Android search in Listview

package com.crumbin.tabs;

//import android.app.TabActivity;
import java.util.ArrayList;
import android.app.Activity;
import android.os.Bundle;
import android.text.Editable;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.ListView;
import android.text.TextWatcher;
import com.crumbin.main.R;

public class ExploreActivity extends Activity{
    private ListView lv;
        private EditText et;
        private String listview_array[] = { "Amit","Ashish","Guruji","Pandey gopal","Anirudh Khusape","Siddharth Menon","Alaskar","Summy Kapoor","Pardus",
                                            "Amit Savartkar","Shushil","Eldhose","Gopal"};


        private ArrayList<String> array_sort= new ArrayList<String>();
        int textlength=0;

        public void onCreate(Bundle savedInstanceState){

            super.onCreate(savedInstanceState);
            setContentView(R.layout.explore_tab);


            lv = (ListView) findViewById(R.id.ListView01);
            et = (EditText) findViewById(R.id.EditText01);
            lv.setAdapter(new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1, listview_array));
            et.addTextChangedListener(new TextWatcher()

            {


                public void afterTextChanged(Editable s){
                    // Abstract Method of TextWatcher Interface.
                }

                public void beforeTextChanged(CharSequence s,int start, int count, int after){
                    // Abstract Method of TextWatcher Interface.
                }
                public void onTextChanged(CharSequence s,int start, int before, int count){
                    textlength = et.getText().length();
                    array_sort.clear();
                    for (int i = 0; i < listview_array.length; i++){
                        if (textlength <= listview_array[i].length()){
                            if(et.getText().toString().equalsIgnoreCase((String)listview_array[i].subSequence(0,textlength)))
                            {
                                array_sort.add(listview_array[i]);
                            }
                        }
                    }
                    lv.setAdapter(new ArrayAdapter<String>(ExploreActivity.this,android.R.layout.simple_list_item_1, array_sort));
                }
            });
        }
}

/*

XML > explore_tab.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout android:id="@+id/LinearLayout01"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:orientation="vertical">

    <EditText android:id="@+id/EditText01"
    android:layout_height="wrap_content"
    android:layout_width="fill_parent"
    android:hint="Search">
    </EditText>

    <ListView android:id="@+id/ListView01"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" >
    </ListView>
</LinearLayout>

*/