从一个栗子开始，现在两种产品一个是普通轮胎，一个是越野轮胎，然后生产这两种产品，用工厂模式去实现是
public interface ITire {
void tire();
}
public class NormalTire implements ITire{
@Override
public void tire() {
System.out.println("普通轮胎");
}
}
public class SUVTire implements ITire{
@Override
public void tire() {
System.out.println("越野轮胎");
}
}
public class FactoryTire {
public static <T extends ITire> T createTire(Class<T> clz){
ITire tire = null;
try {
tire = (ITire) Class.forName(clz.getName()).newInstance();
} catch (Exception e) {
e.printStackTrace();
}
return (T) tire;
}
}
但是现在需求变了，我不生产轮胎要生产汽车了，那么汽车包含的零件就多了，绝不仅仅限于轮胎，而且汽车的款式也多，这么一个复杂的生产关系，我们就要用到抽象工厂设计模式了. 在这个时候抽象的工厂是汽车生产工厂，注意它不像简单工厂模式那样，仅仅局限于一种特定的产品去生产，所以我们这里还需要对工厂抽象。
先来看一张抽象工厂的uml.
image.png
目前需求是生产Q7和Q3汽车，那么需要引擎和轮胎两种零件，uml可以看成是
image.png
实际代码
public interface ITire {
void tire();
}
public class NormalTire implements ITire{
@Override
public void tire() {
System.out.println("普通轮胎");
}
}
public class SUVTire implements ITire{
@Override
public void tire() {
System.out.println("越野轮胎");
}
}
public interface IEngine {
void engine();
}
public class ImportEngine implements IEngine{
@Override
public void engine() {
System.out.println("进口发动机");
}
}
public class DemesticEngine implements IEngine{
@Override
public void engine() {
System.out.println("国产发动机");
}
}
public interface CarFactory {
ITire createTire();
IEngine createEngine();
}
public class Q3Factory implements CarFactory{
@Override
public ITire createTire() {
return new NormalTire();
}
@Override
public IEngine createEngine() {
return new DemesticEngine();
}
}
public class Q7Factory implements CarFactory{
@Override
public ITire createTire() {
return new SUVTire();
}
@Override
public IEngine createEngine() {
return new ImportEngine();
}
}
最后调用
Q3Factory q3Factory = new Q3Factory();
q3Factory.createEngine().engine();
q3Factory.createTire().tire();
Q7Factory q7Factory = new Q7Factory();
q7Factory.createEngine().engine();
q7Factory.createTire().tire();
输出
01-07 22:14:38.730 9413-9413/? I/System.out: 国产发动机
01-07 22:14:38.731 9413-9413/? I/System.out: 普通轮胎
01-07 22:14:38.732 9413-9413/? I/System.out: 进口发动机
01-07 22:14:38.732 9413-9413/? I/System.out: 越野轮胎
