import com.jcabi.log.Logger;
public class MyClass {
private static final Logger LOGGER = Logger.getLogger(MyClass.class);
public void doSomething() {
LOGGER.info("Something is being done.");
}
}
In the above code, a log recorder called "MyClass" was created using the `GetLogger` method.In the `dosomething` method, a message can be recorded using the` Logger` object.
3. Record log message
In the class library, you can use the following method to record the log message:
-DEBUG: Used to record debugging information.
-Trace: Used to record detailed tracking information.
-INFO: Used to record general information.
-WARN: Used to record warning information.
-ERROR: Used to record error information.
The following is an example code that uses the JCABI LOG framework to record different levels of logs:
import com.jcabi.log.Logger;
public class MyClass {
private static final Logger LOGGER = Logger.getLogger(MyClass.class);
public void doSomething() {
LOGGER.debug("This is a debug message.");
LOGGER.info("This is an info message.");
LOGGER.warn("This is a warning message.");
LOGGER.error("This is an error message.");
}
}
By using the appropriate log level, the details of the log output can be controlled.
Fourth, configuration log framework
The JCABI LOG framework uses SLF4J for log output.You need to add corresponding SLF4J implementation (such as logback, log4j, etc.) in the project.Through the configuration of SLF4J, you can define attributes such as the goals of log output (such as files, consoles, etc.) and log levels.
The following is an example configuration file (logback.xml) implemented using logback as a SLF4J implementation:
<configuration>
<appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
<encoder>
<pattern>%-4relative [%thread] %-5level %logger{35} - %msg%n</pattern>
</encoder>
</appender>
<root level="INFO">
<appender-ref ref="STDOUT" />
</root>
</configuration>
In the above configuration, the log is output to the console, and the log level is set to the INFO level.
5. Add log parameters
The JCABI LOG framework supports adding parameters to the log message.You can specify the position of the parameter by using the parentheses and parameter indexes in the log message string.Then, when recording log messages, you can pass the actual value of the parameter through the `Args` method.The following is an example:
import com.jcabi.log.Logger;
public class MyClass {
private static final Logger LOGGER = Logger.getLogger(MyClass.class);
public void doSomething(String name, int age) {
LOGGER.info("User {0} is {1} years old.", name, age);
}
}
In the above code, the {0} and {1} in the log message represent the position of the first and second parameters, respectively.In the `dosomething` method, the actual value of the parameter can be transferred through the second parameter of the` logger.info` method.
6. Use logs abnormal
You can use the log abnormal object when recording the error log.The JCABI LOG framework provides an abnormal class called `Loggerexception`, which is used for packaging and recording abnormalities.The following is an example:
import com.jcabi.log.Logger;
import com.jcabi.log.LoggerException;
public class MyClass {
private static final Logger LOGGER = Logger.getLogger(MyClass.class);
public void doSomething() {
try {
// Some code that throws an exception
} catch (Exception e) {
LOGGER.error("An error occurred.", new LoggerException(e));
}
}
}
In the above examples, use the `LoggeRexception` to pass the abnormal object to the` Logger.error` method to record and output.
Summarize:
Using the JCABI LOG framework can easily implement the logging function.In the development of the Java class library, you can use the JCABI LOG framework according to the following best practice:
1. Add JCABI LOG dependencies.
2. Create a log recorder.
3. Use the appropriate log level to record log messages.
4. Configure SLF4J implementation.
5. Use parameters in log messages.
6. Use the log of an abnormal record of the wrong log.
By following these best practices, you will be able to use the JCABI LOG framework in the Java class library more efficiently for log records, and can better track and debug applications.
