JMH generator: the guidelines for the use of the annotation processor in the Java class library
JMH generator: the guidelines for the use of the annotation processor in the Java class library
JMH (Java Microbenchmark Harness) is a powerful tool for micro -foundation testing in the Java class library for micro -standard testing.It allows developers to write, run, and analyze the benchmark tests to evaluate the performance and efficiency of the code.
The annotation processor is a powerful tool in the Java language. It can process the annotation during the compilation and generate a new Java code.Combined with the JMH generator, we can easily use the annotation processor and JMH tools to create the benchmark test.
Here are some common operations and example code when using the JMH generator:
1. Import jmh and JMH generator dependencies
<dependency>
<groupId>org.openjdk.jmh</groupId>
<artifactId>jmh-core</artifactId>
<version>1.32</version>
</dependency>
<dependency>
<groupId>org.openjdk.jmh</groupId>
<artifactId>jmh-generator-annprocess</artifactId>
<version>1.32</version>
</dependency>
2. Create the benchmark test class
import org.openjdk.jmh.annotations.Benchmark;
import org.openjdk.jmh.annotations.Mode;
import org.openjdk.jmh.annotations.Scope;
import org.openjdk.jmh.annotations.State;
import org.openjdk.jmh.runner.Runner;
import org.openjdk.jmh.runner.options.Options;
import org.openjdk.jmh.runner.options.OptionsBuilder;
@State(Scope.Thread)
public class MyBenchmark {
private static final int SIZE = 1000000;
private int[] array;
@Setup
public void setup() {
array = new int[SIZE];
for (int i = 0; i < SIZE; i++) {
array[i] = i;
}
}
@Benchmark
public int testMethod() {
int sum = 0;
for (int i = 0; i < SIZE; i++) {
sum += array[i];
}
return sum;
}
public static void main(String[] args) throws Exception {
Options options = new OptionsBuilder()
.include(MyBenchmark.class.getSimpleName())
.mode(Mode.SampleTime)
.forks(1)
.build();
new Runner(options).run();
}
}
In the above sample code, we created a benchmark test class `Mybenchmark`, which contains a benchmark test method` testmethod`.This method will sum up for an array of integer array containing 10,000,000 elements.In this example, we use the `scope.thread` to mark the status`@state`, indicating that each test thread will have an independent state.
3. Run the benchmark test
Using a combination of the `Options` and` Runner` class, we can create a configuration containing the benchmark test test, and perform the benchmark test by calling the `Run` method.
4. Analysis of the test results
The JMH generator can not only help us run the benchmark test, but also generate detailed test results reports.By analyzing these results reports, we can draw valuable information about the performance and efficiency of the measured code.
Summarize:
This article introduces the guideline of the JMH generator.The JMH generator combines the annotation processor to provide us with a simple and powerful way to write, run and analyze the benchmark test.By using the JMH generator, developers can better evaluate the performance of the code and optimize it.
I hope this article will help you when using the JMH generator and annotation processor!
