org.apache.logging.log4j.core.appender.db
Class AbstractDatabaseManager

java.lang.Object
  extended by org.apache.logging.log4j.core.appender.AbstractManager
      extended by org.apache.logging.log4j.core.appender.db.AbstractDatabaseManager
Direct Known Subclasses:
JdbcDatabaseManager, JpaDatabaseManager

public abstract class AbstractDatabaseManager
extends AbstractManager

Manager that allows database appenders to have their configuration reloaded without losing events.


Nested Class Summary
protected static class AbstractDatabaseManager.AbstractFactoryData
          Implementations should extend this class for passing data between the getManager method and the manager factory class.
 
Field Summary
 
Fields inherited from class org.apache.logging.log4j.core.appender.AbstractManager
count, LOGGER
 
Constructor Summary
protected AbstractDatabaseManager(String name, int bufferSize)
          Instantiates the base manager.
 
Method Summary
protected abstract  void commitAndClose()
          Commits any active transaction (if applicable) and disconnects from the database (returns the connection to the connection pool).
protected abstract  void connectAndStart()
          Connects to the database and starts a transaction (if applicable).
 void flush()
          This method is called automatically when the buffer size reaches its maximum or at the beginning of a call to shutdown().
protected static
<M extends AbstractDatabaseManager,T extends AbstractDatabaseManager.AbstractFactoryData>
M
getManager(String name, T data, ManagerFactory<M,T> factory)
          Implementations should define their own getManager method and call this method from that to create or get existing managers.
 boolean isRunning()
          Indicates whether the manager is currently connected startup() has been called and shutdown() has not been called).
 void releaseSub()
          May be overridden by Managers to perform processing while the Manager is being released and the lock is held.
 void shutdown()
          This method is called from the AbstractManager.release() method when the appender is stopped or the appender's manager is replaced.
protected abstract  void shutdownInternal()
          Implementations should implement this method to perform any proprietary disconnection / shutdown operations.
 void startup()
          This method is called within the appender when the appender is started.
protected abstract  void startupInternal()
          Implementations should implement this method to perform any proprietary startup operations.
 String toString()
           
 void write(LogEvent event)
          This method manages buffering and writing of events.
protected abstract  void writeInternal(LogEvent event)
          Performs the actual writing of the event in an implementation-specific way.
 
Methods inherited from class org.apache.logging.log4j.core.appender.AbstractManager
getContentFormat, getCount, getName, hasManager, release
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

AbstractDatabaseManager

protected AbstractDatabaseManager(String name,
                                  int bufferSize)
Instantiates the base manager.

Parameters:
name - The manager name, which should include any configuration details that one might want to be able to reconfigure at runtime, such as database name, username, (hashed) password, etc.
bufferSize - The size of the log event buffer.
Method Detail

startupInternal

protected abstract void startupInternal()
                                 throws Exception
Implementations should implement this method to perform any proprietary startup operations. This method will never be called twice on the same instance. It is safe to throw any exceptions from this method. This method does not necessarily connect to the database, as it is generally unreliable to connect once and use the same connection for hours.

Throws:
Exception

startup

public final void startup()
This method is called within the appender when the appender is started. If it has not already been called, it calls startupInternal() and catches any exceptions it might throw.


shutdownInternal

protected abstract void shutdownInternal()
                                  throws Exception
Implementations should implement this method to perform any proprietary disconnection / shutdown operations. This method will never be called twice on the same instance, and it will only be called after startupInternal(). It is safe to throw any exceptions from this method. This method does not necessarily disconnect from the database for the same reasons outlined in startupInternal().

Throws:
Exception

shutdown

public final void shutdown()
This method is called from the AbstractManager.release() method when the appender is stopped or the appender's manager is replaced. If it has not already been called, it calls shutdownInternal() and catches any exceptions it might throw.


isRunning

public final boolean isRunning()
Indicates whether the manager is currently connected startup() has been called and shutdown() has not been called).

Returns:
true if the manager is connected.

connectAndStart

protected abstract void connectAndStart()
Connects to the database and starts a transaction (if applicable). With buffering enabled, this is called when flushing the buffer begins, before the first call to writeInternal(org.apache.logging.log4j.core.LogEvent). With buffering disabled, this is called immediately before every invocation of writeInternal(org.apache.logging.log4j.core.LogEvent).


writeInternal

protected abstract void writeInternal(LogEvent event)
Performs the actual writing of the event in an implementation-specific way. This method is called immediately from write(LogEvent) if buffering is off, or from flush() if the buffer has reached its limit.

Parameters:
event - The event to write to the database.

commitAndClose

protected abstract void commitAndClose()
Commits any active transaction (if applicable) and disconnects from the database (returns the connection to the connection pool). With buffering enabled, this is called when flushing the buffer completes, after the last call to writeInternal(org.apache.logging.log4j.core.LogEvent). With buffering disabled, this is called immediately after every invocation of writeInternal(org.apache.logging.log4j.core.LogEvent).


flush

public final void flush()
This method is called automatically when the buffer size reaches its maximum or at the beginning of a call to shutdown(). It can also be called manually to flush events to the database.


write

public final void write(LogEvent event)
This method manages buffering and writing of events.

Parameters:
event - The event to write to the database.

releaseSub

public final void releaseSub()
Description copied from class: AbstractManager
May be overridden by Managers to perform processing while the Manager is being released and the lock is held.

Overrides:
releaseSub in class AbstractManager

toString

public final String toString()
Overrides:
toString in class Object

getManager

protected static <M extends AbstractDatabaseManager,T extends AbstractDatabaseManager.AbstractFactoryData> M getManager(String name,
                                                                                                                        T data,
                                                                                                                        ManagerFactory<M,T> factory)
Implementations should define their own getManager method and call this method from that to create or get existing managers.

Type Parameters:
M - The concrete manager type.
T - The concrete AbstractDatabaseManager.AbstractFactoryData type.
Parameters:
name - The manager name, which should include any configuration details that one might want to be able to reconfigure at runtime, such as database name, username, (hashed) password, etc.
data - The concrete instance of AbstractDatabaseManager.AbstractFactoryData appropriate for the given manager.
factory - A factory instance for creating the appropriate manager.
Returns:
a new or existing manager of the specified type and name.


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