Spring Framework example source code file (CommonsDbcpNativeJdbcExtractor.java)

This example Spring Framework source code file (CommonsDbcpNativeJdbcExtractor.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Spring Framework tags/keywords

callablestatement, class, connection, connection, dbcp, jdbc, nativejdbcextractoradapter, object, object, preparedstatement, reflection, resultset, sql, sqlexception, sqlexception, statement, statement

The Spring Framework CommonsDbcpNativeJdbcExtractor.java source code

/*
 * Copyright 2002-2008 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 allow 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);
		}
	}


	protected Connection doGetNativeConnection(Connection con) throws SQLException {
		return (Connection) getInnermostDelegate(con);
	}

	public Statement getNativeStatement(Statement stmt) throws SQLException {
		return (Statement) getInnermostDelegate(stmt);
	}

	public PreparedStatement getNativePreparedStatement(PreparedStatement ps) throws SQLException {
		return (PreparedStatement) getNativeStatement(ps);
	}

	public CallableStatement getNativeCallableStatement(CallableStatement cs) throws SQLException {
		return (CallableStatement) getNativeStatement(cs);
	}

	public ResultSet getNativeResultSet(ResultSet rs) throws SQLException {
		return (ResultSet) getInnermostDelegate(rs);
	}

}