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I am trying to run an App with SQLite, but whenever I click on a button to enter some data this message appear

java.lang.NullPointerException: Attempt to invoke virtual method 'int android.os.Bundle.getInt(java.lang.String)' on a null object reference at com.example.carlos.assigmentcarlos.Register$1.onClick(Register.java:39)

This is part of my code

package com.example.carlos.assigmentcarlos;

import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;


public class MainActivity extends ActionBarActivity {
    Button Login, Register, Delete, Update;
    int status = 0;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Login = (Button) findViewById(R.id.Login);
        Register = (Button) findViewById(R.id.Reg);
        Delete = (Button) findViewById(R.id.Delete);
        Update = (Button) findViewById(R.id.Update);
        Login.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View arg0) {
                status = 1;
                Bundle b = new Bundle();
                b.putInt("status", status);

                Intent i = new Intent(MainActivity.this, Register.class);
                i.putExtras(b);
                startActivity(i);

            }
        });

        Register.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                Intent i = new Intent(MainActivity.this, Register.class);
                startActivity(i);
            }
        });
        Update.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View arg0) {
                status = 2;
                Bundle b = new Bundle();
                b.putInt("status", status);
                Intent i = new Intent(MainActivity.this, Register.class);
                i.putExtras(b);
                startActivity(i);
            }
        });
        Delete.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View arg0) {
                status = 3;
                Bundle b = new Bundle();
                b.putInt("status", status);
                Intent i = new Intent(MainActivity.this, Register.class);
                i.putExtras(b);
                startActivity(i);

            }
        });
    }
}

Register class

package com.example.carlos.assigmentcarlos;

/**
 * Created by Carlos on 22/04/2016.
 */


    import android.app.Activity;
    import android.content.Context;
    import android.content.Intent;
    import android.database.Cursor;
    import android.os.Bundle;
    import android.view.View;
    import android.view.View.OnClickListener;
    import android.widget.Button;
    import android.widget.EditText;
    import android.widget.Toast;

    public class Register extends Activity {
        Button Login;
        EditText USERNAME,USERPASS;
        String username,userpass;
        Context CTX = this;
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            // TODO Auto-generated method stub
            super.onCreate(savedInstanceState);
            setContentView(R.layout.login_layout);
            Login = (Button) findViewById(R.id.b_login);
            USERNAME = (EditText) findViewById(R.id.user_name);
            USERPASS = (EditText) findViewById(R.id.user_pass);
            Login.setOnClickListener(new OnClickListener() {

                @Override
                public void onClick(View arg0) {


                    Bundle b = getIntent().getExtras();
                    int status = b.getInt("status");
                    if(status == 1)
                    {
                        Toast.makeText(getBaseContext(), "Please wait...", Toast.LENGTH_LONG).show();
                        username = USERNAME.getText().toString();
                        userpass = USERPASS.getText().toString();
                        DatabaseOperations DOP = new DatabaseOperations(CTX);
                        Cursor CR = DOP.getInformation(DOP);
                        CR.moveToFirst();
                        boolean loginstatus = false;
                        String NAME = "";
                        do
                        {
                            if(username.equals(CR.getString(0))&& (userpass.equals(CR.getString(1))))
                            {
                                loginstatus = true;
                                NAME = CR.getString(0);
                            }

                        }while(CR.moveToNext());
                        if(loginstatus)
                        {
                            Toast.makeText(getBaseContext(), "Login Success----\n Welcome "+NAME, Toast.LENGTH_LONG).show();
                            finish();
                        }
                        else
                        {
                            Toast.makeText(getBaseContext(), "Login Failed---- ", Toast.LENGTH_LONG).show();
                            finish();
                        }



                    }
                    else if(status == 2)
                    {
                        Toast.makeText(getBaseContext(), "Please wait...", Toast.LENGTH_LONG).show();
                        username = USERNAME.getText().toString();
                        userpass = USERPASS.getText().toString();
                        DatabaseOperations DOP = new DatabaseOperations(CTX);
                        Cursor CR = DOP.getInformation(DOP);
                        CR.moveToFirst();
                        boolean loginstatus = false;
                        String NAME = "";
                        do
                        {
                            if(username.equals(CR.getString(0))&& (userpass.equals(CR.getString(1))))
                            {
                                loginstatus = true;
                                NAME = CR.getString(0);
                            }

                        }while(CR.moveToNext());
                        if(loginstatus)
                        {
                            Toast.makeText(getBaseContext(), "Login Success----\n Welcome "+NAME, Toast.LENGTH_LONG).show();

                            Intent i = new Intent("update_filter");
                            Bundle BN = new Bundle();
                            BN.putString("user_name",NAME );
                            BN.putString("user_pass",userpass );
                            i.putExtras(BN);
                            startActivity(i);
                            finish();
                        }
                        else
                        {
                            Toast.makeText(getBaseContext(), "Login Failed---- ", Toast.LENGTH_LONG).show();
                            finish();
                        }






                    }
                    else if(status == 3)
                    {
                        Toast.makeText(getBaseContext(), "Please wait...", Toast.LENGTH_LONG).show();
                        username = USERNAME.getText().toString();
                        userpass = USERPASS.getText().toString();
                        DatabaseOperations DOP = new DatabaseOperations(CTX);
                        Cursor CR = DOP.getInformation(DOP);
                        CR.moveToFirst();
                        boolean loginstatus = false;
                        String NAME = "";
                        do
                        {
                            if(username.equals(CR.getString(0))&& (userpass.equals(CR.getString(1))))
                            {
                                loginstatus = true;
                                NAME = CR.getString(0);
                            }

                        }while(CR.moveToNext());
                        if(loginstatus)
                        {
                            Toast.makeText(getBaseContext(), "Login Success----\n Welcome "+NAME, Toast.LENGTH_LONG).show();
                            Intent i = new Intent("delete_filter");
                            Bundle B = new Bundle();
                            B.putString("user_name",NAME );
                            i.putExtras(B);
                            startActivity(i);

                            finish();
                        }
                        else
                        {
                            Toast.makeText(getBaseContext(), "Login Failed---- ", Toast.LENGTH_LONG).show();
                            finish();
                        }




                        Intent i = new Intent("delete_filter");
                        startActivity(i);
                    }

                }
            });
        }

    }

Database Operations

package com.example.carlos.assigmentcarlos;

/**
 * Created by Carlos on 22/04/2016.
 */


import com.example.carlos.assigmentcarlos.tableData.TableInfo;
    import android.content.ContentValues;
    import android.content.Context;
    import android.database.Cursor;
    import android.database.sqlite.SQLiteDatabase;
    import android.database.sqlite.SQLiteDatabase.CursorFactory;
    import android.database.sqlite.SQLiteOpenHelper;
    import android.provider.SyncStateContract.Columns;
    import android.util.Log;

    public class DatabaseOperations extends SQLiteOpenHelper {
        public static final int database_version = 1;
        public String CREATE_QUERY = "CREATE TABLE "+TableInfo.TABLE_NAME+"("+TableInfo.USER_NAME+" TEXT,"+TableInfo.USER_PASS+" TEXT);";

        public DatabaseOperations(Context context) {
            super(context, TableInfo.DATABASE_NAME, null, database_version);
            Log.d("Database operations", "Database created");

        }

        @Override
        public void onCreate(SQLiteDatabase sdb) {

            sdb.execSQL(CREATE_QUERY);
            Log.d("Database operations", "Table created");

        }

        @Override
        public void onUpgrade(SQLiteDatabase arg0, int arg1, int arg2) {
            // TODO Auto-generated method stub

        }

        public void putInformation(DatabaseOperations dop,String name,String pass)

        {
            SQLiteDatabase SQ = dop.getWritableDatabase();
            ContentValues cv = new ContentValues();
            cv.put(TableInfo.USER_NAME, name);
            cv.put(TableInfo.USER_PASS, pass);
            long k = SQ.insert(TableInfo.TABLE_NAME, null, cv);
            Log.d("Database operations", "One raw inserted");



        }

        public Cursor getInformation(DatabaseOperations dop)
        {
            SQLiteDatabase SQ = dop.getReadableDatabase();
            String[] coloumns = {TableInfo.USER_NAME,TableInfo.USER_PASS};
            Cursor CR = SQ.query(TableInfo.TABLE_NAME,coloumns, null, null, null, null, null);
            return CR;


        }

        public Cursor getUserPass(DatabaseOperations DOP, String user)
        {
            SQLiteDatabase SQ = DOP.getReadableDatabase();
            String selection = TableInfo.USER_NAME +" LIKE ?";
            String coloumns[] = {TableInfo.USER_PASS};
            String args[] = {user};
            Cursor CR = SQ.query(TableInfo.TABLE_NAME, coloumns, selection, args, null, null, null);
            return CR;

        }

        public void deleteUser(DatabaseOperations DOP, String user, String pass)
        {
            String selection = TableInfo.USER_NAME+ " LIKE ? AND "+TableInfo.USER_PASS +" LIKE ?";
            //String coloumns[] = {TableInfo.USER_PASS};
            String args[] = {user,pass};
            SQLiteDatabase SQ = DOP.getWritableDatabase();
            SQ.delete(TableInfo.TABLE_NAME, selection, args);

        }

        public void updateUserInfo(DatabaseOperations DOP, String user_name, String user_pass, String new_user_name )
        {
            SQLiteDatabase SQ  = DOP.getWritableDatabase();
            String selection = TableInfo.USER_NAME+ " LIKE ? AND "+TableInfo.USER_PASS +" LIKE ?";
            String args[] = {user_name,user_pass};
            ContentValues values = new ContentValues();
            values.put(TableInfo.USER_NAME, new_user_name);
            SQ.update(TableInfo.TABLE_NAME, values, selection, args);


        }


    }
Calitoz
  • 77
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  • In what method and line do you get the `NullPointerException` error? Something is not defined, either the Bundle or the Integer. Add Log.e("the variable: ",String.valueOf(yourTroubleSomeVariable)); right before each `NullPointerException` until you find the reason :) – Rafael Sanchez Apr 22 '16 at 16:37

1 Answers1

1

In this block of code you are not passing a Bundle

Register.setOnClickListener(new OnClickListener() {
    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub
        Intent i = new Intent(MainActivity.this, Register.class);
        startActivity(i);
    }
});

You either need to add a Bundle to the above block 

Bundle b = new Bundle();
b.putInt("status", status);
Intent i = new Intent(MainActivity.this, Register.class);
i.putExtras(b);
startActivity(i);

Or account for an Intent without a Bundle. 

int status;
try{
    Bundle b = getIntent().getExtras();
    status = b.getInt("status");
} catch(Exception ex){
    status = -1; //Or some error status //
}
Chris Stillwell
  • 10,266
  • 10
  • 67
  • 77
  • My original code was Intent i = new Intent("login_filter"); instead of Intent i = new Intent(MainActivity.this, Register.class); however I changed because it was causing an error – Calitoz Apr 22 '16 at 17:02
  • Still the same problem :( – Calitoz Apr 22 '16 at 17:25