I am trying to work on my android project but getting a null pointer exception in my main function.
So, based on the input id, i wish to set the id entered from the editText and retrieve it when i call the get function which will complete my where clause for the condition.
here is my code:
/*—GetSet.java —- */
public class GetSet {
long gwid=0;
public void setId(long id)
{
gwid = id;
}
public long getId()
{
return gwid;
}
}
The following is my MainActivity.java file
public class MainActivity extends Activity {
EditText etGWid;
Button OKbtn;
public final static String EXTRA_MESSAGE = "com.example.myfirstapp.MESSAGE";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
etGWid = (EditText)findViewById(R.id.etGWID);
OKbtn = (Button)findViewById(R.id.OKbtn);
final GetSet obj_getset = null;
final SharedPreferences app_preferences = PreferenceManager.getDefaultSharedPreferences(this);
// Create a shared preferences variable using the SharedPreferenceManager for storing GWids
SharedPreferences.Editor editor = app_preferences.edit(); // We also need a shared preferences editor to handle the shared preference requests
// Call the edit method (library function) to editor variable can edit the key, values.
editor.putInt("47688507", 47688507); // put in the shared preferences values of user GWids and give them a key for retrieval purposes
editor.putInt("1234567", 1234567);
editor.putInt("7654321", 7654321);
editor.commit(); //commit is necessary to save the shared preferences
OKbtn.setOnClickListener(new View.OnClickListener() {
@SuppressWarnings("null")
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
String gwidCheck = etGWid.getText().toString(); //get the value user enters for GWid
if(app_preferences.contains(gwidCheck)) // this will check the stored shared preferences and compare with the value entered
{
Context context = getApplicationContext();
CharSequence text = "Login Successfull";
int duration = Toast.LENGTH_SHORT; //If it exists, then create a toast message for success
//etGWid.setText(""); // make the textbox empty
long setid = Long.parseLong(gwidCheck); // take the string gwid and convert to long
obj_getset.setId(setid); // set the gwid entered
Toast toast = Toast.makeText(context, text, duration);
toast.show();
intentfunction();
}
else
{
Context context = getApplicationContext();
CharSequence text = "Login Failed"; // If doesnt exist, create a toast for fail
int duration = Toast.LENGTH_SHORT;
Toast toast = Toast.makeText(context, text, duration);
toast.show();
}
}
});
}
private void intentfunction()
{
Intent intent = new Intent(this, SelectOptions.class);
//editText = (EditText) findViewById(R.id.editText1);
//editText = new EditText(this);
String message = "TestHello";
intent.putExtra(EXTRA_MESSAGE, message);
startActivity(intent);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
}
Line number 69 is where i get the problem which is the foll line:
obj_getset.setId(setid);
And this is one of a method in MySQLitehelper.java file that is used to retrieve the row based on the id:
public Cursor getRecord(long rowId) throws SQLException
{
Cursor mCursor =
db.query(true, TABLE_NAME, new String[] {COLUMN_ID,
COLUMN_DATE, COLUMN_LOCATION, COLUMN_TIME},
COLUMN_ID + "=" + getset.getId(), null, null, null, null, null);
if (mCursor != null)
{
mCursor.moveToFirst();
}
return mCursor;
}
My Question is, how do I set the value entered by the user so I can get the value and based on that value, I can put the condition in my where clause just like above. Where am I going wrong ?
LogCat
11-29 21:19:22.525: D/AndroidRuntime(10323): Shutting down VM
11-29 21:19:22.525: W/dalvikvm(10323): threadid=1: thread exiting with uncaught exception (group=0x40a70930)
11-29 21:19:22.583: E/AndroidRuntime(10323): FATAL EXCEPTION: main
11-29 21:19:22.583: E/AndroidRuntime(10323): java.lang.NullPointerException
11-29 21:19:22.583: E/AndroidRuntime(10323): at com.example.upd.MainActivity$1.onClick(MainActivity.java:69)
11-29 21:19:22.583: E/AndroidRuntime(10323): at android.view.View.performClick(View.java:4202)
11-29 21:19:22.583: E/AndroidRuntime(10323): at android.view.View$PerformClick.run(View.java:17340)
11-29 21:19:22.583: E/AndroidRuntime(10323): at android.os.Handler.handleCallback(Handler.java:725)
11-29 21:19:22.583: E/AndroidRuntime(10323): at android.os.Handler.dispatchMessage(Handler.java:92)
11-29 21:19:22.583: E/AndroidRuntime(10323): at android.os.Looper.loop(Looper.java:137)
11-29 21:19:22.583: E/AndroidRuntime(10323): at android.app.ActivityThread.main(ActivityThread.java:5039)
11-29 21:19:22.583: E/AndroidRuntime(10323): at java.lang.reflect.Method.invokeNative(Native Method)
11-29 21:19:22.583: E/AndroidRuntime(10323): at java.lang.reflect.Method.invoke(Method.java:511)
11-29 21:19:22.583: E/AndroidRuntime(10323): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
11-29 21:19:22.583: E/AndroidRuntime(10323): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
11-29 21:19:22.583: E/AndroidRuntime(10323): at dalvik.system.NativeStart.main(Native Method)
11-29 21:19:25.702: I/Process(10323): Sending signal. PID: 10323 SIG: 9
Program closes down unexpectedly.
final GetSet obj_getset = null;Well of course you’re getting a nullPointerException; Your obj_getset is defined to be null right there.