Android で簡単なログインおよび登録アクティビティを作成しようとしています。エラーが発生しています
結果 java.lang.nullpointerexception の変換中にエラーが発生しました。データ org.json.JSONException の解析中にエラーが発生しました。
以下は私のコードです：JSONPARSER
public class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// constructor
public JSONParser() {
}
// function get json from url
// by making HTTP POST or GET method
public JSONObject makeHttpRequest(String url, String method,
List<NameValuePair> params) {
// Making HTTP request
try {
// check for request method
if(method == "POST"){
// request method is POST
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
httpPost.setEntity(new UrlEncodedFormEntity(params));
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
}else if(method == "GET"){
// request method is GET
DefaultHttpClient httpClient = new DefaultHttpClient();
String paramString = URLEncodedUtils.format(params, "utf-8");
url += "?" + paramString;
HttpGet httpGet = new HttpGet(url);
HttpResponse httpResponse = httpClient.execute(httpGet);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
}
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
json = sb.toString();
} catch (Exception e) {
Log.e("Buffer Error", "Error converting result " + e.toString());
}
// try parse the string to a JSON object
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
// return JSON String
return jObj;
}
}
ユーザー機能:
public class UserFunctions {
private JSONParser jsonParser;
// Testing in localhost using wamp or xampp
// use http://10.0.2.2/ to connect to your localhost ie http://localhost/
private static String loginURL = "http://49.249.85.221/android_api/";
private static String registerURL = "http://49.249.85.221/android_api/";
private static String login_tag = "login";
private static String register_tag = "register";
// constructor
public UserFunctions(){
jsonParser = new JSONParser();
}
/**
* function make Login Request
* @param email
* @param password
* */
public JSONObject loginUser(String email, String password){
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("tag", login_tag));
params.add(new BasicNameValuePair("email", email));
params.add(new BasicNameValuePair("password", password));
String method=new String();
JSONObject json = jsonParser.makeHttpRequest(loginURL,method, params);
// return json
// Log.e("JSON", json.toString());
return json;
}
/**
* function make Login Request
* @param name
* @param email
* @param password
* */
public JSONObject registerUser(String name, String email, String password){
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("tag", register_tag));
params.add(new BasicNameValuePair("name", name));
params.add(new BasicNameValuePair("email", email));
params.add(new BasicNameValuePair("password", password));
String method=new String();
// getting JSON Object
JSONObject json = jsonParser.makeHttpRequest(registerURL,method, params);
// return json
return json;
}
/**
* Function get Login status
* */
public boolean isUserLoggedIn(Context context){
DatabaseHandler db = new DatabaseHandler(context);
int count = db.getRowCount();
if(count > 0){
// user logged in
return true;
}
return false;
}
/**
* Function to logout user
* Reset Database
* */
public boolean logoutUser(Context context){
DatabaseHandler db = new DatabaseHandler(context);
db.resetTables();
return true;
}
}
登録活動:
public class RegisterActivity extends Activity {
Button btnRegister;
Button btnLinkToLogin;
EditText inputFullName;
EditText inputEmail;
EditText inputPassword;
TextView registerErrorMsg;
// JSON Response node names
private static String KEY_SUCCESS = "success";
private static String KEY_ERROR = "error";
private static String KEY_ERROR_MSG = "error_msg";
private static String KEY_UID = "uid";
private static String KEY_NAME = "name";
private static String KEY_EMAIL = "email";
private static String KEY_CREATED_AT = "created_at";
private class MyAsyncTask extends AsyncTask<String, Void, JSONObject> {
protected JSONObject doInBackground(String... params) {
UserFunctions userFunction = new UserFunctions();
if (params.length != 3)
return null;
JSONObject json = userFunction.registerUser(params[0], params[1], params[2]);
return json;
}
protected void onPostExecute(JSONObject json) {
// check for login response
try {
if (json != null && json.getString(KEY_SUCCESS) != null) {
registerErrorMsg.setText("");
String res = json.getString(KEY_SUCCESS);
if(Integer.parseInt(res) == 1){
// user successfully registred
// Store user details in SQLite Database
DatabaseHandler db = new DatabaseHandler(getApplicationContext());
JSONObject json_user = json.getJSONObject("user");
// Clear all previous data in database
UserFunctions userFunction = new UserFunctions();
userFunction.logoutUser(getApplicationContext());
db.addUser(json_user.getString(KEY_NAME), json_user.getString(KEY_EMAIL), json.getString(KEY_UID), json_user.getString(KEY_CREATED_AT));
// Launch Dashboard Screen
Intent dashboard = new Intent(getApplicationContext(), DashboardActivity.class);
// Close all views before launching Dashboard
dashboard.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(dashboard);
// Close Registration Screen
finish();
}else{
// Error in registration
registerErrorMsg.setText("Error occured in registration");
}
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.register);
// Importing all assets like buttons, text fields
inputFullName = (EditText) findViewById(R.id.registerName);
inputEmail = (EditText) findViewById(R.id.registerEmail);
inputPassword = (EditText) findViewById(R.id.registerPassword);
btnRegister = (Button) findViewById(R.id.btnRegister);
btnLinkToLogin = (Button) findViewById(R.id.btnLinkToLoginScreen);
registerErrorMsg = (TextView) findViewById(R.id.register_error);
// Register Button Click event
btnRegister.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
String name = inputFullName.getText().toString();
String email = inputEmail.getText().toString();
String password = inputPassword.getText().toString();
new MyAsyncTask().execute(name, email, password);
UserFunctions userFunction = new UserFunctions();
JSONObject json = userFunction.registerUser(name, email, password);
// check for login response
try {
if (json.getString(KEY_SUCCESS) != null) {
registerErrorMsg.setText("");
String res = json.getString(KEY_SUCCESS);
if(Integer.parseInt(res) == 1){
// user successfully registred
// Store user details in SQLite Database
DatabaseHandler db = new DatabaseHandler(getApplicationContext());
JSONObject json_user = json.getJSONObject("user");
// Clear all previous data in database
userFunction.logoutUser(getApplicationContext());
db.addUser(json_user.getString(KEY_NAME), json_user.getString(KEY_EMAIL), json.getString(KEY_UID), json_user.getString(KEY_CREATED_AT));
// Launch Dashboard Screen
Intent dashboard = new Intent(getApplicationContext(), DashboardActivity.class);
// Close all views before launching Dashboard
dashboard.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(dashboard);
// Close Registration Screen
finish();
}else{
// Error in registration
registerErrorMsg.setText("Error occured in registration");
}
}
} catch (JSONException e) {
e.printStackTrace();
}
}
});
// Link to Login Screen
btnLinkToLogin.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
Intent i = new Intent(getApplicationContext(),
LoginActivity.class);
startActivity(i);
// Close Registration View
finish();
}
});
}
}
デバッガーを実行するとif (json.getString(KEY_SUCCESS) != null)
、RegisterActivity の行が示されました。どこが間違っているのか、私にはわかりません。これについて私を案内してください。
ログキャット:
10-28 22:40:27.422: D/dalvikvm(373): GC_EXTERNAL_ALLOC freed 78K, 52% free 2599K/5379K, external 897K/1038K, paused 190ms
10-28 22:40:32.000: W/KeyCharacterMap(373): No keyboard for id 0
10-28 22:40:32.000: W/KeyCharacterMap(373): Using default keymap: /system/usr/keychars/qwerty.kcm.bin
10-28 22:40:45.879: E/Buffer Error(373): Error converting result java.lang.NullPointerException
10-28 22:40:45.899: E/Buffer Error(373): Error converting result java.lang.NullPointerException
10-28 22:40:45.983: E/JSON Parser(373): Error parsing data org.json.JSONException: End of input at character 0 of
10-28 22:40:45.989: D/AndroidRuntime(373): Shutting down VM
10-28 22:40:45.989: W/dalvikvm(373): threadid=1: thread exiting with uncaught exception (group=0x40015560)
10-28 22:40:46.049: E/AndroidRuntime(373): FATAL EXCEPTION: main
10-28 22:40:46.049: E/AndroidRuntime(373): java.lang.NullPointerException
10-28 22:40:46.049: E/AndroidRuntime(373): at com.example.androidhive.RegisterActivity$1.onClick (RegisterActivity.java:112)
10-28 22:40:46.049: E/AndroidRuntime(373): at android.view.View.performClick(View.java:2485)
10-28 22:40:46.049: E/AndroidRuntime(373): at android.view.View$PerformClick.run(View.java:9080)
10-28 22:40:46.049: E/AndroidRuntime(373): at android.os.Handler.handleCallback(Handler.java:587)
10-28 22:40:46.049: E/AndroidRuntime(373): at android.os.Handler.dispatchMessage(Handler.java:92)
10-28 22:40:46.049: E/AndroidRuntime(373): at android.os.Looper.loop(Looper.java:123)
10-28 22:40:46.049: E/AndroidRuntime(373): at android.app.ActivityThread.main(ActivityThread.java:3683)
10-28 22:40:46.049: E/AndroidRuntime(373): at java.lang.reflect.Method.invokeNative(Native Method)
10-28 22:40:46.049: E/AndroidRuntime(373): at java.lang.reflect.Method.invoke(Method.java:507)
10-28 22:40:46.049: E/AndroidRuntime(373): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run (ZygoteInit.java:839)
10-28 22:40:46.049: E/AndroidRuntime(373): at c om.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
10-28 22:40:46.049: E/AndroidRuntime(373): at dalvik.system.NativeStart.main(Native Method)
10-28 22:40:46.309: E/JSON Parser(373): Error parsing data org.json.JSONException: End of input at character 0 of
10-28 22:40:50.289: I/Process(373): Sending signal. PID: 373 SIG: 9
マーティンが提案した解決策を実装した後、主な問題は解決されました。現在、他のエラーに直面しています。LOGCAT を以下に添付します。
10-28 23:17:19.183: D/dalvikvm(449): GC_EXTERNAL_ALLOC freed 78K, 52% free 2599K/5379K, external 897K/1038K, paused 232ms
10-28 23:17:23.259: W/KeyCharacterMap(449): No keyboard for id 0
10-28 23:17:23.269: W/KeyCharacterMap(449): Using default keymap: /system/usr/keychars/qwerty.kcm.bin
10-28 23:17:46.379: E/Buffer Error(449): Error converting result java.lang.NullPointerException
10-28 23:17:46.389: E/Buffer Error(449): Error converting result java.lang.NullPointerException
10-28 23:17:46.389: E/JSON Parser(449): Error parsing data org.json.JSONException: End of input at character 0 of
10-28 23:17:46.409: E/JSON Parser(449): Error parsing data org.json.JSONException: End of input at character 0 of