Android检查多个字符串是否为空

更清洁的方法是

public static boolean isAnyStringNullOrEmpty(String... strings) {
    for (String s : strings)
        if (s == null || s.isEmpty())
            return true;
    return false;
}

然后你就可以这样称呼它

if (isAnyStringNullOrEmpty(firstname, lastname, amount, timespan, iban)) {
    Toast.makeText(MainActivity.this, "Oops, you forgot to fill in some fields!", Toast.LENGTH_SHORT).show();
} else {

}