Question

public class LoginActivity extends Activity {

EditText uEmail, uPassword;
String emailID, password;
CheckBox chkRememberMe;
JSONObject jsonResponseObject, jsonObject, data;
String url = "";
String jsonResponseString = "";
String accessToken;
SharedPreferences sharedPreferences;
SharedPreferences.Editor editor;
String urlString = " http://192.168.2.17:8000/api/v1/login/?format=json";
Boolean error, success;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_login);
    uEmail = (EditText) findViewById(R.id.edtEmailId);
    uPassword = (EditText) findViewById(R.id.edtPassword);
    chkRememberMe = (CheckBox) findViewById(R.id.chkRememberMe);
    }


public void signUp(View v) {
    startActivity(new Intent(LoginActivity.this, RegisterActivity.class));
}

public void login(View v) {
    Log.e("Login", "clicked");
    emailID = uEmail.getText().toString().trim();
    password = uPassword.getText().toString().trim();
    new LoginTask().execute(emailID, password);

}

class LoginTask extends AsyncTask<String, Integer, String> {
    @Override
    protected String doInBackground(String... params) {
        StringBuilder sb = new StringBuilder();
        emailID = params[0];
        Log.e("email", emailID);
        password = params[1];
        Log.e("Password", password);
        // convert text data to JSON format
        jsonObject = new JSONObject();
        try {
            jsonObject.accumulate("email", emailID);
            jsonObject.accumulate("password", password);

        } catch (Exception ex) {
            Log.e("Parsing error", ex.toString());
        }

        //convert json data to String which have to send
        String jsonStringToPost = jsonObject.toString();
        Log.e("JSON String to post", jsonStringToPost);

        try {
            //sending data to API
            URL url = new URL(urlString);
            HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
            urlConnection.setDoInput(true);
            urlConnection.setDoOutput(true);
            //urlConnection.setChunkedStreamingMode(0);
            urlConnection.setRequestMethod("POST");
            urlConnection.setRequestProperty("Content-Type", "application/json");
            urlConnection.setReadTimeout(15000); //Sets the maximum time to wait for an input stream read to complete before giving up
            urlConnection.setConnectTimeout(15000); //Sets the maximum time in milliseconds to wait while connecting
            OutputStreamWriter out = new OutputStreamWriter(urlConnection.getOutputStream());
            out.write(jsonStringToPost);
            out.flush();
            out.close();
            //getting response
            InputStream inputStream = new BufferedInputStream(urlConnection.getInputStream());
            BufferedReader br = new BufferedReader(new InputStreamReader(inputStream));
            String responseData = br.readLine();
            while (responseData != null) {
                sb.append(responseData);
                responseData = br.readLine();
            }
            br.close();
            urlConnection.disconnect();
        } catch (Exception ex) {
            Log.e("Connection error", ex.toString());
        }
        jsonResponseString = sb.toString();
        return jsonResponseString;
    }

    @Override
    protected void onPostExecute(String s) {
        jsonResponseString = s;
        Log.e("Response String", jsonResponseString);
        try {
            jsonResponseObject = new JSONObject(jsonResponseString);

            if (success = jsonResponseObject.getBoolean("success")) {
                Log.e("Success", String.valueOf(success));
            } else if(error = jsonResponseObject.getBoolean("error")) {
                Log.e("Error", String.valueOf(error));
            }
        } catch (JSONException e) {
            e.printStackTrace();
        }
    }
}
}

这是我的登录页面的代码。点击登录按钮后，系统会调用login()方法。我通过emailId以password格式向{}发送JSON和AsyncTask。在onPostExecute()中，我使用从API收到的JSON响应字符串。我将获得success = true成功登录，error = true无效登录。

在onPostExecute()方法中，我想使用if-else条件检查登录是成功还是失败，但即使提供无效emailID和{{{}后，我也无法执行其他部分1}}。我们不能在password方法中使用if-else吗？

成功登录时的JSON

onPostExecute()

登录失败的JSON

{ 
    "data": 
        { 
            "access_token": "2c1KjajSYDS6kJqzD1wJ1eGZTO2JbC", 
            "token_type": 
            "Bearer", 
            "expires_in": 36000, 
            "refresh_token": "HLYN8H38G2f9wR8doPxKBNDCZ7KFMg", 
            "scope": "read write groups" 
        }, 
    "success": true 
}

Answer 1

我不确定，但也许if作业总是被评估为真，因为作业是合法的，因此你不会到达其他部分？

尝试使用：

@Override
protected void onPostExecute(String s) {
    jsonResponseString = s;
    Log.e("Response String", jsonResponseString);
    try {
        jsonResponseObject = new JSONObject(jsonResponseString);

        if (jsonResponseObject.getBoolean("success")) {
            success = jsonResponseObject.getBoolean("success");
            Log.e("Success", String.valueOf(success));
        } else if(jsonResponseObject.getBoolean("error")) {
            error = jsonResponseObject.getBoolean("error");
            Log.e("Error", String.valueOf(error));
        }
    } catch (JSONException e) {
        e.printStackTrace();
    }
}

Answer 2

正如Karan Mer所说，你在那里放了错误的代码。如果你必须比较，你应该使用＆＃34; ==＆＃34;，而不是赋值运算符＆＃34; =＆＃34;。您还要将响应与＆＃34;成功＆＃34;进行比较。和＆＃34;错误＆＃34;布尔，但你还没有初始化它们，所以它们的价值总是假的。更好的是你只需从响应中检查成功价值，这足够...... 用，替换你的代码，

if (jsonResponseObject.has("success")) {
    success = jsonResponseObject.getBoolean("success");
    Log.e("Success", String.valueOf(success));
} else if(jsonResponseObject.has("error")){
    error = jsonResponseObject.getBoolean("error");
    Log.e("Error", String.valueOf(error));
}

这将确保它是否具有布尔值＆＃34;成功＆＃34;然后只会检查它。理想情况下，在这种情况下，响应应该只有＆＃34;成功＆＃34;值为真或假，并且不需要＆＃34;错误＆＃34;布尔格了。

无法在AsyncTask的onPostExecute（）方法中执行else语句

2 个答案: