Detailed explanation of the "logging API" framework in the Java class library
Detailed explanation of Java's logging API framework
Overview:
Java's Logging API is the official log framework used in the Java platform to record the application of the application.It provides a simple and flexible method to record various log messages, which can be used for failure elimination, performance tuning, and error analysis.The purpose of Logging API is to help developers better manage log information during application development.
Main components of Logging API:
1. Loggers (Loggers): The log recorder is responsible for actual records and management log messages.Each log message is associated with a specific log recorder. Developers can control the generation and output of log messages by configured different log recorders.
2. Log processor (handlers): The log processor is responsible for output log messages to appropriate goals, such as console, files, databases, etc.Developers can choose the appropriate processor as needed, and configure the output format and level of their log messages.
3. Formatters: The format format defines the output format of the log message.Developers can use the built -in format or custom format to define the display of log messages.
4. Filters: The filter is used to select a specific log message to be recorded.Developers can use filter to achieve logging filtering so that only messages to meet specific conditions can be recorded.
5. Configuration Files: Logging API uses a configuration file to define the behavior of the log system.Developers can configure different attributes as needed, such as log levels, processors, formats, etc.
Logging API use example:
Below is a simple example that shows how to use the logging API to record log messages in Java applications.
First of all, you need to introduce Java's logging library:
import java.util.logging.Logger;
Then, create a logger object:
private static final Logger logger = Logger.getLogger(MyClass.class.getName());
You can now use the logger to record log messages in the code:
Logger.info ("This is a message log message");
logger.warning ("This is a warning log message");
Logger.severe ("This is a serious error log message");
By default, the log message will be exported to the console.In order to output log messages to the file, you can add a Filehandler processor:
import java.util.logging.FileHandler;
import java.util.logging.Level;
public class MyClass {
private static final Logger logger = Logger.getLogger(MyClass.class.getName());
public static void main(String[] args) {
try {
FileHandler fileHandler = new FileHandler("mylogfile.log");
logger.addHandler(fileHandler);
// Set the output level of log message
logger.setLevel(Level.ALL);
Logger.info ("This is a message log message");
logger.warning ("This is a warning log message");
Logger.severe ("This is a serious error log message");
} catch (IOException e) {
e.printStackTrace();
}
}
}
The above code records the log message to a file named "Mylogfile.log", and sets the output level to all levels.Configuration can be performed according to actual needs.
Summarize:
Java's logging API framework provides a flexible and configurable way to record the log message of the application.Developers can use the logging API to manage and record the logs of the application to help failure elimination, performance tuning and error analysis.By using a log processor, format, filter and other components, developers can customize the behavior of the log system as needed.
