글자비교를 어떻게 해야할지 몰라 너무 막막해하고있습니다. 도와주세요 ㅜㅜ

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

<AutoCompleteTextView android:id="@+id/find"
android:layout_width="fill_parent"
android:layout_height="wrap_content"/>

<Button android:id="@+id/btn_find"
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:text="버튼"></Button>


<ListView
android:id="@+id/list"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
/>



</LinearLayout>

일단 찾기 버튼을 누르면 Toast에 뜨게 해놨는데요~~ 어떻게 검색해야할까요 ㅜㅜ 도와주세요 ㅜㅜ

array.xml 에 cuontry두어 호출해서 그안에 리스트뷰 요소들을 넣어둿어요~~

public class Friend extends Activity {
public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);
setContentView(R.layout.main);
EditText find=(EditText)findViewById(R.id.find);

AutoCompleteTextView textView = (AutoCompleteTextView) findViewById(R.id.find);
String[] arCountry=getResources().getStringArray(R.array.country);
ArrayAdapter adapter = new ArrayAdapter(this,
android.R.layout.simple_dropdown_item_1line, arCountry);
textView.setAdapter(adapter);

Button btn= (Button)findViewById(R.id.btn_find);
btn.setOnClickListener(new Button.OnClickListener() {
public void onClick(View v) {
EditText edit = (EditText)findViewById(R.id.find);
String str = edit.getText().toString();
Toast.makeText(Friend.this, str, Toast.LENGTH_SHORT).show();

}
});

ListView list=(ListView)findViewById(R.id.list);
list.setAdapter(new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,arCountry));
list.setTextFilterEnabled(true);