kindly help me resolve the error. I am getting this error in Android Studio. I am new to android development. Problem with Registration..not able to insert data into database. The error is:
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.database.Cursor android.database.sqlite.SQLiteDatabase.rawQuery(java.lang.String, java.lang.String[])' on a null object reference
DB_Connectivity
package com.freedomkitchen.sonali.freedomkitchenAndroidApp;
import android.annotation.SuppressLint;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.support.v7.app.ActionBar;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Toast;
import com.freedomkitchen.sonali.freedomkitchenAndroidApp.NewUserWelcome;
import java.util.logging.Handler;
import java.util.logging.LogRecord;
public class DB_Connectivity extends AppCompatActivity {
SQLiteDatabase myDB;
int user_ID;
private static final boolean AUTO_HIDE = true;
private static final int AUTO_HIDE_DELAY_MILLIS = 3000;
private static final int UI_ANIMATION_DELAY = 300;
private final Handler mHideHandler = new Handler() {
@Override
public void close() {
}
@Override
public void flush() {
}
@Override
public void publish(LogRecord record) {
}
};
private View mContentView;
private final Runnable mHidePart2Runnable = new Runnable() {
@SuppressLint("InlinedApi")
@Override
public void run() {
mContentView.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LOW_PROFILE
| View.SYSTEM_UI_FLAG_FULLSCREEN
| View.SYSTEM_UI_FLAG_LAYOUT_STABLE
| View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY
| View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
| View.SYSTEM_UI_FLAG_HIDE_NAVIGATION);
}
};
private View mControlsView;
private final Runnable mShowPart2Runnable = new Runnable() {
@Override
public void run() {
// Delayed display of UI elements
ActionBar actionBar = getSupportActionBar();
if (actionBar != null) {
actionBar.show();
}
mControlsView.setVisibility(View.VISIBLE);
}
};
private boolean mVisible;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
myDB = openOrCreateDatabase("FreedomKitchenDB.db", MODE_PRIVATE, null);
myDB.execSQL("CREATE TABLE IF NOT EXISTS User_Details(User_ID INTEGER PRIMARY KEY," +
"First_Name TEXT,Last_Name TEXT,Gender TEXT ,Age TEXT,Country TEXT);");
myDB.execSQL("CREATE TABLE IF NOT EXISTS Login_Details(User_ID INTEGER," +
"Username TEXT,Password TEXT,FOREIGN KEY(User_ID) REFERENCES User_Details(User_ID));");
}
@Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
}
public void UserLogin(String username,String password) {
myDB.execSQL("Select User_ID from Login_Details where Username=" + username + "and Password=" + password+");");
Cursor cursor_one = myDB.rawQuery("Select * from User_Details", null);
int rows = cursor_one.getCount();
cursor_one.moveToFirst();
if (rows == 0) {
Toast.makeText(getApplicationContext(), "Incorrect Username or Password. Please try again.", Toast.LENGTH_SHORT).show();
} else if (rows == 1) {
Intent i = new Intent(getApplicationContext(), FreedomKitchenMenu.class);
startActivity(i);
}
}
public void Registration(String first_name,String last_name,String age,String gender,String country,String username,String password){
int user_ID=0;
Cursor cursor_one = myDB.rawQuery("Select * from User_Details", null);
int rows = cursor_one.getCount();
cursor_one.moveToFirst();
user_ID=rows+1;
myDB.execSQL("INSERT INTO User_Details(User_ID,User_FirstName,User_LastName,Gender,Age,Country)VALUES("+user_ID+"','"+first_name+"','" + last_name + "','" + gender + "','" + age + "','" + country + ");");
myDB.execSQL("INSERT INTO Login_Details(User_ID,Username,Password)VALUES(" + user_ID + "','" + username+ "','" + password + ");");
Intent i=new Intent(getApplicationContext(),NewUserWelcome.class);
startActivity(i);
}
}
Logcat
04-22 07:58:57.111 31243-31243/? E/Zygote: v2
04-22 07:58:57.121 31243-31243/? E/SELinux: [DEBUG] get_category: variable seinfo: default sensitivity: NULL, cateogry: NULL
04-22 07:59:08.501 31243-31243/com.freedomkitchen.sonali.freedomkitchen E/ViewRootImpl: sendUserActionEvent() mView == null
04-22 07:59:12.971 31243-31243/com.freedomkitchen.sonali.freedomkitchen E/ViewRootImpl: sendUserActionEvent() mView == null
04-22 07:59:33.221 31243-31243/com.freedomkitchen.sonali.freedomkitchen E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.freedomkitchen.sonali.freedomkitchen, PID: 31243
java.lang.IllegalStateException: Could not execute method for android:onClick
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:293)
at android.view.View.performClick(View.java:5076)
at android.view.View$PerformClick.run(View.java:20279)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5910)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1405)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1200)
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288)
at android.view.View.performClick(View.java:5076)
at android.view.View$PerformClick.run(View.java:20279)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5910)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1405)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1200)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.database.Cursor android.database.sqlite.SQLiteDatabase.rawQuery(java.lang.String, java.lang.String[])' on a null object reference
at com.freedomkitchen.sonali.freedomkitchenAndroidApp.DB_Connectivity.Registration(DB_Connectivity.java:122)
at com.freedomkitchen.sonali.freedomkitchenAndroidApp.Registration.Reg(Registration.java:93)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288)
at android.view.View.performClick(View.java:5076)
at android.view.View$PerformClick.run(View.java:20279)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5910)
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:1405)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1200)
Aucun commentaire:
Enregistrer un commentaire