The ODBCAppender provides for sending log events to a database.
Each append call adds to an ArrayList
buffer. When the buffer is filled each log event is placed in a sql statement (configurable) and executed.
BufferSize, db URL, User, & Password are configurable options in the standard log4j ways.
The setSql(String sql)
sets the SQL statement to be used for logging -- this statement is sent to a PatternLayout
(either created automaticly by the appender or added by the user). Therefore by default all the conversion patterns in PatternLayout
can be used inside of the statement. (see the test cases for examples)
Overriding the getLogStatement method allows more explicit control of the statement used for logging.
For use as a base class:
closeConnection
to handle the connection you generated. Typically this would return the connection to the pool it came from.
Public Member Functions | |
ODBCAppender () | |
virtual | ~ODBCAppender () |
virtual void | setOption (const LogString &option, const LogString &value) |
Set options. | |
virtual void | activateOptions (log4cxx::helpers::Pool &p) |
Activate the specified options. | |
void | append (const spi::LoggingEventPtr &event, log4cxx::helpers::Pool &) |
Adds the event to the buffer. | |
virtual void | close () |
Closes the appender, flushing the buffer first then closing the default connection if it is open. | |
virtual void | flushBuffer (log4cxx::helpers::Pool &p) |
loops through the buffer of LoggingEvents, gets a sql string from getLogStatement() and sends it to execute(). | |
virtual bool | requiresLayout () const |
ODBCAppender requires a layout. | |
void | setSql (const LogString &s) |
Set pre-formated statement eg: insert into LogTable (msg) values ("%m"). | |
const LogString & | getSql () const |
Returns pre-formated statement eg: insert into LogTable (msg) values ("%m"). | |
void | setUser (const LogString &user) |
void | setURL (const LogString &url) |
void | setPassword (const LogString &password) |
void | setBufferSize (size_t newBufferSize) |
const LogString & | getUser () const |
const LogString & | getURL () const |
const LogString & | getPassword () const |
size_t | getBufferSize () const |
Protected Types | |
typedef void * | SQLHDBC |
typedef void * | SQLHENV |
typedef void * | SQLHANDLE |
typedef short | SQLSMALLINT |
Protected Member Functions | |
LogString | getLogStatement (const spi::LoggingEventPtr &event, helpers::Pool &p) const |
By default getLogStatement sends the event to the required Layout object. | |
virtual void | execute (const LogString &sql, log4cxx::helpers::Pool &p) |
Override this to provide an alertnate method of getting connections (such as caching). | |
virtual void | closeConnection (SQLHDBC con) |
Override this to return the connection to a pool, or to clean up the resource. | |
virtual SQLHDBC | getConnection (log4cxx::helpers::Pool &p) |
Override this to link with your connection pooling system. | |
Protected Attributes | |
LogString | databaseURL |
URL of the DB for default connection handling. | |
LogString | databaseUser |
User to connect as for default connection handling. | |
LogString | databasePassword |
User to use for default connection handling. | |
SQLHDBC | connection |
Connection used by default. | |
SQLHENV | env |
LogString | sqlStatement |
Stores the string given to the pattern layout for conversion into a SQL statement, eg: insert into LogTable (Thread, File, Message) values ("%t", "%F", "%m"). | |
size_t | bufferSize |
size of LoggingEvent buffer before writing to the database. | |
std::list< spi::LoggingEventPtr > | buffer |
ArrayList holding the buffer of Logging Events. |
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Activate the specified options.
Reimplemented from AppenderSkeleton. |
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Adds the event to the buffer. When full the buffer is flushed. Implements AppenderSkeleton. |
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Closes the appender, flushing the buffer first then closing the default connection if it is open.
Implements Appender. |
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Override this to return the connection to a pool, or to clean up the resource. The default behavior holds a single connection open until the appender is closed (typically when garbage collected). |
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Override this to provide an alertnate method of getting connections (such as caching). One method to fix this is to open connections at the start of flushBuffer() and close them at the end. I use a connection pool outside of ODBCAppender which is accessed in an override of this method. |
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loops through the buffer of LoggingEvents, gets a sql string from getLogStatement() and sends it to execute(). Errors are sent to the errorHandler. If a statement fails the LoggingEvent stays in the buffer! |
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Override this to link with your connection pooling system. By default this creates a single connection which is held open until the object is garbage collected. |
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By default getLogStatement sends the event to the required Layout object. The layout will format the given pattern into a workable SQL string. Overriding this provides direct access to the LoggingEvent when constructing the logging statement. |
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Returns pre-formated statement eg: insert into LogTable (msg) values ("%m").
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ODBCAppender requires a layout.
Implements Appender. |
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Set options.
Reimplemented from AppenderSkeleton. |
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Set pre-formated statement eg: insert into LogTable (msg) values ("%m").
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ArrayList holding the buffer of Logging Events.
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size of LoggingEvent buffer before writing to the database. Default is 1. |
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Connection used by default.
The connection is opened the first time it is needed and then held open until the appender is closed (usually at garbage collection). This behavior is best modified by creating a sub-class and overriding the |
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User to use for default connection handling.
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URL of the DB for default connection handling.
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User to connect as for default connection handling.
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Stores the string given to the pattern layout for conversion into a SQL statement, eg: insert into LogTable (Thread, File, Message) values ("%t", "%F", "%m"). Be careful of quotes in your messages! Also see PatternLayout. |