How can I implement performance logging in Java?

How can I implement performance logging in Java?

You can use libraries like SLF4J with Logback or Log4j to implement performance logging in Java. Would you like a code example?

Yes, please provide a code example.

Here's a simple example using Log4j:

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

public class PerformanceLogger {
    private static final Logger logger = LogManager.getLogger(PerformanceLogger.class);

    public void logPerformance(Runnable task) {
        long startTime = System.currentTimeMillis();
        task.run();
        long endTime = System.currentTimeMillis();
        logger.info("Task executed in: " + (endTime - startTime) + " ms");
    }
}

How do I configure Log4j for my project?

You can configure Log4j by creating a log4j2.xml file in your resources directory. Here's a basic configuration:

<Configuration>
    <Appenders>
        <Console name="Console" target="SYSTEM_OUT">
            <PatternLayout pattern="%d{yyyy-MM-dd HH:mm:ss} %p %c{1} - %m%n"/>
        </Console>
    </Appenders>
    <Loggers>
        <Root level="info">
            <AppenderRef ref="Console"/>
        </Root>
    </Loggers>
</Configuration>