接口、lambda表达式与内部类

    1.比较器

    1. import java.util.Comparator;
    3. /**
    4.  * @author zhuangshd
    5.  * @date 2021/9/7 23:06
    6.  */
    7. public class LengthComparator implements Comparator<String> {
    9.     @Override
    10.     public int compare(String first, String second) {
    11.         return first.length() - second.length();
    12.     }
    13. }
    15. import java.util.Arrays;
    17. /**
    18.  * @author zhuangshd
    19.  * @date 2021/9/7 23:07
    20.  */
    21. public class Test {
    23.     public static void main(String[] args) {
    24.         String[] friends = {"apple", "mary", "coco"};
    25.         Arrays.sort(friends, new LengthComparator());
    26.         System.out.println(friends[1]);
    27.         LengthComparator lengthComparator = new LengthComparator();
    28.         int compare = lengthComparator.compare(friends[0], friends[1]);
    29.         System.out.println(compare);
    31.     }
    32. }

    2.接口的默认方法

    1. /**
    2.  * @author zhuangshd
    3.  * @date 2021/9/7 23:17
    4.  */
    5. public interface DefaultComparator {
    7.     default String getName() {
    8.         return "zhuangshd";
    9.     }
    10. }
    12. /**
    13.  * @author zhuangshd
    14.  * @date 2021/9/7 23:19
    15.  */
    16. public interface DefaultInterface {
    18.     default String getName() {
    19.         return "zsd";
    20.     }
    21. }
    23. /**
    24.  * 接口默认方法冲突
    25.  *
    26.  * @author zhuangshd
    27.  * @date 2021/9/7 23:20
    28.  */
    29. public class GetNameTest implements DefaultComparator, DefaultInterface {
    31.     @Override
    32.     public String getName() {
    33.         return "coco";
    34.     }
    35. }

    3.类单继承多实现接口，定义静态类的扩展性限制在于单继承；回调是一种设计模式；
    4.对象克隆

    1. /**
    2.  * 克隆，默认浅拷贝
    3.  *
    4.  * @author zhuangshd
    5.  * @date 2021/9/7 23:20
    6.  */
    7. public class GetNameTest implements Cloneable {
    9.     @Override
    10.     protected Object clone() throws CloneNotSupportedException {
    11.         return super.clone();
    12.     }
    13. }

    4.Lambda表达式