无法连接到端口 80

Question

单击登录按钮后，仅显示“尝试登录”消息，应用程序中没有进一步的活动，单击按钮后，LOGCAT 中显示异常“java.net.ConnectException: failed to connect to /127.0.0.1 (port 80) after 15000ms: isConnected failed: ECONNREFUSED (Connection denied)"。可能只是预执行正在运行，而不是后台任务。但问题出在哪里？

登录.java--->

public class Login extends Activity {
        AutoCompleteTextView UsernameEt;
        EditText PasswordEt;
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_login);
            UsernameEt = (AutoCompleteTextView) findViewById(R.id.email);
            PasswordEt = (EditText) findViewById(R.id.password);
        }

        class PostAsync extends AsyncTask<String, String, JSONObject> {
            JSONParser jsonParser = new JSONParser();

            private ProgressDialog pDialog;

           // private static final String LOGIN_URL = "http://10.0.3.2:8080/login3.php";
           // private static final String LOGIN_URL = "http://192.168.*.*/login3.php";
           private static final String LOGIN_URL = "http://127.0.0.1/login3.php";

            private static final String TAG_SUCCESS = "success";
            private static final String TAG_MESSAGE = "message";


            @Override
            protected void onPreExecute() {
                pDialog = new ProgressDialog(Login.this);
                pDialog.setMessage("Attempting login...");
                pDialog.setIndeterminate(false);
                pDialog.setCancelable(true);
                pDialog.show();
            }

            @Override
            protected JSONObject doInBackground(String... args) {

                try {

                    HashMap<String, String> params = new HashMap<>();
                    params.put("name", args[0]);
                    params.put("password", args[1]);

                    Log.d("request", "starting");

                    JSONObject json = jsonParser.makeHttpRequest(
                            LOGIN_URL, "POST", params);

                    if (json != null) {
                        Log.d("JSON result", json.toString());

                        return json;
                    }

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

                return null;
            }

            protected void onPostExecute(JSONObject json) {

                int success = 0;
                String message = "";

                if (pDialog != null && pDialog.isShowing()) {
                    pDialog.dismiss();
                }

                if (json != null) {
                    Toast.makeText(Login.this, json.toString(),
                            Toast.LENGTH_LONG).show();

                    try {
                        success = json.getInt(TAG_SUCCESS);
                        message = json.getString(TAG_MESSAGE);
                    } catch (JSONException e) {
                        e.printStackTrace();
                    }
                }

                if (success == 1) {
                    Log.d("Success!", message);
                }else{
                    Log.d("Failure", message);
                }
            }

        }

        public void OnLogin(View view) {
            String username = UsernameEt.getText().toString();
            String password = PasswordEt.getText().toString();

            new PostAsync().execute(username, password);

        }
    }

………………………………………………………………………………………………………………………………………………………… ...................... JsonParser.java---->

public class JSONParser {

    String charset = "UTF-8";
    HttpURLConnection conn;
    DataOutputStream wr;
    StringBuilder result;
    URL urlObj;
    JSONObject jObj = null;
    StringBuilder sbParams;
    String paramsString;

    public JSONObject makeHttpRequest(String url, String method,
                                      HashMap<String, String> params) {

        sbParams = new StringBuilder();
        int i = 0;
        for (String key : params.keySet()) {
            try {
                if (i != 0){
                    sbParams.append("&");
                }
                sbParams.append(key).append("=")
                        .append(URLEncoder.encode(params.get(key), charset));

            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            }
            i++;
        }

        if (method.equals("POST")) {
            // request method is POST
            try {
                urlObj = new URL(url);

                conn = (HttpURLConnection) urlObj.openConnection();

                conn.setDoOutput(true);

                conn.setRequestMethod("POST");

                conn.setRequestProperty("Accept-Charset", charset);

                conn.setReadTimeout(10000);
                conn.setConnectTimeout(15000);

                conn.connect();

                paramsString = sbParams.toString();

                wr = new DataOutputStream(conn.getOutputStream());
                wr.writeBytes(paramsString);
                wr.flush();
                wr.close();

            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        else if(method.equals("GET")){
            // request method is GET

            if (sbParams.length() != 0) {
                url += "?" + sbParams.toString();
            }

            try {
                urlObj = new URL(url);

                conn = (HttpURLConnection) urlObj.openConnection();

                conn.setDoOutput(false);

                conn.setRequestMethod("GET");

                conn.setRequestProperty("Accept-Charset", charset);

                conn.setConnectTimeout(15000);

                conn.connect();

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

        }

        try {
            //Receive the response from the server
            InputStream in = new BufferedInputStream(conn.getInputStream());
            BufferedReader reader = new BufferedReader(new InputStreamReader(in));
            result = new StringBuilder();
            String line;
            while ((line = reader.readLine()) != null) {
                result.append(line);
            }

            Log.d("JSON Parser", "result: " + result.toString());

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

        conn.disconnect();

        // try parse the string to a JSON object
        try {
            jObj = new JSONObject(result.toString());
        } catch (JSONException e) {
            Log.e("JSON Parser", "Error parsing data " + e.toString());
        }

        // return JSON Object
        return jObj;
    }
}