Apache log4cxx  Version 0.10.0
ODBCAppender Class Reference
Inheritance diagram for ODBCAppender:
AppenderSkeleton Appender ObjectImpl OptionHandler Object Object

List of all members.

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 LogStringgetSql () 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 LogStringgetUser () const
const LogStringgetURL () const
const LogStringgetPassword () 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::LoggingEventPtrbuffer
 ArrayList holding the buffer of Logging Events.

Detailed Description

WARNING: This version of ODBCAppender is very likely to be completely replaced in the future. Moreoever, it does not log exceptions.

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:

  • Override getConnection() to pass any connection you want. Typically this is used to enable application wide connection pooling.

  • Override closeConnection -- if you override getConnection make sure to implement closeConnection to handle the connection you generated. Typically this would return the connection to the pool it came from.

  • Override getLogStatement to produce specialized or dynamic statements. The default uses the sql option value.


Member Typedef Documentation

typedef void* SQLHANDLE [protected]
typedef void* SQLHDBC [protected]
typedef void* SQLHENV [protected]
typedef short SQLSMALLINT [protected]

Constructor & Destructor Documentation

virtual ~ODBCAppender ( ) [virtual]

Member Function Documentation

virtual void activateOptions ( log4cxx::helpers::Pool p) [virtual]

Activate the specified options.

Reimplemented from AppenderSkeleton.

void append ( const spi::LoggingEventPtr event,
log4cxx::helpers::Pool  
) [virtual]

Adds the event to the buffer.

When full the buffer is flushed.

Implements AppenderSkeleton.

virtual void close ( ) [virtual]

Closes the appender, flushing the buffer first then closing the default connection if it is open.

Implements Appender.

virtual void closeConnection ( SQLHDBC  con) [protected, virtual]

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).

virtual void execute ( const LogString sql,
log4cxx::helpers::Pool p 
) [protected, virtual]

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.

virtual void flushBuffer ( log4cxx::helpers::Pool p) [virtual]

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!

size_t getBufferSize ( ) const [inline]
virtual SQLHDBC getConnection ( log4cxx::helpers::Pool p) [protected, virtual]

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.

LogString getLogStatement ( const spi::LoggingEventPtr event,
helpers::Pool p 
) const [protected]

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.

const LogString& getPassword ( ) const [inline]
const LogString& getSql ( ) const [inline]

Returns pre-formated statement eg: insert into LogTable (msg) values ("%m")

const LogString& getURL ( ) const [inline]
const LogString& getUser ( ) const [inline]
virtual bool requiresLayout ( ) const [inline, virtual]

ODBCAppender requires a layout.

Implements Appender.

void setBufferSize ( size_t  newBufferSize) [inline]
virtual void setOption ( const LogString option,
const LogString value 
) [virtual]

Set options.

Reimplemented from AppenderSkeleton.

void setPassword ( const LogString password) [inline]
void setSql ( const LogString s)

Set pre-formated statement eg: insert into LogTable (msg) values ("%m")

void setURL ( const LogString url) [inline]
void setUser ( const LogString user) [inline]

Member Data Documentation

std::list<spi::LoggingEventPtr> buffer [protected]

ArrayList holding the buffer of Logging Events.

size_t bufferSize [protected]

size of LoggingEvent buffer before writing to the database.

Default is 1.

SQLHDBC connection [protected]

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 getConnection and closeConnection methods.

User to use for default connection handling.

LogString databaseURL [protected]

URL of the DB for default connection handling.

LogString databaseUser [protected]

User to connect as for default connection handling.

SQLHENV env [protected]
LogString sqlStatement [protected]

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.


The documentation for this class was generated from the following file:
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