few columns data is not inserting in the sqlite database, android

in my application few columns data is not inserting in Sqlite Database, I was checked for many time for the error but am unable to find the problem, So am posting here. help me with the solution

AddTask.class

    String activity_name = null, activity_description = null,
            activity_startTime = null, time_Duration = null,
            activity_startDate = null, activity_endDate = null,
            activity_day = null, activity_status = null;

    public void addTask(View v) {
        activity_name = etAddTask.getText().toString();
        time_Duration = spnDuration.getSelectedItem().toString();
        DataBaseHandler db = new DataBaseHandler(this);
        db.addContact(new Contact(activity_name, activity_description,
                activity_startTime, time_Duration, activity_startDate,
                activity_endDate, activity_day, activity_status));
        //Toast.makeText(getApplicationContext(), "duration is "+duration, Toast.LENGTH_SHORT).show();
        Intent i = new Intent(getApplicationContext(), Excercise.class);
        i.putExtra("Categorie Name", categorie_Name);
        i.putExtra("User_Name", user_name);

        startActivity(i);

    }

here spnDuration is a spinner containing some times intervals.

DataBaseHandler.class

 public void CreateTable(String className)
        {
            SQLiteDatabase db=this.getWritableDatabase();
            if(className=="Excercise")
            {
            String CREATE_CONTACTS_TABLE = "CREATE TABLE IF NOT EXISTS " + TABLE_CONTACTS + "("
                    + ACTIVITY_ID + " INTEGER PRIMARY KEY," + ACTIVITY_NAME + " TEXT,"
                    + ACTIVITY_DESCRIPTION + " TEXT," + ACTIVITY_STARTTIME + " TEXT," + DURATION + " TEXT," + ACTIVITY_STARTDATE + " TEXT," 
                    + ACTIVITY_ENDDATE + " TEXT," + ACTIVITY_DAY + " TEXT," + ACTIVITY_STATUS + " TEXT" + ")";
            db.execSQL(CREATE_CONTACTS_TABLE);
            }
        }

public void addContact(Contact contact) {
        SQLiteDatabase db = this.getWritableDatabase();

        ContentValues values = new ContentValues();
        values.put(ACTIVITY_NAME, contact._name); // Contact Name
        values.put(ACTIVITY_DESCRIPTION, contact._description);
        values.put(ACTIVITY_STARTTIME, contact._startTime);
        values.put(DURATION, contact._duration);
        values.put(ACTIVITY_STARTDATE, contact._startDate);
        values.put(ACTIVITY_ENDDATE, contact._endDate);
        values.put(ACTIVITY_DAY, contact._day);
        values.put(ACTIVITY_STATUS, contact._status);
        // Inserting Row
        db.insert(TABLE_CONTACTS, null, values);
        db.close(); // Closing database connection
    }
public List<Contact> getAllContacts() {
        List<Contact> contactList = new ArrayList<Contact>();
        // Select All Query
        String selectQuery = "SELECT  * FROM activity ORDER BY acticity_name";

        SQLiteDatabase db = this.getWritableDatabase();
        Cursor cursor = db.rawQuery(selectQuery, null);
        // looping through all rows and adding to list
        if (cursor.moveToFirst()) {
            do {
                Contact contact = new Contact();
                contact.setID(Integer.parseInt(cursor.getString(0)));
                contact.setName(cursor.getString(cursor.getColumnIndex(ACTIVITY_NAME)));
                contact.setDescription(cursor.getString(cursor.getColumnIndex(ACTIVITY_DESCRIPTION)));
                contact.setStartTime(cursor.getString(cursor.getColumnIndex(ACTIVITY_STARTTIME)));
                contact.setDuration(cursor.getString(cursor.getColumnIndex(DURATION)));
                contact.setStartDate(cursor.getString(cursor.getColumnIndex(ACTIVITY_STARTDATE)));
                contact.setEndDate(cursor.getString(cursor.getColumnIndex(ACTIVITY_ENDDATE)));
                contact.setDay(cursor.getString(cursor.getColumnIndex(ACTIVITY_DAY)));
                contact.setStatus(cursor.getString(cursor.getColumnIndex(ACTIVITY_STATUS)));

                // Adding contact to list
                contactList.add(contact);
            } while (cursor.moveToNext());
        }
        // close inserting data from database
        db.close();
        // return contact list
        return contactList;

    }

Contact.class

package com.om.database.categories;

public class Contact {
    // private variables
    int _id;
    String _name;
    String _description;
    String _startTime;
    String _duration;
    String _startDate;
    String _endDate;
    String _day;
    String _status;

    // Empty constructor
    public Contact() {
    }

    // constructor
    public Contact(String name, String description, String startTime,
            String duration, String startDate, String endDate, String day,
            String status) {
        this._name = name;
        this._description = description;
        this._startTime = startTime;
        this._duration = duration;
        this._startDate = startDate;
        this._endDate = endDate;
        this._day = day;
        this._status = status;

    }



    public Contact(int keyId) {
        this._id = keyId;
    }

    // getting ID
    public int getID() {
        return this._id;
    }

    // setting id
    public void setID(int keyId) {
        this._id = keyId;
    }

    // getting name
    public String getName() {
        return this._name;
    }

    // setting name
    public void setName(String name) {
        this._name = name;
    }
    // getting Description
        public String getDescription() {
            return this._description;
        }

        // setting Description
        public void setDescription(String description) {
            this._description = description;
        }

    // getting startTiem
    public String getStartTime() {
        return this._startTime;
    }

    // setting StartTime
    public void setStartTime(String startTime) {
        this._startTime = startTime;
    }

    // getting Duration
    public String getDuration() {
        return this._duration;
    }

    // setting Duration
    public void setDuration(String duratrion) {
        this._duration = duratrion;
    }

    // getting startDate
    public String getStartDate() {
        return this._startDate;
    }

    // setting startDate
    public void setStartDate(String StartDate) {
        this._startDate = StartDate;
    }

    // getting endDate
    public String getEndDate() {
        return this._endDate;
    }

    // setting Duration
    public void setEndDate(String endDate) {
        this._endDate = endDate;
    }

    // getting Day
    public String getDay() {
        return this._day;
    }

    // setting day
    public void setDay(String day) {
        this._duration = day;
    }

    // getting Status
    public String getStatus() {
        return this._status;
    }

    // setting status
    public void setStatus(String status) {
        this._status = status;
    }
}

my Problem is in the duration column am getting NULL value instead of time intervals. if you need more information let me know will update the post.