02. Factory Method模式代码

2. Factory Method 本质：延迟到子类来选择实现
2.1 EXPORT OPERATE FACTORY
public interface ExportFileApi {
public boolean export(String data);
}
public class ExportDb implements ExportFileApi{
public boolean export(String data) {
System.out.println("Export data '" + data + "' to DB.");
return true;
}
}
public class ExportTxtFile implements ExportFileApi{
public boolean export(String data) {
System.out.println("Export data '" + data + "' to a TXT file.");
return true;
}
}
public abstract class ExportOperateFactory {
public boolean export(String data) {
ExportFileApi api = factoryMethod();
return api.export(data);
}
protected abstract ExportFileApi factoryMethod();
}
public class ExportDbOperateFactory extends ExportOperateFactory {
protected ExportFileApi factoryMethod() {
return new ExportDb();
}
}
public class ExportTxtFileOperateFactory extends ExportOperateFactory {
protected ExportFileApi factoryMethod() {
return new ExportTxtFile();
}
}
public class FactoryMethodClient {
public static void main(String[] args) {
ExportOperateFactory operateFactory = new ExportDbOperateFactory();
operateFactory.export("data for testing");
}
}
2.2 HUMAN FACTORY
public interface Human {
//每个人种都有相应的颜色
public void getColor();
//人类会说话
public void talk();
}
public class WhiteHuman implements Human {
//白色人种的颜色是白色的
public void getColor(){
System.out.println("白色人种的皮肤颜色是白色的！");
}
//白色人种讲话
public void talk() {
System.out.println("白色人种会说话，一般都是但是单字节。");
}
}
public class BlackHuman implements Human {
public void getColor(){
System.out.println("黑色人种的皮肤颜色是黑色的！");
}
public void talk() {
System.out.println("黑人会说话，一般人听不懂。");
}
}
public class YellowHuman implements Human {
public void getColor(){
System.out.println("黄色人种的皮肤颜色是黄色的！");
}
public void talk() {
System.out.println("黄色人种会说话，一般说的都是双字节。");
}
}
public abstract class AbstractHumanFactory {
public abstract <T extends Human> T createHuman(Class<T> c);
}
public class HumanFactory extends AbstractHumanFactory {
public <T extends Human> T createHuman(Class<T> c){
//定义一个生产的人种
Human human=null;
try {
//产生一个人种
human = (Human)Class.forName(c.getName()).newInstance();
} catch (Exception e) {
System.out.println("人种生成错误！");
}
return (T)human;
}
}
public class NvWa {
public static void main(String[] args) {
//声明阴阳八卦炉
AbstractHumanFactory YinYangLu = new HumanFactory();
//女娲第一次造人
System.out.println("--造出的第三批人是白色人种--");
Human whiteHuman = YinYangLu.createHuman(WhiteHuman.class);
whiteHuman.getColor();
whiteHuman.talk();
//女娲第二次造人
System.out.println("\n--造出的第三批人是黑色人种--");
Human blackHuman = YinYangLu.createHuman(BlackHuman.class);
blackHuman.getColor();
blackHuman.talk();
//第三次造人
System.out.println("\n--造出的第三批人是黄色人种--");
Human yellowHuman = YinYangLu.createHuman(YellowHuman.class);
yellowHuman.getColor();
yellowHuman.talk();
}
}