Microprofile Metrics API: The measurement index collection tool in the Java class library
Microprofile Metrics API is a Java class library for collecting and displaying the measurement indicators of applications.The measurement index is a quantitative measurement of the operating status or performance of the application, which can help developers understand the behavior, positioning problems and optimization performance of the application.
Microprofile Metrics API provides a set of annotations and classes to define and record measures.Here are some commonly used annotations and class examples:
1. @Countid annotation is used to record the number of calls.You can add it to the method, and the counter is increased when each method is called.
@Counted(name = "myMethodCalls")
public void myMethod() {
// Method body
}
2. @Timed annotation is used to record the execution time.You can add it to the method. Each method executes the timer and the execution time will be recorded.
@Timed(name = "myMethodExecutionTime")
public void myMethod() {
// Method body
}
3. @gauge annotation is used to record the values of a certain attribute or variable.It can be added to the attribute or variable, and the value is returned when the measurement index is obtained.
@Gauge(name = "myProperty")
private int myProperty;
The above example is only a small part of the function provided by the Microprofile Metrics API.In addition, more annotations and classes can be used to collect other types of measurement indicators, such as memory use, thread pool status, HTTP request response time, and so on.
Using Microprofile Metrics API needs to add corresponding dependencies to the project.The following is a maven example:
<dependencies>
<dependency>
<groupId>org.eclipse.microprofile.metrics</groupId>
<artifactId>microprofile-metrics-api</artifactId>
<version>2.2.1</version>
</dependency>
</dependencies>
Once the dependencies are added, you can use annotations to define and record the index in the application.These measurement indicators can be obtained and displayed by using Metrics injection.
@Inject
private Metrics metrics;
public void showMetrics() {
Counter counter = metrics.counter("myMethodCalls");
System.out.println("Method Calls: " + counter.getCount());
Timer timer = metrics.timer("myMethodExecutionTime");
System.out.println("Method Execution Time: " + timer.getTime());
Gauge<Integer> gauge = metrics.register("myProperty", () -> myProperty);
System.out.println("Property Value: " + gauge.getValue());
}
Microprofile Metrics API provides a simple and scalable way to collect and display the application of the application.It can help developers quickly understand the operation of the application and perform targeted optimization and debugging.
