Spring Boot 2.x版本 + JDK21使用虚拟线程

Spring 3.2原生支持虚拟线程，spring boot 2.x + JDK21再通过手工配置，也能使用上tomcat，如下：

来源：

https://spring.io/blog/2022/10/11/embracing-virtual-threads

config里定义两个类：

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

    @Bean
    public TomcatProtocolHandlerCustomizer<?> protocolHandlerVirtualThreadExecutorCustomizer() {
      return protocolHandler -> {
        protocolHandler.setExecutor(Executors.newVirtualThreadPerTaskExecutor());
      };
    }
}