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ログインした情報を共有設定に保存する小さなログインアプリケーションを作成しようとしました。共有環境設定コンテキストエラー
共有設定データを保存して取得してクリアするクラスを作成しました。 クラスはコンテキストを取ります。ログインアクティビティからログインクラスにコンテキストを渡して共有設定にデータを保存すると、エラー。
エラーは、空のコンテキストを渡したことを示します。
これは私のクラスとアクティビティです。
ログイン・アクティビティー
public class LoginActivity extends AppCompatActivity {
EditText lemailtxt,lpasstxt;
Button loginbttn;
String lurl;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
lurl = "http://192.168.1.6/test/test.php";
lemailtxt = (EditText) findViewById(R.id.emailtxt);
lpasstxt = (EditText) findViewById(R.id.passtxt);
loginbttn = (Button) findViewById(R.id.loginbttn);
loginbttn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
MLoginOnline login = new MLoginOnline(getApplicationContext()
,lurl,lemailtxt.getText().toString(),lpasstxt.getText().toString());
login.execute();
}
});
}
ログインクラス
public class MLoginOnline extends AsyncTask<Void,Void,String>{
Context mContext;
String Purl;
String Pemail,Ppass;
ProgressDialog progressDialog;
public MLoginOnline(Context mContext, String purl, String pemail, String ppass) {
this.mContext = mContext;
Purl = purl;
Pemail = pemail;
Ppass = ppass;
}
MySession session = new MySession(mContext);
@Override
protected void onPreExecute() {
super.onPreExecute();
progressDialog = new ProgressDialog(mContext);
progressDialog.setTitle("Login");
progressDialog.setMessage("Loging in please wait......");
progressDialog.show();
}
@Override
protected String doInBackground(Void... params) {
String data = Loginto();
return data;
}
@Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
String id,name,sem;
if (s ==null){
Toast.makeText(mContext,"Error Login in",Toast.LENGTH_SHORT).show();
progressDialog.hide();
}else {
progressDialog.hide();
try {
JSONObject object = new JSONObject(s);
id = object.getString("id");
name = object.getString("name");
sem = object.getString("sem");
session.InPutUser(id,name,Pemail,sem);
Intent intent = new Intent(mContext, HomeActivity.class);
mContext.startActivity(intent);
} catch (JSONException e) {
e.printStackTrace();
}
}
}
private String Loginto(){
InputStream inputStream=null;
String line = null;
try {
URL url = new URL(Purl+"?Email="+Pemail+"&Password="+Ppass);
HttpURLConnection con = (HttpURLConnection) url.openConnection();
inputStream = new BufferedInputStream(con.getInputStream());
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
StringBuffer stringBuffer = new StringBuffer();
if(bufferedReader != null){
while ((line=bufferedReader.readLine()) != null){
stringBuffer.append(line+"\n");
}
}else {
return null;
}
return stringBuffer.toString();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
}
**共有好みクラス**
public class MySession {
Context mcontext;
SharedPreferences preferences;
SharedPreferences.Editor editor;
int PRIVATE_MODE = 0;
private static final String PREFER_NAME = "session";
private final String IS_USER_LOGED_IN = "IsUserLogedIn";
public final String KEY_ID = "id";
public final String KEY_EMAIL = "email";
public static final String KEY_NAME = "name";
public static final String KEY_SEM = "sem";
public MySession(Context mcontext) {
this.mcontext = mcontext;
this.preferences = mcontext.getSharedPreferences(PREFER_NAME,PRIVATE_MODE);
editor = preferences.edit();
}
public void InPutUser(String id,String name,String email,String sem){
editor.putBoolean(IS_USER_LOGED_IN,true);
editor.putString(KEY_ID,id);
editor.putString(KEY_NAME,name);
editor.putString(KEY_SEM,sem);
editor.putString(KEY_EMAIL,email);
editor.commit();
}
public void logoutUser(Context context,Class intent){
// Clearing all user data from Shared Preferences
editor.clear();
editor.commit();
// After logout redirect user to Login Activity
Intent i = new Intent(context, intent);
// Closing all the Activities
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
// Add new Flag to start new Activity
i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
// Staring Login Activity
context.startActivity(i);
}
public HashMap<String, String> getNameAndSem(){
HashMap<String, String> user = new HashMap<String, String>();
// user name
user.put(KEY_NAME, preferences.getString(KEY_NAME, null));
// user email id
user.put(KEY_EMAIL, preferences.getString(KEY_SEM, null));
// return user
return user;
}
public HashMap<String, String> getIDandEMail() {
HashMap<String, String> user = new HashMap<String, String>();
// user name
user.put(KEY_NAME, preferences.getString(KEY_ID, null));
// user email id
user.put(KEY_EMAIL, preferences.getString(KEY_EMAIL, null));
// return user
return user;
}
public boolean IsUserLoggedIn(){
return preferences.getBoolean(IS_USER_LOGED_IN, false);
}
}
猫あなたのsessionフィールドはnullContextで初期化されている
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.zer0ll.demo.studentapp, PID: 20793
java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.SharedPreferences android.content.Context.getSharedPreferences(java.lang.String, int)' on a null object reference
at com.zer0ll.demo.studentapp.MySession.<init>(MySession.java:36)
at com.zer0ll.demo.studentapp.MLoginOnline.<init>(MLoginOnline.java:43)
at com.zer0ll.demo.studentapp.MainView.LoginActivity$1.onClick(LoginActivity.java:32)
at android.view.View.performClick(View.java:5156)
at android.view.View$PerformClick.run(View.java:20755)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:145)
at android.app.ActivityThread.main(ActivityThread.java:5835)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1399)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1194)
Application terminated.
ありがとう、それは今働いて –
あなたは歓迎です... – rafsanahmad007