Null Pointer Exception while connecting to database

Question

I am doing SqlDatabase connectivity through android without using webservice.

I have following two functions in my connection clasxs:

    public class gaSQLConnect 
{
    String url ="";
    Connection conn=null;
    Statement statement=null;
    ResultSet resultSet=null;
        public void setConnection(String DBName,String UserName,String Password)
        {
            try {
                Class.forName("net.sourceforge.jtds.jdbc.Driver").newInstance();
                url ="jdbc:jtds:sqlserver://10.0.2.2:1433;instanceName=14GRAFICALI\\MSSQLSERVER2008;DatabaseName="+DBName+";integratedSecurity=true;user="+UserName+";password="+Password;
                conn =DriverManager.getConnection(url);
                } catch (Exception e) {
                e.printStackTrace();
                }
        }
        public Boolean CheckUser(String uName,String password)
        {
            int recFound=0;

            try
            {
                statement=conn.createStatement();


                resultSet=statement.executeQuery("select * from UserMaster where username="+uName+" and password="+password+"");
                if(resultSet.last())
                {
                    if(resultSet.getRow()>0)
                    {
                        recFound=1;
                    }
                    else
                    {
                        recFound=0;
                    }
                }


            }
            catch (Exception e) {
                e.printStackTrace();
                recFound=0;
            }
            if(recFound==0)
            return false;
            else
                return true;
}
}

I am calling these functions through following code:

final gaSQLConnect con=new gaSQLConnect();

        btnLogin.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View arg0) {
                // TODO Auto-generated method stub

                con.setConnection("AndroidDB", "sa", "ok");
                boolean isValidUser=con.CheckUser(etLoginID.getText().toString(), etPassword.getText().toString());
                if(isValidUser)
                {
                    Intent i= new Intent(getApplicationContext(),Messages.class);
                    startActivity(i);
                }

            }
        });

I debugged app and came to know that exception is on following line:

resultSet=statement.executeQuery("select * from UserMaster where username="+uName+" and password="+password+"");

Logcat:

09-11 11:14:05.896: E/AndroidRuntime(756): FATAL EXCEPTION: main
09-11 11:14:05.896: E/AndroidRuntime(756): java.lang.NullPointerException
09-11 11:14:05.896: E/AndroidRuntime(756):  at com.example.messagesql.gaSQLConnect.CheckUser(gaSQLConnect.java:49)
09-11 11:14:05.896: E/AndroidRuntime(756):  at com.example.messagesql.Login$1.onClick(Login.java:37)
09-11 11:14:05.896: E/AndroidRuntime(756):  at android.view.View.performClick(View.java:2485)
09-11 11:14:05.896: E/AndroidRuntime(756):  at android.view.View$PerformClick.run(View.java:9080)
09-11 11:14:05.896: E/AndroidRuntime(756):  at android.os.Handler.handleCallback(Handler.java:587)
09-11 11:14:05.896: E/AndroidRuntime(756):  at android.os.Handler.dispatchMessage(Handler.java:92)
09-11 11:14:05.896: E/AndroidRuntime(756):  at android.os.Looper.loop(Looper.java:123)
09-11 11:14:05.896: E/AndroidRuntime(756):  at android.app.ActivityThread.main(ActivityThread.java:3683)
09-11 11:14:05.896: E/AndroidRuntime(756):  at java.lang.reflect.Method.invokeNative(Native Method)
09-11 11:14:05.896: E/AndroidRuntime(756):  at java.lang.reflect.Method.invoke(Method.java:507)
09-11 11:14:05.896: E/AndroidRuntime(756):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
09-11 11:14:05.896: E/AndroidRuntime(756):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
09-11 11:14:05.896: E/AndroidRuntime(756):  at dalvik.system.NativeStart.main(Native Method)

@prijupaul its inbuilt method to create statement, as we do con.open() in .net — C Sharper
– C Sharper, Commented Sep 11, 2013 at 5:55
@Shrimant. Just realized that from the docs. So had to delete my comment. — prijupaul
– prijupaul, Commented Sep 11, 2013 at 5:56

J. Steen · Accepted Answer · 2013-09-29 07:59:45Z

2

I think you missed the single quote.

The query should be:

("select * from UserMaster where username='"+uName+"' and password='"+password+" ");

edited Sep 29, 2013 at 7:59

J. Steen

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answered Sep 11, 2013 at 5:57

gbl

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