Lamda 表达式比较器

比较器 Comparator 接口

lamda 表达式定法 和 比较器类写法

public class StringComparator implements Comparator<String> {

    @Override
    public int compare(String s1, String s2) {
        s1 = StringUtils.isEmpty(s1) ? "0" : s1;
        s2 = StringUtils.isEmpty(s2) ? "0" : s2;
        return Integer.valueOf(s1) - Integer.valueOf(s2);
    }

    static Comparator<String> strComparator = (str1, str2) -> {
        str1 = StringUtils.isEmpty(str1) ? "0" : str1;
        str2 = StringUtils.isEmpty(str2) ? "0" : str2;
        return Integer.valueOf(str1) - Integer.valueOf(str2);
    };

    public static void main(String[] args) {
        List<String> strings = Arrays.asList(new String[]{"311", "22", "44"});
        strings.sort(strComparator);
        for (String string : strings) {
            System.out.println(string);
        }
    }
}