public class DefaultLobHandler extends AbstractLobHandler
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's drivers at all; as of Oracle 10g,
it does work but may still come with LOB size limitations. Consider using
recent Oracle drivers even when working against an older database server.
See the LobHandler
javadoc for the full set of recommendations.
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.
Finally, primarily as a direct equivalent to OracleLobHandler
,
this LobHandler also supports the creation of temporary BLOB/CLOB objects.
Consider switching the "createTemporaryLob"
property to "true" when "streamAsLob" happens to run into LOB size limitations.
See the LobHandler
interface javadoc for a summary of recommendations.
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)
Modifier and Type | Class and Description |
---|---|
protected class |
DefaultLobHandler.DefaultLobCreator
Default LobCreator implementation as an inner class.
|
Modifier and Type | Field and Description |
---|---|
private boolean |
createTemporaryLob |
protected Log |
logger |
private boolean |
streamAsLob |
private boolean |
wrapAsLob |
Constructor and Description |
---|
DefaultLobHandler() |
Modifier and Type | Method and Description |
---|---|
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 |
setCreateTemporaryLob(boolean createTemporaryLob)
Specify whether to copy a byte array / String into a temporary JDBC
Blob / Clob object created through the JDBC 4.0
createBlob /
createClob methods. |
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. |
getBlobAsBinaryStream, getBlobAsBytes, getClobAsAsciiStream, getClobAsCharacterStream, getClobAsString
protected final Log logger
private boolean wrapAsLob
private boolean streamAsLob
private boolean createTemporaryLob
public void setWrapAsLob(boolean wrapAsLob)
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 for access to OID
columns, whereas BYTEA columns need to be accessed the standard way).
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).
PreparedStatement.setBlob(int, java.sql.Blob)
,
PreparedStatement.setClob(int, java.sql.Clob)
public void setStreamAsLob(boolean streamAsLob)
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 streaming, 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.
PreparedStatement.setBlob(int, java.io.InputStream, long)
,
PreparedStatement.setClob(int, java.io.Reader, long)
public void setCreateTemporaryLob(boolean createTemporaryLob)
createBlob
/
createClob
methods.
Default is "false", using the common JDBC 2.0 setBinaryStream
/ setCharacterStream
method for setting the content. Switch this
to "true" for explicit Blob / Clob creation using JDBC 4.0.
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.
Connection.createBlob()
,
Connection.createClob()
public byte[] getBlobAsBytes(java.sql.ResultSet rs, int columnIndex) throws java.sql.SQLException
LobHandler
ResultSet.getBytes
or work with
ResultSet.getBlob
, depending on the database and driver.rs
- the ResultSet to retrieve the content fromcolumnIndex
- the column index to usenull
in case of SQL NULLjava.sql.SQLException
- if thrown by JDBC methodsResultSet.getBytes(int)
public java.io.InputStream getBlobAsBinaryStream(java.sql.ResultSet rs, int columnIndex) throws java.sql.SQLException
LobHandler
ResultSet.getBinaryStream
or work with
ResultSet.getBlob
, depending on the database and driver.rs
- the ResultSet to retrieve the content fromcolumnIndex
- the column index to usenull
in case of SQL NULLjava.sql.SQLException
- if thrown by JDBC methodsResultSet.getBinaryStream(int)
public java.lang.String getClobAsString(java.sql.ResultSet rs, int columnIndex) throws java.sql.SQLException
LobHandler
ResultSet.getString
or work with
ResultSet.getClob
, depending on the database and driver.rs
- the ResultSet to retrieve the content fromcolumnIndex
- the column index to usenull
in case of SQL NULLjava.sql.SQLException
- if thrown by JDBC methodsResultSet.getString(int)
public java.io.InputStream getClobAsAsciiStream(java.sql.ResultSet rs, int columnIndex) throws java.sql.SQLException
LobHandler
ResultSet.getAsciiStream
or work with
ResultSet.getClob
, depending on the database and driver.rs
- the ResultSet to retrieve the content fromcolumnIndex
- the column index to usenull
in case of SQL NULLjava.sql.SQLException
- if thrown by JDBC methodsResultSet.getAsciiStream(int)
public java.io.Reader getClobAsCharacterStream(java.sql.ResultSet rs, int columnIndex) throws java.sql.SQLException
LobHandler
ResultSet.getCharacterStream
or work with
ResultSet.getClob
, depending on the database and driver.rs
- the ResultSet to retrieve the content fromcolumnIndex
- the column index to usejava.sql.SQLException
- if thrown by JDBC methodsResultSet.getCharacterStream(int)
public LobCreator getLobCreator()
LobHandler
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.LobCreator.close()