定義
抽象工廠模式提供一個(gè)創(chuàng)建一系列相關(guān)或相互依賴對(duì)象的接口，而無(wú)需指定它們具體的類
角色
- 抽象產(chǎn)品類A
- 抽象產(chǎn)品類B
- 抽象工廠類
- 具體工廠類C（生成A）
- 具體工廠類D（生產(chǎn)B）
UML類圖
抽象工廠模式UML類圖
代碼
- IBenz.java
public interface IBenz {
void run();
}
- IBWM.java
public interface IBWM {
void run();
}
- HomeUseBenz.java
public class HomeUseBenz implements IBenz {
@Override
public void run() {
System.out.println("first.HomeUseBenz run");
}
}
- HomeUseBWM.java
public class HomeUseBWM implements IBWM {
@Override
public void run() {
System.out.println("first.HomeUseBWM run");
}
}
- BusinessUseBenz.java
public class BusinessUseBenz implements IBenz {
@Override
public void run() {
System.out.println("first.BusinessUseBenz run");
}
}
- BusinessUseBWM.java
public class BusinessUseBWM implements IBWM {
@Override
public void run() {
System.out.println("first.BusinessUseBWM run");
}
}
- AbstarctFactory.java
public abstract class AbstarctFactory {
public abstract IBWM createBWM();
public abstract IBenz createBenz();
}
- HomeUseFactory.java
public class HomeUseFactory extends AbstarctFactory {
@Override
public IBWM createBWM() {
return new HomeUseBWM();
}
@Override
public IBenz createBenz() {
return new HomeUseBenz();
}
}
- BusinessFactory.java
public class BusinessFactory extends AbstarctFactory {
@Override
public IBWM createBWM() {
return new BusinessUseBWM();
}
@Override
public IBenz createBenz() {
return new BusinessUseBenz();
}
}
抽象工廠模式的優(yōu)點(diǎn)
- 1 易于交換產(chǎn)品系列膘怕，由于具體工廠類却特，在一個(gè)應(yīng)用中只需要在初始化的時(shí)候出現(xiàn)一次口柳，這就使得改變一個(gè)應(yīng)用的具體工廠變得非常容易竹勉，它只需要改變具體工廠即可使用不同的產(chǎn)品配置
- 2 它讓具體的創(chuàng)建實(shí)例的過程與客戶端分離剧包，客戶端是通過它們的抽象接口操作實(shí)例驳癌，產(chǎn)品的具體類名也被具體工廠的實(shí)現(xiàn)分離滑燃，不會(huì)出現(xiàn)在客戶代碼中
抽象工廠模式的缺點(diǎn)
如果想要增加一個(gè)不同的車型，則需要增加三個(gè)類以及修改三個(gè)工廠颓鲜，比較繁瑣表窘！
使用簡(jiǎn)單工廠改進(jìn)抽象工廠
UML類圖
簡(jiǎn)單工廠改進(jìn)抽象工廠UML.png
代碼
- AllFactory.java
public class AllFactory {
private static final String type = "home";
//private static final String type = "business";
public static IBenz createBenz(){
IBenz benz = null;
switch (type){
case "home":
benz = new HomeUseBenz();
break;
case "business":
benz = new BusinessUseBenz();
break;
}
return benz;
}
public static IBWM createBWM(){
IBWM bwm = null;
switch (type){
case "home":
bwm = new HomeUseBWM();
break;
case "business":
bwm = new BusinessUseBWM();
break;
}
return bwm;
}
}
使用反射改進(jìn)抽象工廠方法
public class AllFactory {
private final static String type="homeUse";
//private final static String type="businessUse";
public static IBenz createBenz() throws ClassNotFoundException, IllegalAccessException, InstantiationException {
String className = type.substring(0, 1).toUpperCase() + type.substring(1) + "Benz";
//獲取包路徑
String packageName = new Object() {
public String getPackageName() {
return this.getClass().getPackage().getName();
}
}.getPackageName();
Class<? extends IBenz> clazz = (Class<? extends IBenz>) Class.forName(packageName+"."+className);
return clazz.newInstance();
}
public static IBWM createBWM() throws IllegalAccessException, InstantiationException, ClassNotFoundException {
String className = type.substring(0, 1).toUpperCase() + type.substring(1) + "BWM";
//獲取包路徑
String packageName = new Object() {
public String getPackageName() {
return this.getClass().getPackage().getName();
}
}.getPackageName();
Class<? extends IBWM> clazz = (Class<? extends IBWM>) Class.forName(packageName +"."+className);
return clazz.newInstance();
}
}
