Java源代码：抽象类和接口

public class GenericSort { public static void main(String[] args) { // Create an Integer array Integer[] intArray = { new Integer(2), new Integer(4), new Integer(3) }; // Create a Double array Double[] doubleArray = { new Double(3.4), new Double(1.3), new Double(-22.1) }; // Create a Character array Character[] charArray = { new Character('a'), new Character('J'), new Character('r') }; // Create a String array String[] stringArray = { "Tom", "John", "Fred" }; // Sort the arrays sort(intArray); sort(doubleArray); sort(charArray); sort(stringArray); // Display the sorted arrays System.out.print("Sorted Integer objects: "); printList(intArray); System.out.print("Sorted Double objects: "); printList(doubleArray); System.out.print("Sorted Character objects: "); printList(charArray); System.out.print("Sorted String objects: "); printList(stringArray); } /** Sort an array of comparable objects */ public static void sort(Object[] list) { Object currentMax; int currentMaxIndex; for (int i = list.length - 1; i >= 1; i--) { // Find the maximum in the list[0..i] currentMax = list[i]; currentMaxIndex = i; for (int j = i - 1; j >= 0; j--) { if (((Comparable) currentMax).compareTo(list[j]) < 0) { currentMax = list[j]; currentMaxIndex = j; } } // Swap list[i] with list[currentMaxIndex] if necessary; if (currentMaxIndex != i) { list[currentMaxIndex] = list[i]; list[i] = currentMax; } } } /** Print an array of objects */ public static void printList(Object[] list) { for (int i = 0; i < list.length; i++) System.out.print(list[i] + " "); System.out.println(); } }