Package org.jboss.elemento.logger

package org.jboss.elemento.logger

Provides a lightweight logging wrapper around console.log that uses categories, log levels, and a predefined log format.

Getting Loggers

Retrieve a logger using Logger.getLogger(String) with an arbitrary category string. Using hierarchical categories (such as fully qualified class names) enables level overrides for subcategories:

package org.acme;

public class Foo {
    private static final Logger logger = Logger.getLogger(Foo.class.getName());

    public void bar() {
        logger.info("Processing request");
        logger.debug("Request details: %s", request);
    }
}

Log Methods

The logger provides four log levels, each delegating to the corresponding console method:

1. Logger.error(String, Object...) → console.error()
2. Logger.warn(String, Object...) → console.warn()
3. Logger.info(String, Object...) → console.info()
4. Logger.debug(String, Object...) → console.debug()

All log methods support string substitutions and accept a variable list of parameters for formatting.

Log Levels

The global log level is set using Logger.setLevel(Level). Override the level for a specific category with Logger.setLevel(String, Level), or reset a category to the global level using Logger.resetLevel(String).

If a category contains ., it is interpreted hierarchically. For example, overriding org.jboss applies to all subcategories like org.jboss.elemento (unless explicitly overridden otherwise).

Log Format

The log format is predefined as:

 HH:mm:ss.SSS <level> [<category>] <message>
 

and cannot be customized. Categories are trimmed and right-aligned. If the category is a fully qualified class name, package names are shortened (e.g., org.jboss.elemento.Logger becomes o.j.e.Logger).

JavaScript API

The logger exports methods to JavaScript (e.g., for use in browser dev tools) to control log levels:

• org.jboss.elemento.logger.Logger.setLevel(String level) - sets the global log level
• org.jboss.elemento.logger.Logger.setLevel(String category, String level) - overrides the log level for one category
• org.jboss.elemento.logger.Logger.resetLevel(String category) - resets the log level for the category to the global log level

Please use the fully qualified name when calling these methods from JavaScript!

Additional Features

The logger provides methods for:

• Grouping - Logger.groupDebug(String, Object...), Logger.groupInfo(String, Object...), Logger.groupWarn(String, Object...), Logger.groupError(String, Object...), Logger.groupEnd()
• Timers - Logger.timeDebug(String), Logger.timeInfo(String), Logger.timeWarn(String), Logger.timeError(String), Logger.timeEnd(String)
• Initialization from URL - Logger.initFrom(elemental2.dom.Location) to set the global log level from a query parameter

See Also:

• Logger
• Level

Related Packages

Package	Description
org.jboss.elemento	Elemento simplifies working with GWT Elemental2 by providing a fluent API for building HTML element hierarchies, typesafe CSS selectors, and helper methods for common DOM operations.
org.jboss.elemento.flow	Provides an API for executing asynchronous tasks in parallel, sequentially, or repeatedly based on conditions.
org.jboss.elemento.intl	Provides type-safe Java mappings for the JavaScript Intl API, enabling locale-aware formatting of dates, times, numbers, lists, durations, and relative times.
org.jboss.elemento.mathml	Provides support for creating and manipulating MathML (Mathematical Markup Language) elements using a fluent builder API.
org.jboss.elemento.router	Provides a minimally invasive client-side routing solution for single-page applications.
org.jboss.elemento.svg	Provides classes and interfaces for creating and manipulating SVG (Scalable Vector Graphics) elements using a fluent builder API.

Class	Description
Level	Log levels supported by Logger
Logger	Small wrapper around console.log that uses categories, log levels, and a predefined log format.