java IOUtils复制和写入问题

Question

我试图从客户端向服务器发送字符串，但它似乎没有从输入流中读取

客户

Scanner scanner = new Scanner(System.in);
Socket connection = new Socket("localhost", 13)
OutputStream out = connection.getOutputStream();

while(true) {
    String message = scanner.nextLine();
    IOUtils.write(message, out, "UTF-8");
    out.flush();
}

服务器

ServerSocket server = new ServerSocket(localhost,13);~
Socket connection = server.accept();
InputStream in = connection.getInputStream();
StringWriter writer = new StringWriter();

while(true) {
    try {
        IOUtils.copy(in, writer);
        System.out.println(writer.toString());
    } catch(IOException io) {}
}

如果我从客户机的outputstream关闭流，但我试图从客户机向服务器发送多条消息，它就会读取。有人能帮忙吗