Java 9 Platform Logging API and Service

Java

215

java9

12

platform

2

logging

8

service

3

loveprogramming viết ngày 19/05/2021

I. Platform Logging API and Service

An implementation of LoggerFinder is loaded with help of java.util.ServiceLoader API using system class loader. Basing on this implementation, an application/framework can plug in its own external logging backend, without configuring java.util.logging or that backend.

We can pass the class name or module (related to specific Logger) to the LoggerFinder so that the LoggerFinder can know which logger to return.

public class MyLoggerFinder extends LoggerFinder {

    @Override
    public Logger getLogger(String name, Module module) {
        // return Logger depending on name/module...
    }
}

If no concrete implementation is found, JDK default LoggerFinder implementation will be used. java.util.logging (in java.logging module) now becomes backend. So log messages will be routed to java.util.logging.Logger.

We obtain loggers that are created from the LoggerFinder using factory methods of the System class:

package java.lang;
...
public class System {
    System.Logger getLogger(String name) { ... }
    System.Logger getLogger(String name, ResourceBundle bundle) { ... }
}

II. Example

1. Overview

In logger package:

• We will create 2 concrete Loggers that implement Logger interface: MyLogger and MyNewLogger.
• MyLoggerFinder is an implementation of LoggerFinder that can return desired Logger by name. We build logger package into demo.logging module. This module provides an implementation of LoggerFinder service.

In app packagee, we create a Test Class that uses System factory method getLogger(name) to get Loggers and use them.
We build app package into demo.app module.

Folder tree should be:

More at:

https://grokonez.com/java/java-9/java-9-platform-logging-and-service

Java 9 Platform Logging API and Service