android: saving json to sqlite

Question

i'm a new bie in android and java i want to save a table from sql server(external database) to sqlite(internal database). 1. my json is not getting stored and every record is same like this "com.example.db_client.DeptTable@b3e4e9e0" when i opens the db file in sqlite browser. I don't understand what is this.

2. when i run my app i sometimes get this exception and sometimes i don't.

   FATAL EXCEPTION: main Process: com.example.db_client, PID: 1697 java.lang.IllegalArgumentException: Activity DeptActivity does not have a parent activity name specified. (Did you forget to add the android.support.PARENT_ACTIVITY element in your manifest?)

I really need help please look into my problem. thanks in advance.

code of database helper class

    public class SqliteDB {

    public static final String KEY_ID = "no";
    public static final String KEY_NAME = "name";

    private static final String TAG = "DBAdapter";
    private static final String DATABASE_NAME = "SQLiteDB";

    private static final String TABLE_NAME = "Department";
    private static final int DATABASE_VERSION = 2;

    private static final String CREATE_TABLE = 
            "create table departmentList (id INTEGER PRIMARY KEY, name TEXT);";
    private final Context context;
    private DatabaseHelper DBHelper;
    private SQLiteDatabase db;

    public SqliteDB(Context ctx) {

        this.context = ctx;
        DBHelper = new DatabaseHelper(context);
    }
    private static class DatabaseHelper extends SQLiteOpenHelper {
        DatabaseHelper(Context context) {           
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
    }

    @Override
        public void onCreate(SQLiteDatabase db) {           
            try {
                    db.execSQL(CREATE_TABLE);
                } catch (SQLException e) {
                    e.printStackTrace();
                }
        }

        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {   
            Log.w(TAG, "Upgrading database from version " + oldVersion + " to "
                    + newVersion + ", which will destroy all old data");
            db.execSQL("DROP TABLE IF EXISTS sample");
            onCreate(db);
            }
        }

  //---open SQLite DB---
    public SqliteDB open() throws SQLException {    
        db = DBHelper.getWritableDatabase();
        return this;
    }

    //---close SQLite DB---
    public void close() {   
        DBHelper.close();
    }

    //---insert data into SQLite DB---
    public long insert(String name) {
        ContentValues initialValues = new ContentValues();
        initialValues.put(KEY_NAME, name);      
        return db.insert(TABLE_NAME, null, initialValues);
    }

    //---Delete All Data from table in SQLite DB---
    public void deleteAll() {
        db.delete(TABLE_NAME, null, null);
    }

    //---Get All Contacts from table in SQLite DB---
    public Cursor getAllData() {
        return db.query(TABLE_NAME, new String[] {KEY_NAME}, 
                null, null, null, null, null);
    }

}

code of activity class

public class DeptActivity extends Activity{


    ArrayAdapter<String> adapter;
    ListView listv;
    Context context;
    ArrayList<String> data;
    SqliteDB sqlite;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_dept);

          sqlite = new SqliteDB(DeptActivity.this);

          setupActionBar();
          data = new ArrayList<String>();
          listv = (ListView) findViewById(R.id.lv_dept);
          context = this;

          adapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1, data);
          listv.setAdapter(adapter);
          Toast.makeText(this,"Loading Please Wait..",Toast.LENGTH_SHORT).show();
          new AsyncLoadDeptDetails().execute();
    }
    public class AsyncLoadDeptDetails extends
          AsyncTask<Void, JSONObject, ArrayList<DeptTable>> {
          ArrayList<DeptTable> deptTable = null;

          @Override
          public ArrayList<DeptTable> doInBackground(Void... params) {
                // TODO Auto-generated method stub

                RestAPI api = new RestAPI();
                try {
                       JSONObject jsonObj = api.GetDepartmentDetails();
                       JSONParser parser = new JSONParser();
                       Log.i( "department list", jsonObj.toString()); 
                       deptTable = parser.parseDepartment(jsonObj);
                       sqlite();

                } catch (Exception e) {
                }
          return deptTable;
      }


         private void sqlite() {
            // TODO Auto-generated method stub

            sqlite.open();
        for(int i=0; i<deptTable.size(); i++) {

                sqlite.insert(deptTable.get(i).toString());

            }

            sqlite.close();
        }   

          @Override
          protected void onPostExecute(ArrayList<DeptTable> result) {
                // TODO Auto-generated method stub

                for (int i = 0; i < result.size(); i++) {
                      data.add(result.get(i).getNo() + " " + result.get(i).getName());
                }

                adapter.notifyDataSetChanged();

                Toast.makeText(context,"Loading Completed",Toast.LENGTH_SHORT).show();
          } }

and the table which i want to save in sqlite db looks like this. no. name 1 engineering 2 finance 3 commerce

public class DeptTable {

 int no;
 String name;

 public DeptTable(int no, String name) {
       super();
       this.no = no;
       this.name = name;
 }

code of deptTable Class

public DeptTable() {
       super();
       this.no=0;
       this.name = null;
 }

 public int getNo() {
       return no;
 }
 public void setNo(int no) {
       this.no = no;
 }
 public String getName() {
       return name;
 }
 public void setName(String name) {
       this.name = name;
 }

} code of json parser class

public class JSONParser  {

public JSONParser()
{
super();
}

public ArrayList<DeptTable> parseDepartment(JSONObject object)
{
      ArrayList<DeptTable> arrayList=new ArrayList<DeptTable>();
      try {
            JSONArray jsonArray=object.getJSONArray("Value");
            JSONObject jsonObj=null;
            for(int i=0;i<jsonArray.length();i++)
            {
                  jsonObj =jsonArray.getJSONObject(i);
                  arrayList.add(new DeptTable(jsonObj.getInt("no"), jsonObj.getString("name")));
            }

      } catch (JSONException e) {
            // TODO Auto-generated catch block
            Log.d("JSONParser => parseDepartment", e.getMessage());
      }
      return arrayList;
}

public boolean parseUserAuth(JSONObject object)
{     boolean userAtuh=false;
            try {
                  userAtuh = object.getBoolean("Value");
            } catch (JSONException e) {
                  // TODO Auto-generated catch block
                  Log.d("JSONParser => parseUserAuth", e.getMessage());
            }

            return userAtuh; }

code of manifest

<uses-sdk
    android:minSdkVersion="8"
    android:targetSdkVersion="21" />

<uses-permission android:name="android.permission.INTERNET" />

<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <activity
        android:name=".MainActivity"
        android:label="@string/app_name" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <activity
        android:name="com.example.db_client.DeptActivity"
        android:label="@string/app_name" >
     </activity>

</application>
</manifest>

enter code here

Answer 1

If you want to use the toString method the class has to implement the toString method otherwise it will just return the default for object with you find out is not so useful. (This "com.example.db_client.DeptTable@b3e4e9e0"). To implement it just type do like this.

@Override
public String toString() {
    //What you want to return here.
}

But I'm guessing you want to add some value to the database so you want to call the getter method of your class like this.

private void sqlite() {
    sqlite.open();
    for(int i=0; i<deptTable.size(); i++) {
        sqlite.insert(deptTable.get(i).getName());
    }
    sqlite.close();
}

You need to add the android:parentActivityName field to DeptActivity like this.

<uses-sdk
    android:minSdkVersion="8"
    android:targetSdkVersion="21" />

<uses-permission android:name="android.permission.INTERNET" />

<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <activity
        android:name=".MainActivity"
        android:label="@string/app_name" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <activity
        android:name="com.example.db_client.DeptActivity"
        android:label="@string/app_name"
        android:parentActivityName=".MainActivity">
     </activity>

</application>
</manifest>