工厂模式和抽象工厂模式

工厂模式: 定义一个用于创建对象的接口,让他的子类决定实例化哪个类.使类的实例化延迟到子类.

1.普通的工厂模式:

public class GoodProduct implements Product {
private String prodInfo = "Iam the good prod";
public String getProductInfo() {
// TODO Auto-generated method stub
return this.prodInfo;
}

public void setProdInfo(String prodInfo) {
// TODO Auto-generated method stub
this.prodInfo = prodInfo;
}
}

public class BadProduct implements Product {

public String getProductInfo() {
// TODO Auto-generated method stub
return "Iam the bad product";
}
public void setProdInfo(String prodInfo) {
// TODO Auto-generated method stub

}
}

public class ProdCreator implements Creator {

public <t extends Product> t getProd(Class<t> c) {
// TODO Auto-generated method stub
t ret = null;
try {
ret = (t) Class.forName(c.getName()).newInstance();
} catch (InstantiationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
return ret;
}
}
}

2。多个工厂的工厂模式:

public class BadProdCreator {
public Product getProd(){
return new BadProduct();
}
}

goodProdCreator 同理。

调用方法：

public static void main(String[] args) {
// TODO Auto-generated method stub
ProdCreator pc = new ProdCreator();
GoodProduct gp = pc.getProd(GoodProduct.class);
System.out.println(gp.getProductInfo());
BadProduct bp = pc.getProd(BadProduct.class);
System.out.println(bp.getProductInfo());
gp = SimpleCreator.getProd(GoodProduct.class);
bp = SimpleCreator.getProd(BadProduct.class);
System.out.println(gp.getProductInfo());
System.out.println(bp.getProductInfo());
BadProdCreator bpc = new BadProdCreator();
System.out.println(bpc.getProd().getProductInfo());
}

抽象工厂模式：为创建一组相关或者相互依赖的对象提供接口，无需指定具体的类。

public class GoodLargeProd extends AbstractGoodProd{

public String getProductInfo() {
// TODO Auto-generated method stub
return "I am good large Prod";
}

public void setProdInfo(String prodInfo) {
// TODO Auto-generated method stub
}

}

public abstract class abstractCreator {
　　public abstract Product getLargeProduct();
　　public abstract Product getSmallProduct();
}

public class GoodProdCreator extends abstractCreator {

@Override
public Product getLargeProduct() {
// TODO Auto-generated method stub
return new GoodLargeProd();
}

@Override
public Product getSmallProduct() {
// TODO Auto-generated method stub
return new GoodSmallProd();
}
}

说明的一点是: 抽象工厂模式(以上面的例子来说)扩充产品的small,large等需要改abstractcreator 的接口，但加个badprod等就比较方便。

用工厂模式的creator 也可以创建对象。

public class GoodProdNormalCreator implements Creator {

public <t extends Product> t getProd(Class<t> c) {
// TODO Auto-generated method stub
t ret = null;
try {
ret = (t)Class.forName(c.getName()).newInstance();
} catch (InstantiationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
return ret;
}
}

}

 这样可以创建任何的prod的之类（报错多级子类）。