Introduction to the Metrics Core framework in the Java Class Library

The Metrics Core framework is an open source framework for measurement and monitoring the performance of Java applications.It provides a set of simple and easy -to -use tools to help developers collect key application indicators and display it to users.Metrics Core aims to provide a lightweight and scalable way to measure and report the performance data of the application. When using Metrics Core, you first need to define the required indicators in the application.Metrics Core provides many built -in indicators, such as counter, timer, histogram, etc.Developers can choose the type of indicators suitable for their own application scenarios, and declare and use them in the code. The following is an example that shows how to use the Metrics Core framework to create a counter: import com.codahale.metrics.Counter; import com.codahale.metrics.MetricRegistry; public class MyApp { private static final MetricRegistry registry = new MetricRegistry(); private static final Counter requestsCounter = registry.counter("requests"); private void processRequest() { // Treat the code of the request RequestScounter.inc (); // See a request to increase the value of the counter } public static void main(String[] args) { MyApp app = new MyApp(); // When the application starts, you can register Metricregition // This way Metrics Core will start collecting and reporting index data // This process can be completed by configuration file or code // Metrics Core supports multiple reporters, such as the console reporter, CSV file reporter, JMX reporter, etc. // Here is only the example code of the console reporter ConsoleReporter reporter = ConsoleReporter.forRegistry(registry) .convertRatesTo(TimeUnit.SECONDS) .convertDurationsTo(TimeUnit.MILLISECONDS) .build(); reporter.start(1, TimeUnit.SECONDS); while (true) { // Processing the cycle of request app.processRequest(); } } } The counter in the above example adds its value when processing requests.By registering Metricregition and starting the console reporter, we can regularly check the value of the counter and other related indicators on the console. The Metrics Core framework also provides other types of indicators, such as the execution time of the measured method for measurement methods, the histogram used for statistical data distribution.Developers can choose appropriate indicator types according to their needs, and use the Metrics Core framework to easily measure and report performance data. All in all, the Metrics Core framework is a powerful and easy -to -use tool that helps developers to measure and monitor the performance of Java applications in real time.It provides many built -in indicators and reporters, enabling developers to easily collect and display key performance indicators.Whether it is developing new applications or optimizing existing applications, Metrics Core is a useful framework tool.