templates.plugins.spincast-logback-utils.spincast-logback-utils.html Maven / Gradle / Ivy
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{% extends "../../layout.html" %}
{% block sectionClasses %}plugins hasBreadCrumb plugins-spincast-logback-utils{% endblock %}
{% block meta_title %}Plugins - Spincast Logback Utils{% endblock %}
{% block meta_description %}Spincast Logback Utils plugin - Logback easy configuration{% endblock %}
{% block scripts %}
{% endblock %}
{% block body %}
Plugins- Spincast Logback Utils plugin
Overview
Logback is one of the most popular logger implementations
for Java. It works very well with the SLF4J logging facade
which is used by Spincast itself.
A challenge with a regular installation of Logback is to configure it
differently on each environment. For example to specify a
DEBUG level for logs during development but a WARN level in production.
Logback does provide a way to do some kind of conditional processing of configuration files
but this involves an untyped syntax using a third-party library and requires
passing extra command line arguments or setting extra environment variables.
This plugin provides an easy way to configure Logback, fully integrated
with Spincast: you use Java code, with dependency injection support,
and you can:
-
Specify the path to the configuration file Logback should use. For example
"
logback-dev.xml", "logback-acc.xml" or "logback-prod.xml",
depending on some logic.
-
Tweak the content of the
XML configuration file, for example by replacing some
placeholders before Logback is configured.
Finally, if required, this plugin also allows you to dynamically generate the
configurations to be used by Logback, without even requiring a configuration
file at all!
Usage
Default behavior
When you add this plugin to your application, the default behavior is similar to
including Logback as a regular dependency: a logback.xml file will be
looked for on the classpath and its content will be used as is.
Logback Configurer
To get control over how Logback is configured, you need to bind a custom implementation
of SpincastLogbackConfigurerConfig.
You can extends SpincastLogbackConfigurerConfigDefault
as a base for your implementation.
In this implementation, you can specify:
-
ResourceInfo getResourceInfo()
The path to the XML Logback configuration file to use.
You can use any logic you need to pick the correct file. For example,
you may choose a logback-dev.xml file during development and
a logback-prod.xml file otherwise:
{% verbatim %}
@Override
public ResourceInfo getResourceInfo() {
String path = getAppConfig().isDevelopmentMode() ? "/config/logback-dev.xml" :
"/config/logback-prod.xml";
return new ResourceInfo(path, true);
}
{% endverbatim %}
By returning an instance of ResourceInfo, you
specify if the path you provide refers to a file on the classpath or on the file system.
Note that you can also return null here! By doing so, you are responsible to
provide the full XML configuration, as a String, in the tweakContent(...)
method.
-
String tweakContent(String logbackContent)
This method allows you to modify the content of the configurations as loaded using
the getResourceInfo() method.
If you return null from getResourceInfo(),
you will receive an empty String and you are responsible to build the entire
XML configurations for Logback.
A common usage of this method is to replace some placeholders in the
base XML content. For example, let's say the content of the file is:
{% verbatim %}
<?xml version="1.0" encoding="UTF-8"?>
<configuration>
<appender name="stdout" class="ch.qos.logback.core.ConsoleAppender">
<encoder>
<charset>UTF-8</charset>
<pattern>%d{yyyy-MM-dd HH:mm:ss} [%level] %msg ~ %caller{1}</pattern>
</encoder>
</appender>
<root level="{{LEVEL}}">
<appender-ref ref="stdout"/>
</root>
</configuration>
You could use tweakContent(...) to replace the {{LEVEL}} placeholder using logic such as:
@Override
public String tweakContent(String logbackContent) {
String level = getAppConfig().isDevelopmentMode() ? "debug" : "warn";
return logbackContent.replace("{{LEVEL}}", level);
}
{% endverbatim %}
Note that you could also use the Templating Engine
here to replace such placeholders!
Your SpincastLogbackConfigurerConfig implementation will be automatically used by
the SpincastLogbackConfigurer
component that the plugin will bind using asEagerSingleton().
Because of this, Logback is going to be configured very early during the application startup.
Installation
1.
Add this Maven artifact to your project:
<dependency>
<groupId>org.spincast</groupId>
<artifactId>spincast-plugins-logback-utils</artifactId>
<version>{{spincast.spincastCurrrentVersion}}</version>
</dependency>
2. Add an instance of the SpincastLogbackUtilsPlugin
plugin to your Spincast Bootstrapper:
{% verbatim %}
Spincast.configure()
.plugin(new SpincastLogbackUtilsPlugin())
// ...
{% endverbatim %}
{% endblock %}
Spincast Logback Utils 
Spincast Logback Utils