public String webLogin() {

        String responseData = null;

        OkHttpClient client = new OkHttpClient();

        TextView tvUser = findViewById(R.id.EditTextUser);

        TextView tvPassWord = findViewById(R.id.EditTextPassWord);

        String user = tvUser.getText().toString();

        String passWord = tvPassWord.getText().toString();　　

        RequestBody body = new FormBody.Builder().add("User", user).add("PassWord", passWord).build();

        //请求

        Request request = new Request.Builder().addHeader("Content-Type","application/json;charset=utf-8").url("网址").post(body).build();

        try {

            Response response = client.newCall(request).execute();

            responseData = response.body().string();

        } catch (IOException e) {

            e.printStackTrace();

        }

        return responseData;

    }