DataOutputStream os = new DataOutputStream(con.getOutputStream());抛出连接被拒绝异常

Question

我正在尝试将一些数据发布到服务器中。我正在使用在线提供的示例 url。我无法继续前进，因为这条线，

DataOutputStream os = new DataOutputStream(con.getOutputStream());，正在抛出连接被拒绝异常。 这是代码...

public static void main(String[] args) throws Exception {
    try {
        URL url = new URL("https://my-json-server.typicode.com/typicode/demo/posts");
        HttpURLConnection con = (HttpURLConnection) url.openConnection();
        con.setDoOutput(true);
        con.setRequestMethod("POST");
        con.setRequestProperty("Content-Type", "application/json");

        JSONObject jsonObj = new JSONObject();
        jsonObj.put("id", 5);

        DataOutputStream os = new DataOutputStream(con.getOutputStream());
        os.writeBytes(jsonObj.toString());
        os.flush();

        BufferedReader br = new BufferedReader(new InputStreamReader((con.getInputStream())));
        int responseCode = con.getResponseCode();
        String output;
        StringBuffer sb = new StringBuffer();
        System.out.println("Output from Server .... \n");
        while ((output = br.readLine()) != null) {
            sb.append(output);
            break;
        } 

        System.out.println("Response Code: "+responseCode);
        System.out.println("URL: "+url);
        System.out.println("Parameters: "+jsonObj.toString());
        System.out.println("Output: "+output.toString());

        con.disconnect();
    } catch (MalformedURLException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

以下是例外..

java.net.ConnectException: Connection refused: connect
at java.net.DualStackPlainSocketImpl.connect0(Native Method)
at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
at java.net.PlainSocketImpl.connect(Unknown Source)
at java.net.SocksSocketImpl.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at sun.security.ssl.SSLSocketImpl.connect(Unknown Source)
at sun.security.ssl.BaseSSLSocketImpl.connect(Unknown Source)
at sun.net.NetworkClient.doConnect(Unknown Source)
at sun.net.www.http.HttpClient.openServer(Unknown Source)
at sun.net.www.http.HttpClient.openServer(Unknown Source)
at sun.net.www.protocol.https.HttpsClient.<init>(Unknown Source)
at sun.net.www.protocol.https.HttpsClient.New(Unknown Source)
at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.getNewHttpClient(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect(Unknown Source)
at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.getOutputStream(Unknown Source)
at sun.net.www.protocol.https.HttpsURLConnectionImpl.getOutputStream(Unknown Source)
at insertData.main(insertData.java:37)

请帮我解决这个问题。谢谢。

Answer 1

据我所知，您需要将 BufferedReader 更改为 BufferedInputStream 并且“while”循环的构造方式错误，请点击我之前评论中的链接