001: /*
002: * Copyright 2002-2006 the original author or authors.
003: *
004: * Licensed under the Apache License, Version 2.0 (the "License");
005: * you may not use this file except in compliance with the License.
006: * You may obtain a copy of the License at
007: *
008: * http://www.apache.org/licenses/LICENSE-2.0
009: *
010: * Unless required by applicable law or agreed to in writing, software
011: * distributed under the License is distributed on an "AS IS" BASIS,
012: * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013: * See the License for the specific language governing permissions and
014: * limitations under the License.
015: */
016:
017: package org.springframework.jdbc.support.nativejdbc;
018:
019: import java.sql.Connection;
020: import java.sql.SQLException;
021:
022: import org.apache.commons.logging.Log;
023: import org.apache.commons.logging.LogFactory;
024:
025: /**
026: * Simple implementation of the NativeJdbcExtractor interface.
027: * Assumes a pool that wraps Connection handles but not DatabaseMetaData:
028: * In this case, the underlying native Connection can be retrieved by simply
029: * calling <code>conHandle.getMetaData().getConnection()</code>.
030: * All other JDBC objects will be returned as passed in.
031: *
032: * <p>This extractor should work with any pool that does not wrap DatabaseMetaData,
033: * and will also work with any plain JDBC driver. Note that a pool can still wrap
034: * Statements, PreparedStatements, etc: The only requirement of this extractor is
035: * that <code>java.sql.DatabaseMetaData</code> does not get wrapped, returning the
036: * native Connection of the JDBC driver on <code>metaData.getConnection()</code>.
037: *
038: * <p>Customize this extractor by setting the "nativeConnectionNecessaryForXxx"
039: * flags accordingly: If Statements, PreparedStatements, and/or CallableStatements
040: * are wrapped by your pool, set the corresponding "nativeConnectionNecessaryForXxx"
041: * flags to "true". If none of the statement types is wrapped - or you solely need
042: * Connection unwrapping in the first place -, the defaults are fine.
043: *
044: * <p>SimpleNativeJdbcExtractor is a common choice for use with OracleLobHandler,
045: * which just needs Connection unwrapping via the
046: * <code>getNativeConnectionFromStatement</code> method. This usage will work
047: * with almost any connection pool. Known to work are, for example:
048: * <ul>
049: * <li>Caucho Resin 2.1.x, 3.0.x
050: * <li>Sun Java System Application Server 8
051: * <li>Oracle OC4J 9.0.3, 9.0.4
052: * <li>C3P0 0.8.x
053: * <li>Jakarta Commons DBCP 1.0, 1.1, 1.2 (used in Tomcat 4.1.x, 5.0.x)
054: * <li>JBoss 3.2.x
055: * </ul>
056: *
057: * <p>For full usage with JdbcTemplate, i.e. to also provide Statement unwrapping:
058: * <ul>
059: * <li>Use a default SimpleNativeJdbcExtractor for Resin and SJSAS (no JDBC
060: * Statement objects are wrapped, therefore no special unwrapping is necessary).
061: * <li>Use a SimpleNativeJdbcExtractor with all "nativeConnectionNecessaryForXxx"
062: * flags set to "true" for OC4J and C3P0 (all JDBC Statement objects are wrapped,
063: * but none of the wrappers allow for unwrapping).
064: * <li>Use a CommonsDbcpNativeJdbcExtractor for Jakarta Commons DBCP respectively
065: * a JBossNativeJdbcExtractor for JBoss (all JDBC Statement objects are wrapped,
066: * but all of them can be extracted by casting to implementation classes).
067: * </ul>
068: *
069: * @author Juergen Hoeller
070: * @since 05.12.2003
071: * @see java.sql.DatabaseMetaData#getConnection
072: * @see #getNativeConnection
073: * @see #setNativeConnectionNecessaryForNativeStatements
074: * @see #setNativeConnectionNecessaryForNativePreparedStatements
075: * @see #setNativeConnectionNecessaryForNativeCallableStatements
076: * @see CommonsDbcpNativeJdbcExtractor
077: * @see JBossNativeJdbcExtractor
078: * @see org.springframework.jdbc.core.JdbcTemplate#setNativeJdbcExtractor
079: * @see org.springframework.jdbc.support.lob.OracleLobHandler#setNativeJdbcExtractor
080: */
081: public class SimpleNativeJdbcExtractor extends
082: NativeJdbcExtractorAdapter {
083:
084: private boolean nativeConnectionNecessaryForNativeStatements = false;
085:
086: private boolean nativeConnectionNecessaryForNativePreparedStatements = false;
087:
088: private boolean nativeConnectionNecessaryForNativeCallableStatements = false;
089:
090: /**
091: * Set whether it is necessary to work on the native Connection to
092: * receive native Statements. Default is "false". If true, the Connection
093: * will be unwrapped first to create a Statement.
094: * <p>This makes sense if you need to work with native Statements from
095: * a pool that does not allow to extract the native JDBC objects from its
096: * wrappers but returns the native Connection on DatabaseMetaData.getConnection.
097: * <p>The standard SimpleNativeJdbcExtractor is unable to unwrap statements,
098: * so set this to true if your connection pool wraps Statements.
099: * @see java.sql.Connection#createStatement
100: * @see java.sql.DatabaseMetaData#getConnection
101: */
102: public void setNativeConnectionNecessaryForNativeStatements(
103: boolean nativeConnectionNecessaryForNativeStatements) {
104: this .nativeConnectionNecessaryForNativeStatements = nativeConnectionNecessaryForNativeStatements;
105: }
106:
107: public boolean isNativeConnectionNecessaryForNativeStatements() {
108: return nativeConnectionNecessaryForNativeStatements;
109: }
110:
111: /**
112: * Set whether it is necessary to work on the native Connection to
113: * receive native PreparedStatements. Default is "false". If true,
114: * the Connection will be unwrapped first to create a PreparedStatement.
115: * <p>This makes sense if you need to work with native PreparedStatements from
116: * a pool that does not allow to extract the native JDBC objects from its
117: * wrappers but returns the native Connection on Statement.getConnection.
118: * <p>The standard SimpleNativeJdbcExtractor is unable to unwrap statements,
119: * so set this to true if your connection pool wraps PreparedStatements.
120: * @see java.sql.Connection#prepareStatement
121: * @see java.sql.DatabaseMetaData#getConnection
122: */
123: public void setNativeConnectionNecessaryForNativePreparedStatements(
124: boolean nativeConnectionNecessary) {
125: this .nativeConnectionNecessaryForNativePreparedStatements = nativeConnectionNecessary;
126: }
127:
128: public boolean isNativeConnectionNecessaryForNativePreparedStatements() {
129: return nativeConnectionNecessaryForNativePreparedStatements;
130: }
131:
132: /**
133: * Set whether it is necessary to work on the native Connection to
134: * receive native CallableStatements. Default is "false". If true,
135: * the Connection will be unwrapped first to create a CallableStatement.
136: * <p>This makes sense if you need to work with native CallableStatements from
137: * a pool that does not allow to extract the native JDBC objects from its
138: * wrappers but returns the native Connection on Statement.getConnection.
139: * <p>The standard SimpleNativeJdbcExtractor is unable to unwrap statements,
140: * so set this to true if your connection pool wraps CallableStatements.
141: * @see java.sql.Connection#prepareCall
142: * @see java.sql.DatabaseMetaData#getConnection
143: */
144: public void setNativeConnectionNecessaryForNativeCallableStatements(
145: boolean nativeConnectionNecessary) {
146: this .nativeConnectionNecessaryForNativeCallableStatements = nativeConnectionNecessary;
147: }
148:
149: public boolean isNativeConnectionNecessaryForNativeCallableStatements() {
150: return nativeConnectionNecessaryForNativeCallableStatements;
151: }
152:
153: }
|