如何在Android API級別22上通過POST請求發送JSON原始數據

Question

目前，我正在調試我的Java代碼，如下所示：

public void sign_in(View view) {
    String json = "";

    // The Username & Password
    final EditText em =  (EditText) findViewById(R.id.Username);
    String email = (String) em.getText().toString();
    final EditText pw =  (EditText) findViewById(R.id.Password);
    String password = (String) pw.getText().toString();
    // -----------------------


    JSONObject jsonObject = new JSONObject();
    try {
        HttpResponse response;
        jsonObject.accumulate("email", email);
        jsonObject.accumulate("password", password);
        json = jsonObject.toString();
        URL url = new URL("http://cloudspecinc.herokuapp.com/api/user/login/");
        HttpClient httpClient = new DefaultHttpClient();
        HttpPost httpPost = new HttpPost(url.toURI());
        httpPost.setEntity(new StringEntity(json, "UTF-8"));
        httpPost.setHeader("Content-Type", "application/json");
        httpPost.setHeader("Accept-Encoding", "application/json");
        httpPost.setHeader("Accept-Language", "en-US");
        response = httpClient.execute(httpPost);
        String sresponse = response.getEntity().toString();
    }
    catch (Exception e) {
        Log.d("InputStream", e.getLocalizedMessage());

    } finally {
        /* nothing to do here */
    }

}

我的問題：

1. 如何獲得POST請求的響應？ 它尚未包含在代碼中，因為我不知道如何獲取它。
2. 嚴重的問題：當我單擊“登錄”按鈕時，應用程序始終崩潰。 （注意：它可以在android studio上編譯，但是當我單擊觸發登錄功能的“登錄”按鈕時會崩潰）。

我認為問題是：

1. HttpClient在Android API級別22中已棄用。（Android 5.1 Lollipop API級別22）
2. 代碼出了點問題。

Answer 1

確定，現在我知道了。請求HTTP類型請求必須在AsyncTask上。 不在當前線程上，因為由於網絡線程異常而在異步類上時，它將拋出異常。 我忘記了所謂的異常。 我只是Java的初學者。 因為我不是Java程序員。

以下代碼可幫助他人解決此類問題。

public class REST extends AsyncTask<Void, Void, Void> {
    @Override
    protected Void doInBackground(Void... params) {
        HttpURLConnection urlConnection=null;
        String json = null;
        // The Username & Password
        final EditText em =  (EditText) findViewById(R.id.Username);
        String email = (String) em.getText().toString();
        final EditText pw =  (EditText) findViewById(R.id.Password);
        String password = (String) pw.getText().toString();
        // -----------------------

        try {
            HttpResponse response;
            JSONObject jsonObject = new JSONObject();
            jsonObject.accumulate("email", email);
            jsonObject.accumulate("password", password);
            json = jsonObject.toString();
            HttpClient httpClient = new DefaultHttpClient();
            HttpPost httpPost = new HttpPost("http://cloudspecinc.herokuapp.com/api/user/login/");
            httpPost.setEntity(new StringEntity(json, "UTF-8"));
            httpPost.setHeader("Content-Type", "application/json");
            httpPost.setHeader("Accept-Encoding", "application/json");
            httpPost.setHeader("Accept-Language", "en-US");
            response = httpClient.execute(httpPost);
            String sresponse = response.getEntity().toString();
            Log.w("QueingSystem", sresponse);
            Log.w("QueingSystem", EntityUtils.toString(response.getEntity()));
        }
        catch (Exception e) {
            Log.d("InputStream", e.getLocalizedMessage());

        } finally {
        /* nothing to do here */
        }
        return null;
    }

    @Override
    protected void onPostExecute(Void result) {
        if (result != null) {
            // do something
        } else {
            // error occured
        }
    }
}