jd19支持虛擬線程，虛擬線程是輕量級的線程，它們不與操作系統(tǒng)線程綁定，而是由 JVM 來管理。它們適用于“每個請求一個線程”的編程風格，同時沒有操作系統(tǒng)線程的限制。我們能夠創(chuàng)建數(shù)以百萬計的虛擬線程而不會影響吞吐。

做個 springboot demo 嘗試一下。

環(huán)境

• jdk19
• gradle 7.6.1
• IntelliJ IDEA 2022.2.4

build.gradle

plugins {id 'java'id 'org.springframework.boot' version '3.0.3'id 'io.spring.dependency-management' version '1.1.0'
}group = 'com.example'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = '19'configurations {compileOnly {extendsFrom annotationProcessor}
}repositories {mavenCentral()
}dependencies {implementation 'org.springframework.boot:spring-boot-starter'compileOnly 'org.projectlombok:lombok'developmentOnly 'org.springframework.boot:spring-boot-devtools'annotationProcessor 'org.projectlombok:lombok'testImplementation 'org.springframework.boot:spring-boot-starter-test'
}tasks.named('test') {useJUnitPlatform()
}tasks.withType(JavaCompile) {options.compilerArgs += "--enable-preview"
}

多線程demo

寫一段多線程調用的代碼，程序入口

package com.example.myvirtualthreaddemo;import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.task.TaskExecutionAutoConfiguration;
import org.springframework.context.annotation.Bean;
import org.springframework.core.task.AsyncTaskExecutor;
import org.springframework.core.task.support.TaskExecutorAdapter;
import org.springframework.scheduling.annotation.EnableAsync;import java.util.concurrent.Executors;@EnableAsync
@SpringBootApplication
public class MyVirtualThreadDemoApplication {public static void main(String[] args) {SpringApplication.run(MyVirtualThreadDemoApplication.class, args);}@BeanCommandLineRunner commandLineRunner(AsyncService asyncService){return args -> {for(int i = 0; i < 100; i++){asyncService.fun(i);}};}
}

package com.example.myvirtualthreaddemo;import lombok.extern.slf4j.Slf4j;
import org.springframework.scheduling.annotation.Async;
import org.springframework.stereotype.Service;@Service
@Slf4j
public class AsyncService {@Asyncpublic void fun(int i) {log.info("fun:{}", i);}
}

運行結果，使用平臺線程（默認8個）

使用虛擬線程

在MyVirtualThreadDemoApplication添加以下代碼塊

@Bean(TaskExecutionAutoConfiguration.APPLICATION_TASK_EXECUTOR_BEAN_NAME)public AsyncTaskExecutor asyncTaskExecutor(){return new TaskExecutorAdapter(Executors.newVirtualThreadPerTaskExecutor());}

運行結果，使用虛擬線程

遇到的一些問題

請使用 --enable-preview 以啟用預覽 API

解決辦法：

1. build.gradle里添加以下配置：

tasks.withType(JavaCompile) {options.compilerArgs += "--enable-preview"
}

2. 設置vm選項如圖