springboot项目启动后do something

第一种方法：

利用CommandLineRunner接口，自定义接口实现类，并用@Component标注。CommandLineRunner接口在spring-boot.jar中，只有一个run方法，可在run方法中写我们的业务逻辑，不管是初始化一些连接还是预热数据。

示例如下：

@Component
@Order(0)
public class ZookeeperConnector implements CommandLineRunner {
    @Value("${server.weight}")
    private int weight;

    @Value("${server.port}")
    private int port;

    @Value("${zookeeper.url}")
    private String zookeeperUrl;

    @Override
    public void run(String... args) throws Exception {
        RetryPolicy retryPolicy = new ExponentialBackoffRetry(1000, 3);
        CuratorFramework client = CuratorFrameworkFactory.newClient(zookeeperUrl, 5000, 3000, retryPolicy);
        client.start();
        String ip = "127.0.0.1";
        String hostAndPort = ip + ":" + port;
        String path = "/server1/" + hostAndPort;
        try {
            if (client.checkExists().forPath(path) != null) {
                client.delete().forPath(path);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        client.create().creatingParentsIfNeeded().withMode(CreateMode.EPHEMERAL)
                .forPath(path, String.valueOf(weight).getBytes(StandardCharsets.UTF_8));
    }
}

第二种方法：