标签：public ++ map new 方式 ack sys ash 类图
1.定义：提供了减少对象数量从而改善应用所需的对象结构的方式；
运用共享技术有效地支持大量细粒度的对象。
2.类型：结构型
3.适用场景：常常应用于底层的开发，以便解决系统的性能问题；
系统有大量相似对象、需要缓冲池的场景。
4.优点：减少对象的创建，降低内存中对象的数量，降低系统的内存，提高效率；
减少内存之外的其他资源占用。
5.缺点：关注内/外部状态、关注线程安全问题；使系统、程序的逻辑复杂化。
6.扩展：内部状态、外部状态
7.相关设计模式：代理模式、单例模式
8.实例目录package
9.实例UML类图
10.代码
1 package com.geely.design.pattern.structural.flyweight; 2 3 public interface Employee { 4 void report(); 5 }
1 package com.geely.design.pattern.structural.flyweight; 2 3 public class Manager implements Employee { 4 private String title = "部门经理"; 5 private String department; 6 private String reportContent; 7 8 public Manager(String department) { 9 this.department = department; 10 } 11 12 public void setReportContent(String reportContent) { 13 this.reportContent = reportContent; 14 } 15 16 @Override 17 public void report() { 18 System.out.println(reportContent); 19 } 20 }
1 package com.geely.design.pattern.structural.flyweight; 2 3 import java.util.HashMap; 4 import java.util.Map; 5 6 public class EmployeeFactory { 7 private static final Map<String,Employee> EMPLOYEE_MAP = new HashMap<>(); 8 9 public static Employee getManager(String department){ 10 Manager manager = (Manager) EMPLOYEE_MAP.get(department); 11 if(manager == null){ 12 manager = new Manager(department); 13 System.out.println("创建部门经理：" + department); 14 String reportContent = department + "部门汇报：此次报告的内容是。。。"; 15 manager.setReportContent(reportContent); 16 System.out.println("创建报告：" + reportContent); 17 EMPLOYEE_MAP.put(department,manager); 18 } 19 return manager; 20 } 21 }
1 package com.geely.design.pattern.structural.flyweight; 2 3 public class Test { 4 private static final String[] departments = {"RD", "QA", "PM", "BD"}; 5 public static void main(String[] args) { 6 for (int i = 0; i < 10; i++){ 7 String department = departments[(int)(Math.random()*departments.length)]; 8 Manager manager = (Manager) EmployeeFactory.getManager(department); 9 manager.report(); 10 } 11 12 Integer a = Integer.valueOf(100);//new Integer(100); 13 Integer b = 100; 14 Integer c = Integer.valueOf(1000);//new Integer(1000); 15 Integer d = 1000; 16 System.out.println("a==b:"+(a==b)); 17 System.out.println("c==d:"+(c==d)); 18 } 19 }
标签：public ++ map new 方式 ack sys ash 类图
原文地址：https://www.cnblogs.com/linbq1911/p/10229198.html
