Spring Boot文档阅读笔记-Creating Asynchronous Methods解析

小鱼儿 2022-10-29 09:25 171阅读 0赞

创建一个GitHub用户信息查找服务，这个服务是通过GitHub的API获取数据的。

接口是http的，如下：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxNzg0NDI3NjE_size_16_color_FFFFFF_t_70][]

这里创建一个model去接收对象：

@Data
    @JsonIgnoreProperties(ignoreUnknown = true)
    public class User {
    
        private String name;
        private String blog;
    }

@JsonIngnore告诉spring忽略其他json属性。

下面是创建GitHub检索服务，代码如下：

@Service
    public class GitHubLookupService {
    
        private static final Logger logger = LoggerFactory.getLogger(GitHubLookupService.class);
        private final RestTemplate restTemplate;
    
        public GitHubLookupService(RestTemplateBuilder restTemplateBuilder){
    
            this.restTemplate = restTemplateBuilder.build();
        }
    
        public CompletableFuture<User> findUser(String user) throws InterruptedException {
    
            logger.info("Looking up " + user);
            String url = String.format("https://api.github.com/users/%s", user);
            User results = restTemplate.getForObject(url, User.class);
            Thread.sleep(1000L);
            return CompletableFuture.completedFuture(results);
        }
    }

GItHubLookupService使用RestTemplate调用api.github.com/users，获取User对象。

AppRunner.java

@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 {
    
            long start = System.currentTimeMillis();
    
            CompletableFuture<User> pivotalSoftware = gitHubLookupService.findUser("PivotalSoftware");
            CompletableFuture<User> cloudFoundry = gitHubLookupService.findUser("CloudFoundry");
            CompletableFuture<User> user = gitHubLookupService.findUser("Spring-Projects");
    
            CompletableFuture.allOf(pivotalSoftware, cloudFoundry, user).join();
    
            logger.info("Elapsed time: " + (System.currentTimeMillis() -  start));
            logger.info("-->" + pivotalSoftware.get());
            logger.info("-->" + cloudFoundry.get());
            logger.info("-->" + user.get());
            logger.info("---------- over ----------");
        }
    }

DemoApplication.java

@SpringBootApplication
    @EnableAsync
    public class DemoApplication {
    
        @Bean
        public Executor taskExecutor(){
    
            ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
            executor.setCorePoolSize(2);
            executor.setMaxPoolSize(2);
            executor.setQueueCapacity(500);
            executor.setThreadNamePrefix("GithubLookup-");
            executor.initialize();
            return executor;
        }
    
        public static void main(String[] args) {
    
            SpringApplication.run(DemoApplication.class, args);
        }
    
    }

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxNzg0NDI3NjE_size_16_color_FFFFFF_t_70]: /images/20221024/c778ca627789428c935e5ee9374db238.png