util.getPackageName(iclass);
  
                  if ("java.sql".equals(packageName) || "javax.sql".equals(packageName)) {
                      return Proxy.newProxyInstance(toProxy.getClass().getClassLoader(), interfaces, new ConnectionErrorFiringInvocationHandler(toProxy));
                  }
  
                  return proxyIfInterfaceIsJdbc(toProxy, iclass);
              }
  
              return toProxy;
          }
      }
  }
  