Frequently Asked questions using the Akka SLF4J framework in the Java class library
Frequently Asked questions using the Akka SLF4J framework
Akka is an open source toolkit for building a highly concurrent, distributed, and fault -tolerant application.It is very popular with Java developers. Among them, SLF4J (Simple Logging Facade for Java) is one of the log record frameworks commonly used by AKKA.When using the Akka SLF4J framework, developers may encounter some common problems.The following are the answers to these questions and related Java code examples.
Question 1: How to configure the Akka SLF4J framework to output logs?
answer:
The Akka SLF4J framework uses logback as the default log output implementation.To configure the Akka SLF4J framework to output logs, you can create a logback.xml or logback-test.xml file and place it under the application path of the application.This file can specify the configuration of the log, output format, etc. to meet the needs of the application.
The following is the configuration of a sample logback.xml file:
<configuration>
<appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
<encoder>
<pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
</encoder>
</appender>
<root level="DEBUG">
<appender-ref ref="STDOUT" />
</root>
</configuration>
Question 2: How to record logs in the Akka SLF4J framework?
answer:
It is very simple to record logs in the Akka SLF4J framework.You can use the logger class provided by Akka to record logs.The following is an example of using the Akka SLF4J framework to record INFO level logs:
import akka.event.Logging;
import akka.event.LoggingAdapter;
public class MyActor extends AbstractActor {
private final LoggingAdapter log = Logging.getLogger(getContext().getSystem(), this);
@Override
public Receive createReceive() {
return receiveBuilder()
.match(String.class, msg -> {
log.info("Received message: {}", msg);
})
.build();
}
}
In the above example, we use the Akka's logging class to obtain a logger instance, and then we can use this instance to record the log messages of different levels.
Question 3: How to use MDC (Mapped Diagnostic Context) in the Akka SLF4J framework?
answer:
MDC is a function of the SLF4J framework, which can be used to track the context -related data tracking in the log.In the Akka SLF4J framework, MDCs can be used using extended SLF4JLOGER classes.The following is an example that shows how to use MDC in the Akka SLF4J framework:
import akka.event.DiagnosticLoggingAdapter;
import akka.event.Logging;
import akka.event.LoggingAdapter;
public class MyActor extends AbstractActor {
private final LoggingAdapter log = Logging.getLogger(getContext().getSystem(), this);
private final DiagnosticLoggingAdapter diagLog = Logging.withMDC(log);
@Override
public Receive createReceive() {
return receiveBuilder()
.match(String.class, msg -> {
diagLog.setMDC(Collections.singletonMap("key", "value"));
diagLog.info("Received message: {}", msg);
diagLog.clearMDC();
})
.build();
}
}
In the above example, we created a DiagnosticLoggingadapter instance Diaglog, using its SETMDC method to set the MDC key value pair.Then, we can use the DIAGLOG record belt with the log message of the context data, and finally use the ClearMDC method to remove the MDC.
This is the answer to often see questions using the Akka SLF4J framework.By configured correctly and using the Akka SLF4J framework, developers can easily record and manage the log messages of the application.
