Java HTTP 请求偶尔挂起

Question

在大多数情况下，我的 HTTP 请求都没有问题。但是，它们偶尔会挂起。

我使用的代码设置为如果请求成功(响应代码为 200 或 201)，则调用 screen.requestSucceeded()。如果请求失败，则调用 screen.requestFailed()。

然而，当请求挂起时，它会在调用上述方法之一之前挂起。我的代码有问题吗？我是否应该使用某种最佳实践来防止挂起？

以下是我的代码。我将不胜感激任何帮助。谢谢!

HttpConnection connection = (HttpConnection) Connector.open(url
                    + connectionParameters);

            connection.setRequestMethod(method);
            connection.setRequestProperty("WWW-Authenticate",
                    "OAuth realm=api.netflix.com");
            if (method.equals("POST") && postData != null) {
            connection.setRequestProperty("Content-Type",
                    "application/x-www-form-urlencoded");
            connection.setRequestProperty("Content-Length", Integer
                    .toString(postData.length));
            OutputStream requestOutput = connection.openOutputStream();
            requestOutput.write(postData);
            requestOutput.close();
        }
            int responseCode = connection.getResponseCode();
            System.out.println("RESPONSE CODE: " + responseCode);
            if (connection instanceof HttpsConnection) {
                HttpsConnection secureConnection = (HttpsConnection) connection;
                String issuer = secureConnection.getSecurityInfo()
                        .getServerCertificate().getIssuer();
                UiApplication.getUiApplication().invokeLater(
                        new DialogRunner(
                                "Secure Connection! Certificate issued by: "
                                        + issuer));

            }

            if (responseCode != 200 && responseCode != 201) {
                screen.requestFailed("Unexpected response code: "
                        + responseCode);
                connection.close();
                return;
            }

            String contentType = connection.getHeaderField("Content-type");
            ByteArrayOutputStream baos = new ByteArrayOutputStream();

            InputStream responseData = connection.openInputStream();
            byte[] buffer = new byte[20000];
            int bytesRead = 0;
            while ((bytesRead = responseData.read(buffer)) > 0) {
                baos.write(buffer, 0, bytesRead);
            }
            baos.close();
            connection.close();
            screen.requestSucceeded(baos.toByteArray(), contentType);
        } catch (IOException ex) {
            screen.requestFailed(ex.toString());
        }

Answer 1

没有任何痕迹，我只是在黑暗中拍摄。

尝试添加这 2 个调用，

System.setProperty("http.keepAlive", "false");

connection.setRequestProperty("Connection", "close");

保持 Activity 状态是连接失效的常见原因。这些调用将禁用它。