一、什么是享元模式
Flyweight模式也叫享元模式,是构造型模式之一,它通过与其他类似对象共享数据来减小内存占用。
二、享元模式的结构
see the picture
三、享元模式的角色和职责
Flyweight模式也叫享元模式,是构造型模式之一,它通过与其他类似对象共享数据来减小内存占用。
二、享元模式的结构
see the picture

三、享元模式的角色和职责
抽象享元角色:
所有具体享元类的父类,规定一些需要实现的公共接口。具体享元角色:
抽象享元角色的具体实现类,并实现了抽象享元角色规定的方法。
享元工厂角色:负责创建和管理享元角色。
MyCharacter.java
public class MyCharacter {
private char mychar;
public MyCharacter(char mychar) {
this.mychar = mychar;
}
public void display() {
System.out.println(mychar);
}
}
MyCharacterFactory.java
import java.util.HashMap;
import java.util.Map;
public class MyCharacterFactory {
private Map<Character,MyCharacter> pool;
public MyCharacterFactory() {
pool = new HashMap<Character,MyCharacter>();
}
public MyCharacter getMyCharacter(Character character) {
MyCharacter myChar = pool.get(character);
if(myChar == null) {
myChar = new MyCharacter(character);
pool.put(character, myChar);
}
return myChar;
}
}
MainClass.java
public class MainClass {
public static void main(String[] args) {
// MyCharacter myChar1 = new MyCharacter('a');
// MyCharacter myChar2 = new MyCharacter('b');
// MyCharacter myChar3 = new MyCharacter('a');
// MyCharacter myChar4 = new MyCharacter('d');
//
// myChar1.display();
// myChar2.display();
// myChar3.display();
// myChar4.display();
//
// if(myChar1 == myChar3) {
// System.out.println("true");
// } else {
// System.out.println("false");
// }
//1.创建MyCharacter工厂
MyCharacterFactory factory = new MyCharacterFactory();
//2.从工厂中取出相应的MyCharacter
MyCharacter myChar1 = factory.getMyCharacter('a');
MyCharacter myChar2 = factory.getMyCharacter('b');
MyCharacter myChar3 = factory.getMyCharacter('a');
MyCharacter myChar4 = factory.getMyCharacter('d');
myChar1.display();
myChar2.display();
myChar3.display();
myChar4.display();
if(myChar1 == myChar3) {
System.out.println("true");
} else {
System.out.println("false");
}
}
}