Spring Framework

org.springframework.jdbc.support.lob
Class DefaultLobHandler

java.lang.Object
  extended by org.springframework.jdbc.support.lob.AbstractLobHandler
      extended by org.springframework.jdbc.support.lob.DefaultLobHandler
All Implemented Interfaces:
LobHandler

public class DefaultLobHandler
extends AbstractLobHandler

Default implementation of the LobHandler interface. Invokes the direct accessor methods that java.sql.ResultSet and java.sql.PreparedStatement offer.

This LobHandler should work for any JDBC driver that is JDBC compliant in terms of the spec's suggestions regarding simple BLOB and CLOB handling. This does not apply to Oracle 9i, and only to a limited degree to Oracle 10g! As a consequence, use OracleLobHandler for accessing Oracle BLOBs/CLOBs.

Some JDBC drivers require values with a BLOB/CLOB target column to be explicitly set through the JDBC setBlob / setClob API: for example, PostgreSQL's driver. Switch the "wrapAsLob" property to "true" when operating against such a driver.

On JDBC 4.0, this LobHandler also supports streaming the BLOB/CLOB content via the setBlob / setClob variants that take a stream argument directly. Consider switching the "streamAsLob" property to "true" when operating against a fully compliant JDBC 4.0 driver.

See the LobHandler javadoc for a summary of recommendations.

Since:
04.12.2003
Author:
Juergen Hoeller
See Also:
setStreamAsLob(boolean), ResultSet.getBytes(int), ResultSet.getBinaryStream(int), ResultSet.getString(int), ResultSet.getAsciiStream(int), ResultSet.getCharacterStream(int), PreparedStatement.setBytes(int, byte[]), PreparedStatement.setBinaryStream(int, java.io.InputStream, int), PreparedStatement.setString(int, java.lang.String), PreparedStatement.setAsciiStream(int, java.io.InputStream, int), PreparedStatement.setCharacterStream(int, java.io.Reader, int)

Nested Class Summary
protected  class DefaultLobHandler.DefaultLobCreator
          Default LobCreator implementation as inner class.
 
Field Summary
protected  org.apache.commons.logging.Log logger
           
 
Constructor Summary
DefaultLobHandler()
           
 
Method Summary
 java.io.InputStream getBlobAsBinaryStream(java.sql.ResultSet rs, int columnIndex)
          Retrieve the given column as binary stream from the given ResultSet.
 byte[] getBlobAsBytes(java.sql.ResultSet rs, int columnIndex)
          Retrieve the given column as bytes from the given ResultSet.
 java.io.InputStream getClobAsAsciiStream(java.sql.ResultSet rs, int columnIndex)
          Retrieve the given column as ASCII stream from the given ResultSet.
 java.io.Reader getClobAsCharacterStream(java.sql.ResultSet rs, int columnIndex)
          Retrieve the given column as character stream from the given ResultSet.
 java.lang.String getClobAsString(java.sql.ResultSet rs, int columnIndex)
          Retrieve the given column as String from the given ResultSet.
 LobCreator getLobCreator()
          Create a new LobCreator instance, i.e.
 void setStreamAsLob(boolean streamAsLob)
          Specify whether to submit a binary stream / character stream to the JDBC driver as explicit LOB content, using the JDBC 4.0 setBlob / setClob method with a stream argument.
 void setWrapAsLob(boolean wrapAsLob)
          Specify whether to submit a byte array / String to the JDBC driver wrapped in a JDBC Blob / Clob object, using the JDBC setBlob / setClob method with a Blob / Clob argument.
 
Methods inherited from class org.springframework.jdbc.support.lob.AbstractLobHandler
getBlobAsBinaryStream, getBlobAsBytes, getClobAsAsciiStream, getClobAsCharacterStream, getClobAsString
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

logger

protected final org.apache.commons.logging.Log logger
Constructor Detail

DefaultLobHandler

public DefaultLobHandler()
Method Detail

setWrapAsLob

public void setWrapAsLob(boolean wrapAsLob)
Specify whether to submit a byte array / String to the JDBC driver wrapped in a JDBC Blob / Clob object, using the JDBC setBlob / setClob method with a Blob / Clob argument.

Default is "false", using the common JDBC 2.0 setBinaryStream / setCharacterStream method for setting the content. Switch this to "true" for explicit Blob / Clob wrapping against JDBC drivers that are known to require such wrapping (e.g. PostgreSQL's).

This setting affects byte array / String arguments as well as stream arguments, unless "streamAsLob" overrides this handling to use JDBC 4.0's new explicit streaming support (if available).

See Also:
PreparedStatement.setBlob(int, java.sql.Blob), PreparedStatement.setClob(int, java.sql.Clob)

setStreamAsLob

public void setStreamAsLob(boolean streamAsLob)
Specify whether to submit a binary stream / character stream to the JDBC driver as explicit LOB content, using the JDBC 4.0 setBlob / setClob method with a stream argument.

Default is "false", using the common JDBC 2.0 setBinaryStream / setCharacterStream method for setting the content. Switch this to "true" for explicit JDBC 4.0 usage, provided that your JDBC driver actually supports those JDBC 4.0 operations (e.g. Derby's).

This setting affects stream arguments as well as byte array / String arguments, requiring JDBC 4.0 support. For supporting LOB content against JDBC 3.0, check out the "wrapAsLob" setting.

See Also:
PreparedStatement.setBlob(int, java.io.InputStream, long), PreparedStatement.setClob(int, java.io.Reader, long)

getBlobAsBytes

public byte[] getBlobAsBytes(java.sql.ResultSet rs,
                             int columnIndex)
                      throws java.sql.SQLException
Description copied from interface: LobHandler
Retrieve the given column as bytes from the given ResultSet. Might simply invoke ResultSet.getBytes or work with ResultSet.getBlob, depending on the database and driver.

Parameters:
rs - the ResultSet to retrieve the content from
columnIndex - the column index to use
Returns:
the content as byte array, or null in case of SQL NULL
Throws:
java.sql.SQLException - if thrown by JDBC methods
See Also:
ResultSet.getBytes(int)

getBlobAsBinaryStream

public java.io.InputStream getBlobAsBinaryStream(java.sql.ResultSet rs,
                                                 int columnIndex)
                                          throws java.sql.SQLException
Description copied from interface: LobHandler
Retrieve the given column as binary stream from the given ResultSet. Might simply invoke ResultSet.getBinaryStream or work with ResultSet.getBlob, depending on the database and driver.

Parameters:
rs - the ResultSet to retrieve the content from
columnIndex - the column index to use
Returns:
the content as binary stream, or null in case of SQL NULL
Throws:
java.sql.SQLException - if thrown by JDBC methods
See Also:
ResultSet.getBinaryStream(int)

getClobAsString

public java.lang.String getClobAsString(java.sql.ResultSet rs,
                                        int columnIndex)
                                 throws java.sql.SQLException
Description copied from interface: LobHandler
Retrieve the given column as String from the given ResultSet. Might simply invoke ResultSet.getString or work with ResultSet.getClob, depending on the database and driver.

Parameters:
rs - the ResultSet to retrieve the content from
columnIndex - the column index to use
Returns:
the content as String, or null in case of SQL NULL
Throws:
java.sql.SQLException - if thrown by JDBC methods
See Also:
ResultSet.getString(int)

getClobAsAsciiStream

public java.io.InputStream getClobAsAsciiStream(java.sql.ResultSet rs,
                                                int columnIndex)
                                         throws java.sql.SQLException
Description copied from interface: LobHandler
Retrieve the given column as ASCII stream from the given ResultSet. Might simply invoke ResultSet.getAsciiStream or work with ResultSet.getClob, depending on the database and driver.

Parameters:
rs - the ResultSet to retrieve the content from
columnIndex - the column index to use
Returns:
the content as ASCII stream, or null in case of SQL NULL
Throws:
java.sql.SQLException - if thrown by JDBC methods
See Also:
ResultSet.getAsciiStream(int)

getClobAsCharacterStream

public java.io.Reader getClobAsCharacterStream(java.sql.ResultSet rs,
                                               int columnIndex)
                                        throws java.sql.SQLException
Description copied from interface: LobHandler
Retrieve the given column as character stream from the given ResultSet. Might simply invoke ResultSet.getCharacterStream or work with ResultSet.getClob, depending on the database and driver.

Parameters:
rs - the ResultSet to retrieve the content from
columnIndex - the column index to use
Returns:
the content as character stream
Throws:
java.sql.SQLException - if thrown by JDBC methods
See Also:
ResultSet.getCharacterStream(int)

getLobCreator

public LobCreator getLobCreator()
Description copied from interface: LobHandler
Create a new LobCreator instance, i.e. a session for creating BLOBs and CLOBs. Needs to be closed after the created LOBs are not needed anymore - typically after statement execution or transaction completion.

Returns:
the new LobCreator instance
See Also:
LobCreator.close()

Spring Framework