由於釋出系統需要上傳修改過後的配置檔案到伺服器上，但是由於Jenkins的客戶端上傳檔案的功能我暫時還沒有研究出來，所以在Jenkins伺服器上寫一個Java指令碼，監聽埠，來獲取上傳檔案的socket請求。

指令碼採用最簡單的BIO模型，整個程式只有一個執行緒，也就是主執行緒，負責監聽8088埠，接收到socket連線，直接在死迴圈中，進行檔案處理。

public class SocketServer {

    private ServerSocket serverSocket;
    private String fileName = "application-prod.yml";
    
 
private Integer port;
    private String folder;
    Logger logger = Logger.getLogger("SocketServer");

    public void receive() {
        String path = folder;
        while (true) {
            if (port == null) {
                break;
            }
            System.out.println("--------listen on " + port + "--------");
            
 
try {
                Socket socket = serverSocket.accept();
                System.out.println(socket.getInetAddress() + ":" + socket.getPort());

                InputStream in = socket.getInputStream();
                OutputStream out = new FileOutputStream(path + fileName);
                byte
 
[] bytes = new byte[16 * 1024];

                int count;
                while ((count = in.read(bytes)) > 0) {
                    out.write(bytes, 0, count);
                }
                out.close();
                in.close();

                removeFile(path, fileName);
            } catch (Exception e) {
                System.out.println(e.getMessage());
            }
        }
    }

    private void removeFile(String path, String fileName) throws IOException {
        String line = getFirstLine(path);
        String serviceName = line.substring(2);

        Files.move(Paths.get(path + "/" + fileName),
                Paths.get(path + "/" + serviceName + "/ " + fileName),
                REPLACE_EXISTING);
    }

    public String getFirstLine(String path) throws IOException {
        BufferedReader br = new BufferedReader(new FileReader(path + "/" + fileName));
        String line = br.readLine();
        br.close();
        return line;
    }

   public String initServer(Integer port, String folder) {
        try {
            this.port = port;
            this.folder = folder;
            serverSocket = new ServerSocket(this.port);
            return "success";
        } catch (IOException e) {
            return e.getMessage();
        }
    }

    public static void main(String[] args) {
        SocketServer socketServer = new SocketServer();

        if (args.length == 0) {
            socketServer.logger.log(Level.ALL, "start server");
            System.out.println("This run need two parameters. format: java className [port] [config file folder]");
            return;
        }

        String port = args[0];
        String folder = args[1];
        if (folder.lastIndexOf("/") + 1 != folder.length()) {
            folder = folder + "/";
        }


        String message = socketServer.initServer(Integer.valueOf(port), folder);
        if (message.equals("success")) {
            socketServer.receive();
        }
        System.out.println("server cannot start logically, because " + message);
    }
}

由於運維要求Java服務需要打成jar包，這樣程序可以管理，因為機器上有很多服務，防止其他人誤殺死該程序。

jar -cvf target_jar_name.jar compiled_class_name.class

如果直接執行，會報錯，錯誤資訊 no main manifest attribute, in SocketServer.jar

這是因為 MANIFEST-MF檔案中少了一個引數，直接編輯jar包，在MANIFEST-MF檔案末尾，加上Main-Class: SocketServer

Error: Could not find or load main class SocketServer.jar