Hi to all! I made a class named “Database” I called openOrCreateDatabase in in its constructor but it was giving error.
Then I searched on internet and got a solution that in case of non activity class I should also pass context. Then I passed context but then I am facing an error in run time in LogCat: ”java.lang.NullPointerException: Attempt to invoke virtual method 'android.database.sqlite.SQLiteDatabase android.content.Context.openOrCreateDatabase(java.lang.String, int, android.database.sqlite.SQLiteDatabase$CursorFactory)' on a null object reference."
Above in the double quotes is the error.please guide me
Actually I want that I just call the constructor of this class in another class named “InsertRecord” and the database should be created. Now i am pasting code of both my classes
package com.hatflabs.addressbook;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.support.design.widget.TabLayout;
import android.text.Editable;
import android.util.Log;
import android.view.LayoutInflater;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import javax.xml.parsers.FactoryConfigurationError;
/**
* Created by applezone on 1/1/01.
*/
public class Database {
SQLiteDatabase db;
Connection con;
String dbName = "MyDb";
// constructor
public Database(Context ctxt, SQLiteDatabase db) {
db = ctxt.openOrCreateDatabase(dbName, ctxt.MODE_PRIVATE,null);
}
}
Now I am code of InsertRecord class
package com.hatflabs.addressbook;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
import com.hatflabs.addressbook.Database.*;
import java.sql.PreparedStatement;
public class InsertRecord extends AppCompatActivity {
Context ctxt;
SQLiteDatabase db;
Button b1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_insert_record);
b1 = (Button)findViewById(R.id.button1);
b1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//creating object of Database class
Database dtbs = new Database(ctxt,db );
Log.w("Saboor","database created");
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_insert_record, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}