1. public static <T extends Comparable> T min(T[] a)...
    1. package chapter08;
    3. public class ArrayAlg {
    4.     public static <T> T getMiddle(T... a) {
    5.         return a[a.length/2];
    6.     }
    8.     public static <T extends Comparable> T min(T[] a) {
    9.         if (a == null || a.length == 0) return null;
    10.         T smallest = a[0];
    11.         for (int i = 1; i < a.length; i++) {
    12.             if (smallest.compareTo(a[i]) > 0) {
    13.                 smallest = a[i];
    14.             }
    15.         }
    16.         return smallest;
    17.     }
    19.     public static void main(String[] args) {
    20.         String a = ArrayAlg.<String>getMiddle("abc", "def");
    21.         System.out.println(a);
    22.     }
    23. }

    使用多个限定:

    1. T extends Comparable & Serializable