public class ToastUtil {
    private static Toast mToast = null;
    public static void showToast(Context context, String text, int duration) {
        if (mToast == null) {
            mToast = Toast.makeText(context, text, duration);
        } else {
            mToast.setText(text);
            mToast.setDuration(duration);
        }
        mToast.show();
    }
}

调用方法：

toastUtil.showToast(MainActivity.this, "tab1", Toast.LENGTH_SHORT);

ToastUtil工具类