java - 使用 HTTPUrlConnection 时出现 StackOverflowError

Question

我在使用 HTTPUrlConnection 时遇到一些问题。该代码基本上在循环中运行，每次连接到不同的 URL，检查响应，如果响应满足某些条件则退出。我收到 StackOverflowError，但我不确定我搞砸了什么。我尝试不使用 connection.disconnect() 但无济于事。

另外，你们对加快下面的代码有什么建议吗？

谢谢

Exception in thread "main" java.lang.StackOverflowError at java.security.AccessController.doPrivileged(Native Method) at java.net.Socket.getInputStream(Socket.java:911) at sun.net.www.http.HttpClient.parseHTTP(HttpClient.java:642) at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1535) at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1440) at java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:480) at Main.sendRequest(Main.java:96) at Main.handleResponse(Main.java:140)

public class Main {
    static int counter;

    public static void main(String [] args) {
        counter = 0;
        sendRequest("http://192.168.0.1");
    }

    public static void sendRequest(String path) {
        try {
            URL url = new URL(path);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setRequestMethod("GET");
            connection.connect();

            if (connection.getResponseCode() == HttpURLConnection.HTTP_OK) {
                InputStreamReader inputStreamReader = new InputStreamReader(connection.getInputStream());

                BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
                StringBuilder stringBuilder = new StringBuilder();
                String line = null;
                while ((line = bufferedReader.readLine()) != null) {
                    stringBuilder.append(line);
                }

                String response = stringBuilder.toString();
                handleResponse(response);
                inputStreamReader.close();
                bufferedReader.close();
            }
            connection.disconnect();

        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static void handleResponse(String response) {
        String s = response.substring(62,67);
        if (s.equals("Statu")) {
            return;
        } else {
            sendRequest("http://192.168.0.1/" + counter);
            counter += 1;
        }
    }
}

Answer 1

StackOverflowError 表示您的 sendRequest 递归方法调用已被频繁发送，并且堆栈上没有剩余内存。有关详细解释，请参阅 What is a StackOverflowError?首先，您应该检查一下破坏外观的地方(在 handleResponse 和 sendRequest 中)是否完全按照您的预期工作。尤其是在 handleResponse 中> 看起来是有线的。如果一切正常，您可以尝试重写逻辑以使用循环而不是递归调用。