Open eCard

h1. Logging guidelines

{{toc}}

h2. Framework

h3. SLF4J (Simple Logging Facade for Java)

"Documentation":http://www.slf4j.org/docs.html

h3. Maven

No dependency SHOULD be added to the module POM. The dependencies are already defined in the ecard client POM.

h3. Preamble

<pre>

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

private static final Logger logger = LoggerFactory.getLogger(MYCLASS.class);

</pre>

h3. SLF4J with java.util.logging backend

This code SHOULD only be using in JUnit tests.

<pre>

// Reset configuration to avoid multiple log entries.

java.util.logging.LogManager.getLogManager().reset();

// Add new console handler

ConsoleHandler ch = new ConsoleHandler();

ch.setLevel(Level.ALL);

// Set logging level

LogManager.getLogger(MYCLASS.class.getName()).setLevel(Level.FINE);

// Log message as jdk logging level INFO

logger.info(LoggingConstants.FINE, "Log my message: {}", message);

// Log message as jdk logging level FINE

logger.debug(LoggingConstants.FINE, "Log my message: {}", message);

// Log message as jdk logging level WARNING

logger.warn(LoggingConstants.FINE, "Log my message: {}", message);

// Log message as jdk logging level SEVERE

logger.error(LoggingConstants.FINE, "Log my message: {}", message);

</pre>

h2. Levels

h3. Overview

Marker are specified in @org.openecard.client.common.logging.LoggingConstants@

* THROWING: [[Logging guidelines#Exceptions|Exceptions]]

* SEVERE:

* INFO:

* CONFIG:

* FINE: [[Logging guidelines#Exceptions|Messages]]

* FINER: [[Logging guidelines#Exceptions|Events]]

* FINEST:

h3. Exceptions

<pre>

import org.openecard.client.common.logging.LoggingConstants;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

private static final Logger logger = LoggerFactory.getLogger(MYCLASS.class);

try{

 ...

} catch (Exception e){

  // <editor-fold defaultstate="collapsed" desc="log exception">

  logger.error(LoggingConstants.THROWING, "Exception", e);

  // </editor-fold>

}

</pre>

h3. Messages

Messages including  APDUs, eCard-API messages, PAOS messages.

<pre>

import org.openecard.client.common.logging.LoggingConstants;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

private static final Logger logger = LoggerFactory.getLogger(MYCLASS.class);

// <editor-fold defaultstate="collapsed" desc="log message">

logger.debug(LoggingConstants.FINE, "Message received:\n{}", message);

// </editor-fold>

// <editor-fold defaultstate="collapsed" desc="log message">

logger.debug(LoggingConstants.FINE, "Message sent:\n{}", message);

// </editor-fold>

</pre>

h3. Events

E.g. GUI events.

<pre>

import org.openecard.client.common.logging.LoggingConstants;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

private static final Logger logger = LoggerFactory.getLogger(MYCLASS.class);

// <editor-fold defaultstate="collapsed" desc="log event">

logger.debug(LoggingConstants.FINER, "Event: {}", event);

// </editor-fold>

</pre>

h2. Notes

h3. Trace statements are omitted

<pre>

logger.trace("Trace a message: {}", message);

</pre>

Will be replaced by "slf4j extension":http://www.slf4j.org/extensions.html#javaagent.

h2. Examples

h3. APDU logging

<pre>

import org.openecard.client.common.ECardConstants;

import org.openecard.client.common.logging.LogManager;

java.util.logging.LogManager.getLogManager().reset();

ConsoleHandler ch = new ConsoleHandler();

ch.setLevel(Level.ALL);

LogManager.getLogger("org.openecard.client.ifd.scio.wrapper").addHandler(ch);

LogManager.getLogger("org.openecard.client.ifd.scio.wrapper").setLevel(Level.FINE);

</pre>