public class MainActivity extends AppCompatActivity {
Button button;
TextView textView;
String TAG = MainActivity.class.getName();//LOG TAG
ArrayList<String> contactName = new ArrayList<String>();
ArrayList<String> contactID=new ArrayList<String>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
button = (Button) findViewById(R.id.button);
textView = (TextView) findViewById(R.id.textView);
button.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
final Cursor kontakteList =
getContentResolver().query(//ContentResolver
ContactsContract.Contacts.CONTENT_URI,//URI
new String[]{//Select
ContactsContract.PhoneLookup._ID,
ContactsContract.PhoneLookup.DISPLAY_NAME},
null,//WHERE
null,//WHERE ARGS
null//ORDER
);//query
if(kontakteList.moveToFirst()) {//if Cursor not null
String[] columnNames = kontakteList.getColumnNames();//getColumnNames
Log.d(TAG, "column Names size: "+columnNames.length);
StringBuilder stringBuilder=new StringBuilder();
for (int i=0;i<columnNames.length;i++) {//Print Column Names
Log.d(TAG, columnNames[i].toString() + " i= " + i);
stringBuilder.append(columnNames[i].toString() + " ");
Log.d(TAG, stringBuilder.toString() + " sb i= " + i);
}//columnNames
stringBuilder.append(System.getProperty("line.separator"));
kontakteList.moveToFirst();
while(kontakteList.isAfterLast()==false) {//for each row, until after last row is reached
for (int i = 0; i < columnNames.length; i++) {//for each column
Log.d(TAG, " i: " + i + " " +kontakteList.getString(kontakteList.getColumnIndex(columnNames[i])));
stringBuilder.append(kontakteList.getString(kontakteList.getColumnIndex(columnNames[i])));
}//for
contactID.add(kontakteList.getString(kontakteList.getColumnIndex(columnNames[0])));
contactName.add(kontakteList.getString(kontakteList.getColumnIndex(columnNames[1])));
stringBuilder.append(System.getProperty("line.separator"));//generate a new line
kontakteList.moveToNext();//move to next row
}//while
Log.d(TAG, stringBuilder.toString());
textView.setText(stringBuilder.toString());//Display Data to Text View
}//if
}//onClick Method
});//setOnClickListener
}//onCreate
}//MainActivity
