Log4j Version

Introduction to Log4j Version

We have a different version available for Log4j; it is used to control the application’s logging levels. By the use of it, we can modify the logging without being modify the application binaries. Log4j version provides updates and improvements from the last version; it basically comes up with an improvement in performance, flexibility, etc. Log4j now comes with Log4j 2 version with so many improvements. Here we will see more about the Log4j version in detail, with each explained for better understanding and to implement this in our application for better performance and logging activity.

List of Log4j Version

As we already know that Log4j is used to maintain the logs for the application; by using this, we can maintain the logs at a different level, for example: WARN, INFO, DEBUG, and ERROR. If we want our application to print only specific logs to the console after deployment, then we have to mention this in the log4j properties file.

We have a different version available for log4j:

1. Log4j 1

This is nothing but a java-based library that helps us maintain the logging level for the application. We can also enable and disable some logging based on the library, but for this, we have made some configuration in the properties file. Also, this properties file should be placed in the class path of the application. Inside this file, we can mention the configuration we want and make files containing the logs for the application. These things can have managed by the .xml or properties file in the application. But this version of Log4j does not provide flexibility, java logging, and some issue with this framework.

Let’s discuss each version of Log4j 1 in detail:

a. Log4j 1.2: This version of Log4j was launched on 5, august 2015 with some improvements. But this version has some security issue associated with it. It has a socket server that performs serialization and deserialization without performing any checks on the object or without verifying them; this may cause them to a security issue in Log4j, but all these have come over in Log4j 2 version, so they are insisting everyone to move to log4j 2 now which comes up with more flexibility and improve security breaches. Also, it has a compatibility issue with the java version because, in java version 9, we have some algorithm changes, which makes the log4j 1.2 to not work properly with it. But while implementing it, we have to keep in mind these points as well, so they are forcing us to move to log4j 2. Also, logging is important in the application to track the application working and trace error, if any.

Things which does not support by Log4j 1.2 version are as follows:

• It has a security issue with it.
• Does not support the java version due to a change in algorithm.

b. Log4j 1.3: This version has the same problem as Log4j 1.2; also, its development has been no longer carried out. Apache team has not any plan to release this 1.3 version of Log4j. They planned to move these features to Log4j 2 because the features they are trying to implement also being implemented in log4j 1.2, so they cancelled this version to release. So this not in use as of now.

2. Log4j 2

This version of log4j comes into the picture; in this, there have provided so many improvements, including the security issue present in the above version. It also supports different version of java; they have also come up with improved performance; it also supports asynchronous loggers inside this. They will help in higher perforce in a multithreading environment.

Let’s discuss each of the improvement:

• It provides support for asynchronous logging: By using Log4j 2, we can implement asynchronous logging for our application; this will provide us higher performance in a multithreading environment. This was not supported in the log4j library but comes up with an impro in log4j 2 library. Throughput of Asynchronous loggers can be increased in the multithreading setup or environment, we can say. These loggers make effective and better use of the multi-core.
• It has overcome the security issue.
• Support version of java.
• It provides support for the multiple APIS: Log4j 2 provide support for multiple Apies such as common loggings, SLF4J etc.
• Java lambda support: Log4j also comes up with support for lambda in Java 8. For this to evaluate, we have to enable the log4j for our lambda expression in an application.
• Garbage free : It has support for both standalone and web application. The standalone application will be garbage-free, but for a web application, it will have low garbage. If we have less or free garbage, then it will create a low pressure on the garbage collector in java and give us better performance.
• Cloud support : Log4j 2 also provide support for cloud-enabled. By this, we can access the docker container; for this, we have to make a configuration in Log4j.
• Support to use builder api: In Log4j, we can use builder api to create our logs or events.
• We can also customize our logs by using log4j levels.
• In Log4j 2, we also do not require creating the appended pattern or layout because it automatically does this. The reason behind this it uses a plugin to create the component in Log4j 2.

Conclusion

Using Log4j, we can maintain our application logs, which helps us track the error in our application, if any. We can also maintain the logging level for this; we have different logging levels, as we discussed above. But to use them inside our application, we have to have a .xml or properties file in place.

This is a guide to the Log4j Version. Here we discuss the introduction and the list of Log4j version for better understanding. You may also have a look at the following articles to learn more –

1. Java Shutdown Hook
2. Java GUI Framework
3. Java Vector Class
4. Java URL Class