public class BR.unicamp.Guarana.MetaLogger

java.lang.Object
   |
   +----BR.unicamp.Guarana.MetaObject
           |
           +----BR.unicamp.Guarana.MetaLogger

public class MetaLogger
  extends MetaObject

Logs all Operations, Results, Messages and Reconfiguration requests. It can be used for starting-up an originally non-reflective application with logging enabled.

See also:

main

MetaLogger(Writer)

Creates a MetaLogger that logs to the specified Writer

MetaLogger(PrintWriter)

Creates a MetaLogger that logs to the specified PrintWriter.

MetaLogger(OutputStream)

Creates a MetaLogger that logs to the specified OutputStream. It will be wrapped in a

MetaLogger()

Create a MetaLogger that logs to System.out.

configure(Object, Object)

Copies itself into the meta-configuration of the new object, as long as this object is not

handle(Result, Object)

Logs a `Result' string.

handle(Message, Object)

Logs a `Message' string.

handle(Operation, Object)

Logs an `Operation' string.

initialize(OperationFactory, Object)

Logs an initialization message.

main(String[])

The MetaLogger class can be used as an application starter. Running `guarana

reconfigure(Object, MetaObject, MetaObject)

Accepts any reconfiguration request targeted to itself

release(Object)

Logs an object release message.

setPrefix(String)

Sets a prefix String, prepended to every line printed by this MetaLogger.

public MetaLogger();

Create a MetaLogger that logs to System.out.

MetaLogger

public MetaLogger(OutputStream out);

Creates a MetaLogger that logs to the specified OutputStream. It will be wrapped in a PrintWriter with autoflush enabled.

Parameters:

out - the OutputStream that will get all logging.

MetaLogger

public MetaLogger(Writer out);

Creates a MetaLogger that logs to the specified Writer. It will be wrapper in a PrintWriter with autoflush enabled.

Parameters:

out - the Writer that will get all logging.

MetaLogger

public MetaLogger(PrintWriter out);

Creates a MetaLogger that logs to the specified PrintWriter.

Parameters:

out - the PrintWriter that will get all logging.

public MetaLogger setPrefix(String prefix);

Sets a prefix String, prepended to every line printed by this MetaLogger.

Parameters:

prefix - the prefix String. It should not be null, otherwise the prefix will be the string `null'.

Returns:

the MetaLogger itself, so this can be chained with construction or whatever.

handle

public Result handle(Operation op,
                     Object ob);

Logs an `Operation' string.

Parameters:

op - the Operation to be logged.

ob - the target Object of the Operation. Unused.

Returns:

a request to inspect the result of the Operation: Result.inspectResult.

Overrides:

handle in class MetaObject

handle

public Result handle(Result res,
                     Object ob);

Logs a `Result' string.

Parameters:

res - the Result of an Operation.

ob - the target Object of the Operation.

Returns:

null, i.e., the provided Result should be maintained.

Overrides:

handle in class MetaObject

handle

public void handle(Message msg,
                   Object ob);

Logs a `Message' string.

Parameters:

msg - the Message to be logged.

ob - the Object whose meta-configuration was the target of the Message broadcast.

Overrides:

handle in class MetaObject

configure

public MetaObject configure(Object newObject,
                            Object object);

Copies itself into the meta-configuration of the new object, as long as this object is not a String or a StringBuffer. Logs a message informing about the configuration request, and another indicating whether it propagated itself or not.

Parameters:

newObject - the new Object whose meta-configuration is to be provided. Just used for printing the Object identification.

object - the Object whose meta-configuration the new meta-configuration was based on. Just used for printing its identification.

Returns:

this or null, depending on whether it decided to propagate itself or not.

Overrides:

configure in class MetaObject

reconfigure

public MetaObject reconfigure(Object object,
                              MetaObject prev,
                              MetaObject next);

Accepts any reconfiguration request targeted to itself. All requests are logged. Furthermore, if the reconfiguration request is targeted on itself, an acceptance message is logged; otherwise, a message stating that the request was ignored is.

Parameters:

object - the Object whose meta-configuration is to be affected. Used only for logging.

prev - the MetaObject to be replaced.

next - the MetaObject that should take its place.

Returns:

next if prev == this, this otherwise.

Overrides:

reconfigure in class MetaObject

initialize

public void initialize(OperationFactory fact,
                       Object obj);

Logs an initialization message.

Parameters:

fact - ignored.

obj - the Object whose meta-configuration is to be initialized. Used just for logging purposes.

Overrides:

initialize in class MetaObject

release

public void release(Object obj);

Logs an object release message.

Parameters:

obj - the Object to be released. Used just for logging purposes.

Overrides:

release in class MetaObject

main

public static void main(String[] argv)
  throws java.lang.ClassNotFoundException, java.lang.NoSuchMethodException, java.lang.IllegalAccessException, java.lang.reflect.InvocationTargetException;

The MetaLogger class can be used as an application starter. Running `guarana BR.unicamp.Guarana.MetaLogger classname arguments ...' is equivalent to associating classname with a MetaLogger that logs to System.out and invoking classname.main with the provided argument list.

If the first argument is a number instead of a classname, it should be followed by a list of classnames that will be associated with MetaLoggers that log to System.out. After this list, a classname and an argument list should appear. In this case, the classname will not be associated with a MetaLogger. For example: `guarana BR.unicamp.Guarana.MetaLogger 3 A B C D args' will cause MetaLoggers to be associated with classes A, B and C. Finally, D.main will be invoked with the provided argument list.

BR.unicamp.Guarana.MetaLogger.html