Unable to pass string value from one class to another

I am trying to send a string accessed from a spinner, to a data helper class to run a query and insert the value in another spinner which is running on another activity.

NewTask.java:

@Override
public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
    // On selecting a spinner item
    label = spinnerComp.getSelectedItem().toString(); //storing value of spinner in string label
    System.out.println("NewTask label="+label);
    toRetDeptString();   //it will call return string method
    // Showing selected spinner item
    Toast.makeText(spinnerComp.getContext(), "You selected: " + label, Toast.LENGTH_LONG).show();
}

The return string method is also declared in NewTask.java:

public String toRetDeptString() {
    System.out.println("NewTask String label="+label);
    return label;
}

I am trying to access the value of a label string dataHelper class which runs the query on the basis of the value in the string label.

DataHelper.java in DatabaseHelper class:

public List<String> getAllLabelsDept(){
    NewTask a = new NewTask();
    String n1= a.toRetDeptString();  //this one doesn't worked
    // String n1 = a.label;  //this one doesn't worked
    // String n1="umbrella";  //this method worked by directly assiging string value
    System.out.println("a="+n1);
    List<String> labels = new ArrayList<String>();

    //  Query
    String selectQuery = "select  " + Dept + " from "+TABLE_NAME +" where " + Comp + " = '" + n1 +"'";
    SQLiteDatabase db1 = this.getReadableDatabase();
    Cursor cursor = db1.rawQuery(selectQuery, null);

    // looping through all rows and adding to list
    if (cursor.moveToFirst()) {
        do {
            labels.add(cursor.getString(cursor.getColumnIndex(Dept)));
        } while (cursor.moveToNext());
    }

    // closing connection
    cursor.close();
    db1.close();

    // returning labels
    return labels;
}

Select_Dept.java:

public class Select_Dept extends Activity implements OnItemSelectedListener{
    Spinner spinnerDept;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_select__dept);
        spinnerDept = (Spinner) findViewById(R.id.spinnerDept);
        spinnerDept.setOnItemSelectedListener(this);
        loadSpinnerDataDept();
    }

    private void loadSpinnerDataDept() {
        // database handler
        DatabaseHelper db = new DatabaseHelper(getApplicationContext());
        // Spinner Drop down elements
        List<String> lables = db.getAllLabelsDept();
        // Creating adapter for spinner
        ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, lables);
        // Drop down layout style - list view with radio button
        dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        // attaching data adapter to spinner
        spinnerDept.setAdapter(dataAdapter);
    }

    @Override
    public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
        // On selecting a spinner item
        String label = spinnerDept.getSelectedItem().toString();
        // Showing selected spinner item
        Toast.makeText(spinnerDept.getContext(), "You selected: " + label, Toast.LENGTH_LONG).show();
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.select__dept, menu);
        return true;
    }

    @Override
    public void onNothingSelected(AdapterView<?> arg0) {
        // TODO Auto-generated method stub
    }
}

Logcat:

- 06-05 12:30:13.369: I/ActivityManager(59): Starting activity: Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10200000 cmp=com.EzyCloud.ezytask/.MainActivity }
- 06-05 12:30:14.160: I/ActivityManager(59): Displayed activity com.EzyCloud.ezytask/.MainActivity: 562 ms (total 562 ms)
- 06-05 12:30:16.139: I/ActivityManager(59): Starting activity: Intent { cmp=com.EzyCloud.ezytask/.NewTask }
- 06-05 12:30:16.299: I/System.out(280): NewTask label=umbrella
- 06-05 12:30:16.299: I/System.out(280): NewTask String label=umbrella
- 06-05 12:30:16.559: I/ActivityManager(59): Displayed activity com.EzyCloud.ezytask/.NewTask: 406 ms (total 406 ms)
- 06-05 12:30:19.140: I/ActivityManager(59): Starting activity: Intent { cmp=com.EzyCloud.ezytask/.Select_Dept }
- 06-05 12:30:19.339: I/System.out(280): NewTask String label= //no value accesed
- 06-05 12:30:19.339: I/System.out(280): a=                     **//no value accesed**
- 06-05 12:30:19.699: I/ActivityManager(59): Displayed activity  - com.EzyCloud.ezytask/.Select_Dept: 508 ms (total 508 ms)
- 06-05 12:30:24.849: D/dalvikvm(128): GC_EXPLICIT freed 202 objects / 9800 bytes in 145ms

But the string is not accessed.

First, when you get

System.out(280): NewTask String label= //no value accesed

the NewTask instance didn't in stack top.

Second, the variable label is a private variable, so it is possible to not exist.

If you want to get label, you could use static. Example: public static label;, but I don't suggest for you to do like this, because this is dangerous.

Finally, you could build a customizable Application class and private String label; to record the label (overall) or pass the label through intent.