How to use the logging API framework in the Java library
Use the logging API framework in the Java library
Overview:
Logging API is a commonly used tool in the development of Java programs for recording and managing log information.It provides a unified interface that allows various log implementations in different environments.This article will introduce how to use the logging API framework in the Java library.
Step 1: Import the logging API framework
First, the relevant library files that need to be introduced to the logging API framework.In Java's standard library, there is a package called "Java.util. Logging", which contains related classes and interfaces of Logging API.If you are using other third -party log frames (such as log4j or SLF4J), you need to import these frames of library files accordingly.
For example, use java.util.logging in the Maven project:
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.7.30</version>
</dependency>
Step 2: Create a logger object
In your Java class, you first need to create a logger object to record log information.Under normal circumstances, each class should have a corresponding logger object to better manage the log.
import java.util.logging.Logger;
public class MyClass {
private static final Logger LOGGER = Logger.getLogger(MyClass.class.getName());
public void myMethod() {
LOGGER.info("This is an info message");
LOGGER.warning("This is a warning message");
LOGGER.severe("This is a severe message");
}
}
Step 3: Use Logger to record logs
The Logger object provides multiple methods to record different levels of logs.Common methods include Info (), Warning (), and Severe ().
In the above example, the Logger object is created as a private static constant, and uses the Logger.GetLogger () factory method to obtain the logger object.This method accepts a string parameter for specifying the name of the Logger object. The current class name is usually used as the name.
Then, in the Mymethod () method, we use the logger object to record different levels of log information.The INFO () method is used to record general information messages, the warning () method is used to record warning messages, and the Severe () method is used to record serious error messages.
Step 4: Configure logging API
The default configuration of the Logging API uses the default configuration of JDK to output the log to the standard output stream.But usually we need to configure the log more in detail, such as recording the log into the file, setting the level of the log.
The way to configure the logging API varies from a different log frame.The following is a simple example, demonstrating how to use java.util.logging's log file configuration:
import java.util.logging.ConsoleHandler;
import java.util.logging.FileHandler;
import java.util.logging.Level;
import java.util.logging.Logger;
public class MyLogger {
private static final Logger LOGGER = Logger.getLogger(MyLogger.class.getName());
public void configureLogger() {
try {
// Configure log output to file
FileHandler fileHandler = new FileHandler("mylog.log");
LOGGER.addHandler(fileHandler);
// Set the log level as INFO
LOGGER.setLevel(Level.INFO);
// Set the console output log
ConsoleHandler consoleHandler = new ConsoleHandler();
consoleHandler.setLevel(Level.ALL);
LOGGER.addHandler(consoleHandler);
// Disable the output of Father Logger
LOGGER.setUseParentHandlers(false);
LOGGER.info("Logger is configured successfully.");
} catch (IOException e) {
LOGGER.severe("Failed to configure logger: " + e.getMessage());
}
}
}
In the above code, we output the log into a file called "Mylog.log" by creating a Filehandler object.Then, we set the level of Logger as Info, which means that only the INFO level and above will be recorded.Next, we are equipped with a Consolehandler to output all levels of logs at the console.Finally, by calling Setuseparenthandler (FALSE), the output of the parent Logger was disabled.
You can flexibly configure the logging API according to actual needs to meet different requirements for log management.
Summarize:
This article introduces how to use the logging API framework in the Java library.First, you need to import the related library files of the logging API.Create a logger object to record log information.Finally, the logging API configuration is performed to meet different log management needs.By using Logging API, we can easily record and manage log information of the Java program.
