如何从TCP服务器向TCP客户端发送应答?

我有以下服务器和客户端代码。客户机能够成功地将数据发送到服务器,但是当客户机尝试从服务器读取数据时,代码将继续运行而不输出任何数据。

服务器:

public static void main(String[] args) throws Exception {

    ServerSocket s = new ServerSocket(9898);

    while(true) {

        Socket recv = s.accept();

        InputStream inp = recv.getInputStream();
        OutputStream out = recv.getOutputStream();

        String data = null;
        BufferedReader in = new BufferedReader(new InputStreamReader(inp));
        while ( (data = in.readLine()) != null ) {
            System.out.println("\r" + data);
        }

        out.write("sampleSendToClient".getBytes());
    }

}

客户:

public static void main(String[] args) throws Exception{
    Socket clientSocket = new Socket("localhost", 9898);
    OutputStream out = clientSocket.getOutputStream();
    InputStream inp = clientSocket.getInputStream();

    out.write("sampleSendToServer".getBytes());

    String data = null;
    //if I dont write next 4 lines then client exits gracefully 
    //but now it is stuck infinitely
    BufferedReader in = new BufferedReader(new InputStreamReader(inp));
    while ( (data = in.readLine()) != null ) {
        System.out.println("\r" + data);
    }

    clientSocket.close();
}

我无法理解以上代码中的错误。