InputStream 之后 OutputStream 不工作

OutputStream not working after InputStream

我对套接字和 J2ME 很陌生,我想创建一个应用程序,它将一些文本发送到服务器(通过套接字)然后接收答复。因此,当我尝试写入输出时,出现异常:

java.net.SocketException: Socket is closed
    at java.net.Socket.getOutputStream(Socket.java:943)
    at server.run(server.java:55)
    at java.lang.Thread.run(Thread.java:748)

这是我的服务器代码(运行() 方法):

public void run() {
        try {
            serverSocket = new ServerSocket(7997);
            while (true) {
                try {
                    Socket socket = serverSocket.accept();
                    System.out.println("connected");
                    InputStream in = socket.getInputStream();
                    String str = readAll(in);
                    in.close();
                    System.out.println(str);
                    JSONParser parser = new JSONParser();
                    JSONObject json = null;
                    json = (JSONObject) parser.parse(str);
                    text = (String) json.get("text");
                    presalt = (String) json.get("salt");
                    keytoCipher = (String) json.get("key2");
                    String presdvig = (String) json.get("key1");
                    sdvig = Long.parseLong(presdvig);
                    //some methods that work with input
                    caesarEncode();
                    ConKey();
                    precipher();
                    base64code();
                    OutputStream outputStream = socket.getOutputStream();
                    outputStream.write(ciphered.getBytes());
                    outputStream.flush();
                    outputStream.close();
                } catch (ParseException | IOException e) {
                    e.printStackTrace();
                }
            }
            //serverSocket.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

这是 J2ME 客户端代码:

try {
                    System.out.println("connected");
                    JSONObject json = new JSONObject();
                   json.put("text", textField.getString());
                   json.put("salt", "defaultsalt");
                   json.put("key1", "228");
                   json.put("key2", "1488");
                    OutputStream out = sc.openOutputStream();
                    out.write(json.toString().getBytes());
                    out.flush();
                    out.close();
                    InputStream in = sc.openInputStream();
                  String str = readAll(in);
                  System.out.println(str);
                    fieldzwei.setString(str);
                } catch (IOException ex) {
                    ex.printStackTrace();
                } catch (JSONException ex) {
                    ex.printStackTrace();
                }

此外,如果我不向服务器发送任何内容,只是在服务器连接时从中发送一条消息,它就可以正常工作。 有什么我可能错的想法吗?

这里的问题是您关闭了 Socket.getInputStream() 返回的 InputStream:

InputStream in = socket.getInputStream();
String str = readAll(in);
in.close();

来自Javadoc of Socket.getInputStream()

Closing the returned InputStream will close the associated socket.

所以执行上面的代码后,你的套接字将被关闭。

tl;dr:如果您仍然需要 OutputStream,请不要关闭 InputStream。