com.jcabi.log

Class Logger

java.lang.Object

com.jcabi.log.Logger

public final class Logger
extends Object

Universal logger, and adapter between your app and SLF4J API.

Instead of relying on some logging engine you can use this class, which transforms all messages to SLF4J. This approach gives you a perfect decoupling of business logic and logging mechanism. All methods in the class are called statically, without the necessity to instantiate the class.

Use it like this in any class, and in any package:

 package com.example.XXX;
 import com.jcabi.log.Logger;
 public class MyClass {
   public void foo(Integer num) {
     Logger.info(this, "foo(%d) just called", num);
   }
 }
 

Or statically (pay attention to MyClass.class):

 public class MyClass {
   public static void foo(Integer num) {
     Logger.info(MyClass.class, "foo(%d) just called", num);
   }
 }
 

Exact binding between SLF4J and logging facility has to be specified in pom.xml of your project (or in classpath directly).

For performance reasons in most cases before sending a TRACE or DEBUG log message you may check whether this logging level is enabled in the project, e.g.:

 //...
 if (Logger.isTraceEnabled(this)) {
   Logger.trace(this, "#foo() called");
 }
 //...
 

There is only one reason to do so - if you want to save time spent on preparing of the arguments. By default, such a call is made inside every method of Logger class.

Since:

0.1

Version:

$Id$

Author:

Yegor Bugayenko (yegor@jcabi.com)

Method Summary

Methods

Modifier and Type	Method and Description
static void	debug(Object source, String msg, Object... args) Protocol one message, with DEBUG priority level.
static void	error(Object source, String msg, Object... args) Protocol one message, with ERROR priority level.
static String	format(String fmt, Object... args) Format one string.
static void	info(Object source, String msg, Object... args) Protocol one message, with INFO priority level.
static boolean	isDebugEnabled(Object source) Validates whether DEBUG priority level is enabled for this particular logger.
static boolean	isInfoEnabled(Object source) Validates whether INFO priority level is enabled for this particular logger.
static boolean	isTraceEnabled(Object source) Validates whether TRACE priority level is enabled for this particular logger.
static boolean	isWarnEnabled(Object source) Validates whether INFO priority level is enabled for this particular logger.
static void	trace(Object source, String msg, Object... args) Protocol one message, with TRACE priority level.
static void	warn(Object source, String msg, Object... args) Protocol one message, with WARN priority level.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

format

public static String format(String fmt,
            Object... args)

Format one string.

Parameters:

fmt - The format

args - List of arbitrary arguments

Returns:

Formatted string

trace

public static void trace(Object source,
         String msg,
         Object... args)

Protocol one message, with TRACE priority level.

Parameters:

source - The source of the logging operation

msg - The text message to be logged, with meta-tags

args - List of arguments

debug

public static void debug(Object source,
         String msg,
         Object... args)

Protocol one message, with DEBUG priority level.

Parameters:

source - The source of the logging operation

msg - The text message to be logged, with meta-tags

args - List of arguments

info

public static void info(Object source,
        String msg,
        Object... args)

Protocol one message, with INFO priority level.

Parameters:

source - The source of the logging operation

msg - The text message to be logged, with meta-tags

args - List of arguments

warn

public static void warn(Object source,
        String msg,
        Object... args)

Protocol one message, with WARN priority level.

Parameters:

source - The source of the logging operation

msg - The text message to be logged, with meta-tags

args - List of arguments

error

public static void error(Object source,
         String msg,
         Object... args)

Protocol one message, with ERROR priority level.

Parameters:

source - The source of the logging operation

msg - The text message to be logged, with meta-tags

args - List of arguments

isTraceEnabled

public static boolean isTraceEnabled(Object source)

Validates whether TRACE priority level is enabled for this particular logger.

Parameters:

source - The source of the logging operation

Returns:

Is it enabled?

isDebugEnabled

public static boolean isDebugEnabled(Object source)

Validates whether DEBUG priority level is enabled for this particular logger.

Parameters:

source - The source of the logging operation

Returns:

Is it enabled?

isInfoEnabled

public static boolean isInfoEnabled(Object source)

Validates whether INFO priority level is enabled for this particular logger.

Parameters:

source - The source of the logging operation

Returns:

Is it enabled?

Since:

1.0.5

isWarnEnabled

public static boolean isWarnEnabled(Object source)

Validates whether INFO priority level is enabled for this particular logger.

Parameters:

source - The source of the logging operation

Returns:

Is it enabled?

Since:

1.0.5