泛型类继承时会产生类型擦除现象，导致多态失败。为了解决类型擦除与多态的冲突，Java编译器通过生成桥方法来解决这个问题。
package net.hw.poly; import java.time.LocalDate; /** * Created by howard on 2018/1/30. */ public class PolyDemo01 { public static void main(String[] args) { Pair<LocalDate> pair = new DateInterval(); pair.setFirst(LocalDate.of(2018, 1, 30)); pair.setSecond(LocalDate.of(2020, 12, 31)); } } class Pair<LocalDate> { private LocalDate first; private LocalDate second; public LocalDate getFirst() { return first; } public void setFirst(LocalDate first) { this.first = first; System.out.println("父类：setFirst"); } public LocalDate getSecond() { return second; } public void setSecond(LocalDate second) { this.second = se