How Can I Saved Onclickitem In Listview?

EditText txtInput;
Button btnAdd;
Button btnSave;
ListView list;

ArrayList<string> lists;
ArrayAdapter<string> aa;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    
    txtInput = (EditText)findViewById(R.id.txtInput);
    btnAdd = (Button)findViewById(R.id.btnAdd);
    btnSave = (Button)findViewById(R.id.btnSave);
    list = (ListView)findViewById(R.id.list);
    
    btnAdd.setOnClickListener(this);
    //txtInput.setOnKeyListener(this);
    
    lists = new ArrayList<string>();
    aa = new ArrayAdapter<string>(this, android.R.layout.simple_list_item_1, lists);
    list.setAdapter(aa);
    btnSave.setOnClickListener(new OnClickListener() {
		
		@Override
		public void onClick(View v) {
//still dont know what to do here
			list.getAdapter();
		}
	});
    
    list.setOnItemClickListener(new OnItemClickListener()
    {
		@Override
		public void onItemClick(AdapterView					int position, long id) {
				
			String text = parent.getItemAtPosition(position).toString();
			txtInput.setText(text);
		}
    	
	});
    list.setOnItemLongClickListener(new OnItemLongClickListener(){

		@Override
		public boolean onItemLongClick(AdapterView					int position, long id) {

			Toast.makeText(MainActivity.this, "Deleted!", Toast.LENGTH_SHORT).show();
			aa.remove((String) list.getAdapter().getItem(position));
			return true;
		}});
}
   
private void ADD(String item){
	if(item.length() > 0){
		this.lists.add(item);
		this.aa.notifyDataSetChanged();
		this.txtInput.setText("");
	}
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();
    if (id == R.id.action_settings) {
        return true;
    }
    return super.onOptionsItemSelected(item);
}


@Override
public void onClick(View v) {
	if(v == this.btnAdd){
		this.ADD(this.txtInput.getText().toString());
	}
}