package Demo_1_25_多例设计; public class Color { //描述颜色的类 private static final Color RED = new Color("红色"); private static final Color GREEN = new Color("绿色"); private static final Color BLUE = new Color("蓝色"); private String title; private Color(String title) { // 构造方法私有化 this.title = title; } public static Color getInstance(String color){ switch (color) { case "red": return RED; case "green": return GREEN; case "blue": return BLUE; default: return null; } } public String toString() { return this.title; } }
package Demo_1_25_多例设计; public class Main { public static void main(String[] args) { Color color = Color.getInstance("red"); System.out.println(color); } }