Java设计模式之工厂模式案例详解
时间：2022-09-23 10:10:16 | 栏目：JAVA代码 | 点击：次
分类
1.简单工厂模式
2.工厂方法模式
3.抽象工厂模式
案例
需求
根据蛋糕的不同口味，分别创建苹果味和香蕉味的蛋糕实例
方案一:简单工厂模式
定义蛋糕父类
/**
* 蛋糕
* @author:liyajie
* @createTime:2022/2/14 10:17
* @version:1.0
*/
public class Cake {
}
定义苹果味的蛋糕
/**
* 苹果蛋糕
* @author:liyajie
* @createTime:2022/2/14 10:17
* @version:1.0
*/
public class AppleCake extends Cake{
public AppleCake(){
System.out.println("创建了苹果蛋糕实例");
}
}
定义香蕉味的蛋糕
/**
* 香蕉蛋糕
* @author:liyajie
* @createTime:2022/2/14 10:17
* @version:1.0
*/
public class BananaCake extends Cake{
public BananaCake(){
System.out.println("创建了香蕉蛋糕实例");
}
}
定义蛋糕工厂类
/**
* 蛋糕工厂
* @author:liyajie
* @createTime:2022/2/14 10:16
* @version:1.0
*/
public class CakeFactory {
public Cake createCake(String type){
if("apple".equals(type)){
return new AppleCake();
}else if("banana".equals(type)){
return new BananaCake();
}else {
return null;
}
}
}
定义测试类
/**
* 测试类
* @author:liyajie
* @createTime:2022/2/14 10:25
* @version:1.0
*/
public class Test {
public static void main(String[] args) {
CakeFactory cakeFactory = new CakeFactory();
cakeFactory.createCake("apple");
cakeFactory.createCake("banana");
}
}
查看结果：
方案二:工厂方法模式
定义蛋糕父类
/**
* 蛋糕父类
* @author:liyajie
* @createTime:2022/2/14 10:44
* @version:1.0
*/
public abstract class Cake {
}
定义苹果蛋糕
/**
* 苹果蛋糕
* @author:liyajie
* @createTime:2022/2/14 10:17
* @version:1.0
*/
public class AppleCake extends Cake {
public AppleCake(){
System.out.println("创建了苹果蛋糕实例");
}
}
定义香蕉蛋糕
/**
* 香蕉蛋糕
* @author:liyajie
* @createTime:2022/2/14 10:17
* @version:1.0
*/
public class BananaCake extends Cake {
public BananaCake(){
System.out.println("创建了香蕉蛋糕实例");
}
}
定义蛋糕工厂类 该类主要是定义了createCake抽象方法，并且在无参构造函数中进行调用，具体的实现是在子类里进行实例化的
/**
* 蛋糕工厂类
* @author:liyajie
* @createTime:2022/2/14 11:55
* @version:1.0
*/
public abstract class CakeFactory {
abstract Cake createCake();
public CakeFactory() {
createCake();
}
}
定义苹果蛋糕工具类
/**
* @desc:
* @author:liyajie
* @createTime:2022/2/14 11:58
* @version:1.0
*/
public class AppleCakeFactory extends CakeFactory{
@Override
public Cake createCake() {
return new AppleCake();
}
}
定义香蕉蛋糕工具类
/**
* @desc:
* @author:liyajie
* @createTime:2022/2/14 11:58
* @version:1.0
*/
public class BananaCakeFactory extends CakeFactory{
@Override
public Cake createCake() {
return new BananaCake();
}
}
定义测试类
/**
* 测试类
* @author:liyajie
* @createTime:2022/2/14 12:02
* @version:1.0
*/
public class Test {
public static void main(String[] args) {
AppleCakeFactory appleCakeFactory = new AppleCakeFactory();
BananaCakeFactory bananaCakeFactory = new BananaCakeFactory();
}
}
查看结果
方案三:抽象工厂模式
定义蛋糕父类
/**
* @desc:
* @author:liyajie
* @createTime:2022/2/14 10:44
* @version:1.0
*/
public abstract class Cake {
}
定义苹果蛋糕
/**
* 苹果蛋糕
* @author:liyajie
* @createTime:2022/2/14 10:17
* @version:1.0
*/
public class AppleCake extends Cake {
public AppleCake(){
System.out.println("创建了苹果蛋糕实例");
}
}
定义香蕉蛋糕
/**
* 香蕉蛋糕
* @author:liyajie
* @createTime:2022/2/14 10:17
* @version:1.0
*/
public class BananaCake extends Cake {
public BananaCake(){
System.out.println("创建了香蕉蛋糕实例");
}
}
定义蛋糕工厂类
/**
* @desc:
* @author:liyajie
* @createTime:2022/2/14 11:55
* @version:1.0
*/
public interface CakeFactory {
Cake createCake();
}
定义苹果蛋糕工厂类
/**
* @desc:
* @author:liyajie
* @createTime:2022/2/14 11:58
* @version:1.0
*/
public class AppleCakeFactory implements CakeFactory {
@Override
public Cake createCake() {
return new AppleCake();
}
}
定义香蕉蛋糕工厂类
/**
* @desc:
* @author:liyajie
* @createTime:2022/2/14 11:58
* @version:1.0
*/
public class BananaCakeFactory implements CakeFactory {
@Override
public Cake createCake() {
return new BananaCake();
}
}
定义蛋糕工厂生成器
/**
* @desc:
* @author:liyajie
* @createTime:2022/2/14 17:46
* @version:1.0
*/
public class FactoryProducter {
CakeFactory cakeFactory;
public FactoryProducter(CakeFactory cakeFactory){
setCakeFactory(cakeFactory);
}
public void setCakeFactory(CakeFactory cakeFactory){
this.cakeFactory = cakeFactory;
cakeFactory.createCake();
}
}
定义测试类
/**
* 测试类
* @author:liyajie
* @createTime:2022/2/14 12:02
* @version:1.0
*/
public class Test {
public static void main(String[] args) {
new FactoryProducter(new AppleCakeFactory());
new FactoryProducter(new BananaCakeFactory());
}
}
查看结果
对比分析
- 方案一：简单工厂模式，工厂类是只有一个，只需要改动这一个地方 避免了业务逻辑的代码和创建对象的代码大量耦合，降低耦合 让代码更加条理清晰，更加优雅
- 方案二：工厂方法模式是简单工厂模式的衍生，定义一个创建对象的抽象方法，由子类决定要实例化的类，将对象实例化延迟到子类，实现了可扩展，层次结构更复杂，可以应用到更复杂的场合
- 方案三：抽象工厂模式，定义一个接口来用于创建相关的或者具有依赖关系的对象簇，将实例化对象的细节提取出来，放到工厂角色，由工厂角色负责具体的创建细节，解耦合，提高项目可扩展性和可维护性
总结
通过以上三个案例，对比分析我们明确了三种工厂模式实现的方式，也对比分析了各个工厂模式的优点。但是切记，实际开发过程中，不要盲目的使用，一定要结合具体的业务，实际分析后才去使用。