NumberFormatException in Android

Question

I'm making an application in which the user can add Store departments and for those departments the ability to add the cities of where the departments are located.

I keep on getting a NumberFormatException when I'm trying to add a city for a departement:

Caused by: java.lang.NumberFormatException: Invalid long: "null"
            at java.lang.Long.invalidLong(Long.java:124)
            at java.lang.Long.parseLong(Long.java:345)
            at java.lang.Long.parseLong(Long.java:321)
            at org.hello.addgroups.vestiging_list.onCreate(vestiging_list.java:45)

after this the app crashes but when I restart the app the values are added into the list.

these are my classes: Add_vestiging.java:

public class Add_vestiging extends Activity implements View.OnClickListener{

EditText et,hiddenet;
Button add_bt, cancel_btn;
SQLController dbcon;
Intent i;
Long groupd;

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.add_new_vestiging);
    et = (EditText)findViewById(R.id.vestigingName);
    add_bt = (Button) findViewById(R.id.addBtn);
    cancel_btn = (Button) findViewById(R.id.cancelBtn);

    dbcon = new SQLController(this);
    try {
        dbcon.open();
    } catch(SQLException e) {
        e.printStackTrace();
    }
    i = getIntent();
    String id = i.getStringExtra("groupID");
    groupd = Long.parseLong(id);
    add_bt.setOnClickListener(this);
    cancel_btn.setOnClickListener(this);
}

@Override
public void onClick(View v) {
        switch(v.getId()) {
            case R.id.addBtn:
                String name = et.getText().toString();
                try {
                    dbcon.insertVestiging(groupd, name);
                }catch(SQLiteException e) {
                    e.printStackTrace();
                }
                Intent main = new Intent(Add_vestiging.this, vestiging_list.class);
                startActivity(main);
                break;
            case R.id.cancelBtn:
                super.finish();
                break;

        }
}
}

vestiging_list.java:

public class vestiging_list extends Activity {

        ListView lv;
        SQLController dbcon;
        TextView title;
        Button addves;
        Long long_id;
        String groupid;
        Intent add_ves;
        String groupname;
        protected void onCreate(Bundle savedInstanceState) {
                super.onCreate(savedInstanceState);
                setContentView(R.layout.vestiging_list);
                dbcon = new SQLController(this);
                title = (TextView) findViewById(R.id.vestitel);


                try {
                        dbcon.open();
                } catch (SQLException e) {
                        e.printStackTrace();
                }
                add_ves = getIntent();
                groupid = add_ves.getStringExtra("groupID");
                groupname = add_ves.getStringExtra("groupName");
                title.setText(groupname);
                long_id = Long.parseLong(groupid);

                addves = (Button)findViewById(R.id.addves_bt_id);
                lv = (ListView)findViewById(R.id.vestigingList_id);

                addves.setOnClickListener(new View.OnClickListener() {
                        @Override
                        public void onClick(View v) {

                                add_ves = new Intent(getApplicationContext(), Add_vestiging.class);
                                add_ves.putExtra("groupID", groupid);
                                startActivity(add_ves);
                        }
                });

                Cursor cursor = dbcon.readVestigingen(long_id);
                String[] from = new String[] { GroupDatabaseHelper.V_ID, GroupDatabaseHelper.VESNAME};
                int[] to = new int [] { R.id.vesID, R.id.vesName};

                SimpleCursorAdapter adapter = new SimpleCursorAdapter(vestiging_list.this, R.layout.vestiging_single_row_item, cursor, from, to,1);
                adapter.notifyDataSetChanged();
                lv.setAdapter(adapter);

                     }
}

Any ideas on how to remove the NumberFormatException? Any help is greatly appreciated.

Thanks in advance.

Answer 1

Any ideas on how to remove the NumberFormatException?

The exception is caused by Long.parseLong in vestiging_list at line 45. The reason is that groupid, in your case in null. Since you didn't fill up the Intent object you used to start vestiging_list.

E.g.

case R.id.addBtn:
      String name = et.getText().toString();
      try {
         dbcon.insertVestiging(groupd, name);
       }catch(SQLiteException e) {
          e.printStackTrace();
       }
    Intent main = new Intent(Add_vestiging.this, vestiging_list.class);
    main.putExtra("groupID", String.valueOf(groupd));
    startActivity(main);
    break;

assuming that groupd is a long.