Welcome to SLF4j-format-jdk14

Decorator for SLF4J format extension to support java.util.logging style message format and localization with a resource bundle.

How to install

slf4j-format-jdk14 is published at Maven Central.

When your project uses Gradle, you can specify it like as follows.

dependencies {
    implementation 'tokyo.northside:slf4j-format-jdk14:<VERSION>'
}

Please check a Maven Central repository for details.

Dependency

slf4j-format-jdk14 depends on slf4j-api version 2.0.7. It is compatible with Java 11 and later.

How to use

slf4j-format-jdk14 provide a class of Decorator design pattern. It wraps org.slf4j.Logger object, and LoggingEventBuilder object which the org.slf4j.Logger instance returns when calling atLevel(Level) method. Decorated object support all the methods which supported by SLF4J Logger provide. It also provides additional methods logRB and setMessageRB which accept a key of ResourceBundle for localization.

Usage with tokyo.northside.logging.LoggerFactory

slf4j-format-jdk14 provide tokyo.northside.logging.LoggerFactory class that can be used as similar as genuine org.slf4j.LoggerFactory.

After create tokyo.northside.logging.ILogger instance, you can use it as same as slf4j Logger and enjoy extension setMessageRB method that accept ResourceBundle key.

import tokyo.northside.logging.ILogger;
import tokyo.northside.logging.LoggerFactory;

class Main {
    public static void example() {
        ResourceBundle bundle = ResourceBundle.getBundle("org/example/Bundle");
        ILogger logger = LoggerFactory.getLogger(Logger.ROOT_LOGGER_NAME, bundle);

        try {
            logger.atInfo().log("JUL style format {0}", "argument");
        } catch (Exception ex) {
            // get format string from bundle
            logger.atError().setMessageRB("ERROR_MESSAGE_KEY").setCuase(ex).log();
        }
    }
}

Log message localization

You can use setMessageRB(key) method to specify a key of the specified resource bundle. A log message is going to be like "INFO: Localized message 'arg' (MSG)" in the following example.

Bundle.properties

MSG=Localized message '{0}'

You can use styles both SetMessageRB and logRB. Both methods recognize passed string as a bundle key instead of a message template.

import tokyo.northside.logging.ILogger;
import tokyo.northside.logging.LoggerFactory;

class Example {
    private static final ResourceBundle BUNDLE = ResourceBundle.getBundle("Bundle");

    public static void example() {
        ILogger logger = LoggerFactory.getLogger(Example.class, BUNDLE);

        logger.atInfo().setMessageRB("MSG").addArgument("arg").log();
        logger.atInfo().logRB("MSG", "arg");
    }
}