Detailed explanation of log levels and filters in the Lumberjack framework
Detailed explanation of log levels and filters in the Lumberjack framework
Lumberjack is a Java log library that provides rich features to manage and record the log of applications.This article will focus on the log level and filter in the LUMBERJACK framework.
1. Log level
Log levels are used to classify and filter log messages at different levels of severity.Lumberjack framework defines the following commonly used log levels:
-Trace: Provide detailed debugging information, suitable for tracking the internal execution process of the application.
-DEBUG: For debugging and development, provide detailed information about application behavior.
-INFO: Provide updates of conventional information and applications.
-WARN: Used to warn messages, indicating potential problems or errors, but it does not cause applications to terminate.
-ERROR: Indicates errors or abnormalities, and may affect the normal operation of the application.
You can determine which level of log messages that can be determined by setting the log level.For example, setting the log level to Debug will enable the log message records of Debug, Info, Warn, and ERROR levels.
Below is a Java code example using Lumberjack framework to record logs:
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class MyClass {
private static final Logger logger = LoggerFactory.getLogger(MyClass.class);
public static void main(String[] args) {
logger.trace("This is a trace message");
logger.debug("This is a debug message");
logger.info("This is an info message");
logger.warn("This is a warn message");
logger.error("This is an error message");
}
}
2. Filter
The filter is used to filter or record log messages according to specific conditions.The Lumberjack framework provides a powerful filter function, allowing developers to customize the processing of logs according to the needs.
Filters can be used in different levels of log messages, including package names, claims, and method names.The Lumberjack framework contains several built -in filter types, such as::
-LEVELFILTER: Filter -based filters can filter log messages according to level.
-LoggerNamefilter: Filters based on the name of the log recorder can filter the log message according to the specified recorder name.
-MessageFilter: Filters based on log message content can filter log messages based on the specified text content.
-THRESHOLDFILTER: Set the threshold of the log level. When it reaches or exceeds the specified level, the log message will be recorded.
The following is an example of the Java code of the filter through the Lumberjack framework:
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class MyClass {
private static final Logger logger = LoggerFactory.getLogger(MyClass.class);
public static void main(String[] args) {
// Set the filter
ch.qos.logback.classic.filter.LevelFilter levelFilter = new ch.qos.logback.classic.filter.LevelFilter();
levelFilter.setLevel("WARN");
// Apply a filter
ch.qos.logback.core.read.CyclicBufferAppender appender = new ch.qos.logback.core.read.CyclicBufferAppender();
appender.addFilter(levelFilter);
// Apply the filter to Logger
ch.qos.logback.classic.Logger loggerImpl = (ch.qos.logback.classic.Logger) logger;
loggerImpl.addAppender(appender);
Logger.debug ("This is a Debug message"); // This news will not be recorded
Logger.warn ("This is a warn message"); // This message will be recorded
logger.error ("This is an error message"); // This message will be recorded
}
}
Through the above example, we created a levelilter and applied it to the logger.In this way, only the log of the warn level and above will be recorded.DEBUG -level messages will be filtered out and will not be recorded.
Summarize:
The Lumberjack framework provides flexible log records and filtering functions. Developers can configure log levels according to the needs of the application and use a filter to filter the log message.These functions help simplify the application of the application and the processing process of the application and improve the efficiency in the development process.
