Java tutorial
/* * Copyright 2002-2012 the original author or authors. * * 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 org.springframework.jdbc.support.nativejdbc; import java.lang.reflect.Method; import java.lang.reflect.Modifier; import java.sql.CallableStatement; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import org.springframework.util.ReflectionUtils; /** * Implementation of the {@link NativeJdbcExtractor} interface for the * Jakarta Commons DBCP connection pool, version 1.1 or higher. * * <p>Returns the underlying native Connection, Statement, etc to application * code instead of DBCP's wrapper implementations. The returned JDBC classes * can then safely be cast, e.g. to {@code oracle.jdbc.OracleConnection}. * * <p>This NativeJdbcExtractor can be set just to <i>allow</i> working with a * Commons DBCP DataSource: If a given object is not a Commons DBCP wrapper, * it will be returned as-is. * * <p>Note that this version of CommonsDbcpNativeJdbcExtractor will work * against the original Commons DBCP in {@code org.apache.commons.dbcp} * as well as against Tomcat 5.5's relocated Commons DBCP version in the * {@code org.apache.tomcat.dbcp.dbcp} package. * * @author Juergen Hoeller * @since 25.08.2003 */ public class CommonsDbcpNativeJdbcExtractor extends NativeJdbcExtractorAdapter { private static final String GET_INNERMOST_DELEGATE_METHOD_NAME = "getInnermostDelegate"; /** * Extracts the innermost delegate from the given Commons DBCP object. * Falls back to the given object if no underlying object found. * @param obj the Commons DBCP Connection/Statement/ResultSet * @return the underlying native Connection/Statement/ResultSet */ private static Object getInnermostDelegate(Object obj) throws SQLException { if (obj == null) { return null; } try { Class<?> classToAnalyze = obj.getClass(); while (!Modifier.isPublic(classToAnalyze.getModifiers())) { classToAnalyze = classToAnalyze.getSuperclass(); if (classToAnalyze == null) { // No public provider class found -> fall back to given object. return obj; } } Method getInnermostDelegate = classToAnalyze.getMethod(GET_INNERMOST_DELEGATE_METHOD_NAME, (Class[]) null); Object delegate = ReflectionUtils.invokeJdbcMethod(getInnermostDelegate, obj); return (delegate != null ? delegate : obj); } catch (NoSuchMethodException ex) { return obj; } catch (SecurityException ex) { throw new IllegalStateException("Commons DBCP getInnermostDelegate method is not accessible: " + ex); } } @Override protected Connection doGetNativeConnection(Connection con) throws SQLException { return (Connection) getInnermostDelegate(con); } @Override public Statement getNativeStatement(Statement stmt) throws SQLException { return (Statement) getInnermostDelegate(stmt); } @Override public PreparedStatement getNativePreparedStatement(PreparedStatement ps) throws SQLException { return (PreparedStatement) getNativeStatement(ps); } @Override public CallableStatement getNativeCallableStatement(CallableStatement cs) throws SQLException { return (CallableStatement) getNativeStatement(cs); } @Override public ResultSet getNativeResultSet(ResultSet rs) throws SQLException { return (ResultSet) getInnermostDelegate(rs); } }