Spring Boot教程（十）异步方法测试

测试

测试代码如下：

@Component
public class AppRunner implements CommandLineRunner {

    private static final Logger logger = LoggerFactory.getLogger(AppRunner.class);

    private final GitHubLookupService gitHubLookupService;

    public AppRunner(GitHubLookupService gitHubLookupService) {
        this.gitHubLookupService = gitHubLookupService;
    }

    @Override
    public void run(String... args) throws Exception {
        // Start the clock
        long start = System.currentTimeMillis();

        // Kick of multiple, asynchronous lookups
        Future<User> page1 = gitHubLookupService.findUser("PivotalSoftware");
        Future<User> page2 = gitHubLookupService.findUser("CloudFoundry");
        Future<User> page3 = gitHubLookupService.findUser("Spring-Projects");

        // Wait until they are all done
        while (!(page1.isDone() && page2.isDone() && page3.isDone())) {
            Thread.sleep(10); //10-millisecond pause between each check
        }

        // Print results, including elapsed time
        logger.info("Elapsed time: " + (System.currentTimeMillis() - start));
        logger.info("--> " + page1.get());
        logger.info("--> " + page2.get());
        logger.info("--> " + page3.get());
    }

}

启动程序，控制台会打印：

2017-04-30 13:11:10.351 INFO 1511 — [ GithubLookup-1] com.forezp.service.GitHubLookupService : Looking up PivotalSoftware
2017-04-30 13:11:10.351 INFO 1511 — [ GithubLookup-2] com.forezp.service.GitHubLookupService : Looking up CloudFoundry
2017-04-30 13:11:13.144 INFO 1511 — [ GithubLookup-2] com.forezp.service.GitHubLookupService : Looking up Spring-Projects

耗时：3908

分析：可以卡的前面2个方法分别在GithubLookup-1 和GithubLookup-2执行，第三个在GithubLookup-2执行，注意因为在配置线程池的时候最大线程为2.如果你把线程池的个数为3的时候，耗时减少。

如果去掉@Async，你会发现，执行这三个方法都在main线程中执行。耗时总结，如下：

2017-04-30 13:13:00.934 INFO 1527 — [ main] com.forezp.service.GitHubLookupService : Looking up PivotalSoftware
2017-04-30 13:13:03.571 INFO 1527 — [ main] com.forezp.service.GitHubLookupService : Looking up CloudFoundry
2017-04-30 13:13:04.865 INFO 1527 — [ main] com.forezp.service.GitHubLookupService : Looking up Spring-Projects

源码来源