使用Java Servlet通過HTTP請求發送字符串

Question

嗨，我正在嘗試實現一個服務器，該服務器接受一個字符串，然后生成並向客戶端返回另一個字符串，但是運行不正常。

這是我嘗試過的：服務器：

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    ....
    String str = "something";

    // Return the queueId.
    OutputStreamWriter writer = new OutputStreamWriter(response.getOutputStream());
    writer.write(str);
    writer.flush();
    writer.close();
}

客戶：

    String URL = "http://localhost:8080/"
    String serverURL = URL + "servlet?param=" + someParam;
    final URL url = new URL(serverURL)
    final URLConnection connection = url.openConnection();
    connection.setDoOutput(true);

    final BufferedReader br = new BufferedReader(new InputStreamReader(connection.getInputStream()));

    System.out.println(br.readLine());

但是br.readLine（）以某種方式返回null。 在這種情況下哪一方錯？

提前致謝。

Answer 1

您的客戶應進行以下更改。 由於您使用的是doPOST而不是doGet

String URL = "http://localhost:8080/"
String serverURL = URL + "servlet?param=" + someParam;
final URL url = new URL(serverURL)
final HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoOutput(true);
connection.setRequestMethod("POST");

final BufferedReader br = new BufferedReader(new InputStreamReader(connection.getInputStream()));

System.out.println(br.readLine());

您的代碼可能正在調用doGet