getting error while using ViewHolder in a sqlite based application

1public class DataHelper extends SQLiteOpenHelper {
2 public static String DATABASE="kuldb";
3 public static String DB_TABLE="friends";
4 public static String COL_id="id";
5 public static String COL_NAME="name";
6 public static String COL_ADD="address";
7 public static String COL_PH="call";
8
9 ArrayList<FriendModel>cartlist=new ArrayList<FriendModel>();
10 Context c;
11 public DataHelper(Context c){
12 super(c,DATABASE,null,1);
13 }
14 public void onCreate(SQLiteDatabase db){
15 db.execSQL("create table friends(id integer primary key autoincrement,name text,address text,call text)");
16 }
17 public void onUpgrade(SQLiteDatabase db,int oldv,int newv){
18 db.execSQL("drop table if exist "+DB_TABLE);
19 this.onCreate(db);
20 }
21
22 public void putfriends(FriendModel fritype){
23 SQLiteDatabase sd=this.getWritableDatabase();
24 ContentValues cv=new ContentValues();
25 cv.put("name", fritype.friname);
26 cv.put("address", fritype.friadd);
27 cv.put("call", fritype.friph);
28 sd.insert("friends", null, cv);
29 sd.close();
30 }
31
32 public void updatefri(FriendModel frilist){
33 SQLiteDatabase sd=this.getWritableDatabase();
34 ContentValues cv=new ContentValues();
35 cv.put("name", frilist.friname);
36 cv.put("address", frilist.friadd);
37 cv.put("call", frilist.friph);
38 sd.update("friends", cv, "name="+ frilist.friname, null);
39 sd.close();
40 }
41 public void emptyfriends(){
42 try{
43 SQLiteDatabase sd=this.getWritableDatabase();
44 sd.execSQL("delete from friends");
45 sd.close();
46 }catch(Exception e){
47 e.printStackTrace();
48 }
49 }
50 public void removefriend(String fname,String fadd,String fph){
51 try{
52 SQLiteDatabase sd=this.getWritableDatabase();
53 String[]arg={fname};
54 sd.delete("friends", "name=?", arg);
55 sd.close();
56 }catch(Exception e){
57 e.printStackTrace();
58 }
59 }
60
61 public ArrayList<FriendModel>getallfriends(){
62 cartlist.clear();
63 SQLiteDatabase sd=this.getWritableDatabase();
64 Cursor c=sd.rawQuery("select * from friends", null);
65 if(c.getCount()!=0){
66 if(c.moveToFirst()){
67 do{
68 FriendModel type=new FriendModel();
69 type.friname=c.getString(c.getColumnIndex("name"));
70 type.friadd=c.getString(c.getColumnIndex("address"));
71 type.friph=c.getString(c.getColumnIndex("call"));
72 cartlist.add(type);
73 }while(c.moveToNext());
74 }
75 }
76 c.close();
77 sd.close();
78 return cartlist;
79
80 }
81}

1public class MainActivity extends Activity{
2 EditText fname,fadd,fcall;
3 Button fsave,fview;
4 FriendModel fm;
5 DataHelper help;
6 public void onCreate(Bundle b){
7 super.onCreate(b);
8 setContentView(R.layout.main);
9 fname=(EditText)findViewById(R.id.addname);
10 fadd=(EditText)findViewById(R.id.addcity);
11 fcall=(EditText)findViewById(R.id.addph);
12 fsave=(Button)findViewById(R.id.savedata);
13 fview=(Button)findViewById(R.id.viewdata);
14
15 fsave.setOnClickListener(new OnClickListener() {
16
17 @Override
18 public void onClick(View v) {
19 // TODO Auto-generated method stub
20 if(fname.getText().toString().equals("")
21 ||fadd.getText().toString().equals("")||fcall.getText().toString().equals("")){
22 Toast.makeText(MainActivity.this, "please Fill All data fields", Toast.LENGTH_LONG).show();
23 }
24 else{
25 help=new DataHelper(getApplicationContext());
26 help.getWritableDatabase();
27 fm=new FriendModel();
28 fm.friname=fname.getText().toString();
29 fm.friadd=fadd.getText().toString();
30 fm.friph=fcall.getText().toString();
31 help.putfriends(fm);
32 Toast.makeText(MainActivity.this, "Records Added sucessfully", Toast.LENGTH_LONG).show();
33 fname.setText("");
34 fadd.setText("");
35 fcall.setText("");
36 }
37
38
39 }
40 });
41
42 fview.setOnClickListener(new OnClickListener() {
43
44 @Override
45 public void onClick(View v) {
46 // TODO Auto-generated method stub
47 Intent i=new Intent(getApplicationContext(),ViewFriends.class);
48 startActivity(i);
49 }
50 });
51 }
52
53}

1public class FriendModel {
2 public String friname="";
3 public String friadd="";
4 public String friph="";
5
6 public String getfriname(){
7 return friname;
8 }
9 public void setfriname(String friname){
10 this.friname=friname;
11 }
12 public String getfriadd(){
13 return friadd;
14 }
15 public void setfriadd(String friadd){
16 this.friadd=friadd;
17 }
18 public String getfriph(){
19 return friph;
20 }
21 public void setfriph(String friph){
22 this.friph=friph;
23 }
24
25}

1public class ViewFriends extends Activity{
2 TextView totalfans;
3 ListView listview;
4 DataHelper help;
5 ArrayList<FriendModel>friendlist=new ArrayList<FriendModel>();
6
7 public void onCreate(Bundle b){
8 super.onCreate(b);
9 setContentView(R.layout.view_record);
10 totalfans=(TextView)findViewById(R.id.totalrecords);
11 listview=(ListView)findViewById(R.id.listview);
12 }
13 public void onResume(){
14 super.onResume();
15 friendlist.clear();
16 help=new DataHelper(getApplicationContext());
17 help.getWritableDatabase();
18 ArrayList<FriendModel>fanlist=help.getallfriends();
19 for(int i=0;i<fanlist.size();i++){
20 String tfname=fanlist.get(i).getfriname();
21 String tfadd=fanlist.get(i).getfriadd();
22 String tfph=fanlist.get(i).getfriph();
23
24 FriendModel fan=new FriendModel();
25 fan.setfriname(tfname);
26 fan.setfriadd(tfadd);
27 fan.setfriph(tfph);
28 friendlist.add(fan);
29 }
30 totalfans.setText("Total Records Found: "+friendlist.size());
31 listview.setAdapter(new ListAdapter(this));
32 help.close();
33
34 }
35 private class ListAdapter extends BaseAdapter{
36 LayoutInflater inflater;
37 ViewHolder viewholder;
38
39 public ListAdapter(Context c){
40 inflater=LayoutInflater.from(c);
41 }
42
43 @Override
44 public int getCount() {
45 // TODO Auto-generated method stub
46 return friendlist.size();
47 }
48
49 @Override
50 public Object getItem(int position) {
51 // TODO Auto-generated method stub
52 return position;
53 }
54
55 @Override
56 public long getItemId(int position) {
57 // TODO Auto-generated method stub
58 return position;
59 }
60
61 @Override
62 public View getView(int position, View convertView, ViewGroup parent) {
63 // TODO Auto-generated method stub
64 if(convertView==null){
65 convertView=inflater.inflate(R.layout.item_record, null);
66 ViewHolder viewholder=new ViewHolder();
67 viewholder.tfriname=(TextView)convertView.findViewById(R.id.namedb);
68 viewholder.tfriadd=(TextView)convertView.findViewById(R.id.addressdb);
69 viewholder.tfriph=(TextView)convertView.findViewById(R.id.calldb);
70 convertView.setTag(viewholder);
71 }
72 else{
73 viewholder=(ViewHolder)convertView.getTag();
74 }
75 viewholder.tfriname.setText(friendlist.get(position).getfriname());
76 viewholder.tfriadd.setText(friendlist.get(position).getfriadd().trim());
77 viewholder.tfriph.setText(friendlist.get(position).getfriph().trim());
78 final int temp=position;
79
80 (convertView.findViewById(R.id.update)).setOnClickListener(new OnClickListener() {
81
82 @Override
83 public void onClick(View v) {
84 // TODO Auto-generated method stub
85 String updatename=friendlist.get(temp).getfriname();
86 String updateadd=friendlist.get(temp).getfriadd();
87 String updateph=friendlist.get(temp).getfriph();
88 Intent in=new Intent(ViewFriends.this,Update.class);
89 in.putExtra("fname", updatename);
90 in.putExtra("fadd", updateadd);
91 in.putExtra("fph", updateph);
92 startActivity(in);
93
94 }
95 });
96 (convertView.findViewById(R.id.delete)).setOnClickListener(new OnClickListener() {
97
98 @Override
99 public void onClick(View v) {
100 // TODO Auto-generated method stub
101 AlertDialog.Builder adb=new AlertDialog.Builder(ViewFriends.this);
102 adb.setCancelable(true);
103 adb.setMessage("Are you Sure about Delete Record???");
104 adb.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
105
106 @Override
107 public void onClick(DialogInterface dialog, int which) {
108 // TODO Auto-generated method stub
109 help.removefriend(friendlist.get(temp).getfriname().trim()
110 , friendlist.get(temp).getfriadd().trim(),friendlist.get(temp).getfriph().trim());
111 ViewFriends.this.onResume();
112 Toast.makeText(ViewFriends.this, "Record Deleted Sucessfully", Toast.LENGTH_LONG).show();
113
114 }
115 });
116 adb.setNegativeButton("No", new DialogInterface.OnClickListener() {
117
118 @Override
119 public void onClick(DialogInterface dialog, int which) {
120 // TODO Auto-generated method stub
121
122 }
123 });
124 adb.show();
125
126 }
127 });
128 return convertView;
129 }
130
131 }
132 private class ViewHolder{
133 TextView tfriname;
134 TextView tfriadd;
135 TextView tfriph;
136 }
137
138}