/*
* Copyright 2002-2010 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.lob;
import java.io.InputStream;
import java.io.Reader;
import java.sql.PreparedStatement;
import java.sql.SQLException;
/**
* Interface that abstracts potentially database-specific creation of large binary
* fields and large text fields. Does not work with <code>java.sql.Blob</code>
* and <code>java.sql.Clob</code> instances in the API, as some JDBC drivers
* do not support these types as such.
*
* <p>The LOB creation part is where {@link LobHandler} implementations usually
* differ. Possible strategies include usage of
* <code>PreparedStatement.setBinaryStream/setCharacterStream</code> but also
* <code>PreparedStatement.setBlob/setClob</code> with either a stream argument
* (requires JDBC 4.0) or <code>java.sql.Blob/Clob</code> wrapper objects.
*
* <p>A LobCreator represents a session for creating BLOBs: It is <i>not</i>
* thread-safe and needs to be instantiated for each statement execution or for
* each transaction. Each LobCreator needs to be closed after completion.
*
* <p>For convenient working with a PreparedStatement and a LobCreator,
* consider using {@link org.springframework.jdbc.core.JdbcTemplate} with an
*{@link org.springframework.jdbc.core.support.AbstractLobCreatingPreparedStatementCallback}
* implementation. See the latter's javadoc for details.
*
* @author Juergen Hoeller
* @since 04.12.2003
* @see #close()
* @see LobHandler#getLobCreator()
* @see DefaultLobHandler.DefaultLobCreator
* @see OracleLobHandler.OracleLobCreator
* @see java.sql.PreparedStatement#setBlob
* @see java.sql.PreparedStatement#setClob
* @see java.sql.PreparedStatement#setBytes
* @see java.sql.PreparedStatement#setBinaryStream
* @see java.sql.PreparedStatement#setString
* @see java.sql.PreparedStatement#setAsciiStream
* @see java.sql.PreparedStatement#setCharacterStream
*/
public interface LobCreator {
/**
* Set the given content as bytes on the given statement, using the given
* parameter index. Might simply invoke <code>PreparedStatement.setBytes</code>
* or create a Blob instance for it, depending on the database and driver.
* @param ps the PreparedStatement to the set the content on
* @param paramIndex the parameter index to use
* @param content the content as byte array, or <code>null</code> for SQL NULL
* @throws SQLException if thrown by JDBC methods
* @see java.sql.PreparedStatement#setBytes
*/
void setBlobAsBytes(PreparedStatement ps, int paramIndex, byte[] content)
throws SQLException;
/**
* Set the given content as binary stream on the given statement, using the given
* parameter index. Might simply invoke <code>PreparedStatement.setBinaryStream</code>
* or create a Blob instance for it, depending on the database and driver.
* @param ps the PreparedStatement to the set the content on
* @param paramIndex the parameter index to use
* @param contentStream the content as binary stream, or <code>null</code> for SQL NULL
* @throws SQLException if thrown by JDBC methods
* @see java.sql.PreparedStatement#setBinaryStream
*/
void setBlobAsBinaryStream(
PreparedStatement ps, int paramIndex, InputStream contentStream, int contentLength)
throws SQLException;
/**
* Set the given content as String on the given statement, using the given
* parameter index. Might simply invoke <code>PreparedStatement.setString</code>
* or create a Clob instance for it, depending on the database and driver.
* @param ps the PreparedStatement to the set the content on
* @param paramIndex the parameter index to use
* @param content the content as String, or <code>null</code> for SQL NULL
* @throws SQLException if thrown by JDBC methods
* @see java.sql.PreparedStatement#setBytes
*/
void setClobAsString(PreparedStatement ps, int paramIndex, String content)
throws SQLException;
/**
* Set the given content as ASCII stream on the given statement, using the given
* parameter index. Might simply invoke <code>PreparedStatement.setAsciiStream</code>
* or create a Clob instance for it, depending on the database and driver.
* @param ps the PreparedStatement to the set the content on
* @param paramIndex the parameter index to use
* @param asciiStream the content as ASCII stream, or <code>null</code> for SQL NULL
* @throws SQLException if thrown by JDBC methods
* @see java.sql.PreparedStatement#setAsciiStream
*/
void setClobAsAsciiStream(
PreparedStatement ps, int paramIndex, InputStream asciiStream, int contentLength)
throws SQLException;
/**
* Set the given content as character stream on the given statement, using the given
* parameter index. Might simply invoke <code>PreparedStatement.setCharacterStream</code>
* or create a Clob instance for it, depending on the database and driver.
* @param ps the PreparedStatement to the set the content on
* @param paramIndex the parameter index to use
* @param characterStream the content as character stream, or <code>null</code> for SQL NULL
* @throws SQLException if thrown by JDBC methods
* @see java.sql.PreparedStatement#setCharacterStream
*/
void setClobAsCharacterStream(
PreparedStatement ps, int paramIndex, Reader characterStream, int contentLength)
throws SQLException;
/**
* Close this LobCreator session and free its temporarily created BLOBs and CLOBs.
* Will not need to do anything if using PreparedStatement's standard methods,
* but might be necessary to free database resources if using proprietary means.
* <p><b>NOTE</b>: Needs to be invoked after the involved PreparedStatements have
* been executed or the affected O/R mapping sessions have been flushed.
* Otherwise, the database resources for the temporary BLOBs might stay allocated.
*/
void close();
}
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