第一次正式用 Java，写了一个 Jenkins 插件

public class AliyunOssPublisher extends Builder {

    // ...

    @Override
    public boolean perform(AbstractBuild<?, ?> build, Launcher launcher, BuildListener listener) throws InterruptedException, IOException {
        logger = listener.getLogger();

        AliyunOssServer server = findServerByName(serverName);
        if (server == null) {
            logger.println("未能找到名为 " + serverName + " 的服务配置");
            return false;
        }

        // ...
        if (publish()) {
            logger.println("发布成功");
            logger.println("准备收尾工作");
            try {
                cleanBackup();
                shutdown();
            } catch (Exception e) {
                logger.println(desensitization(e.getMessage()));
            }
            logger.println("收尾完成");
            return true;
        }
        return false;
    }

    private boolean publish() {
        try {
            // ...
            return true;
        } catch (Exception e) {
            // ...
            return false;
        }
    }

    private void cleanBackup() {
        logger.println("开始检查并清理多余备份内容");
        // ...
    }

    public void shutdown() {
        if (client != null && client.sdk != null) {
            client.sdk.shutdown();
        }
    }

    @Extension
    public static final class AliyunOssPublisherDescriptor extends BuildStepDescriptor<Builder> {

        private List<AliyunOssServer> servers = new ArrayList<>();

        public AliyunOssPublisherDescriptor() {
            super(AliyunOssPublisher.class);
            load();
        }

        public AliyunOssServer[] getServers() {
            return servers.toArray(new AliyunOssServer[0]);
        }

        @Override
        public boolean isApplicable(Class<? extends AbstractProject> aClass) {
            return true;
        }

        @Override
        public String getDisplayName() {
            return "发布到阿里云OSS";
        }

        @Override
        public boolean configure(StaplerRequest req, JSONObject formData)
                throws FormException {
            // ...
        }

        public String getLocalFolderDefaultValue() {
            return "${WORKSPACE}/build";
        }

        public ListBoxModel doFillServerNameItems() {
            ListBoxModel m = new ListBoxModel();
            AliyunOssServer[] servers = getServers();
            for (AliyunOssServer server : servers) {
                m.add(server.getName());
            }
            return m;
        }

        public FormValidation doTestConnection(@QueryParameter("endpoint") String endpoint,
                                               @QueryParameter("internal") Boolean internal,
                                               @QueryParameter("bucketName") String bucketName,
                                               @QueryParameter("accessKeyId") String accessKeyId,
                                               @QueryParameter("accessKeySecret") String accessKeySecret) throws Exception {
            AliyunOssClient client = new AliyunOssClient(endpoint, internal, bucketName, accessKeyId, SecretHelper.decrypt(accessKeySecret));
            try {
                client.test();
                return FormValidation.ok("链接成功");
            } catch (Exception e) {
                return FormValidation.error("链接失败:" + e.getMessage());
            }
        }
    }
}