java设计模式之简单工厂模式详解

public abstract class People {  public abstract void doSth();}

public class Man extends People{  @Override  public void doSth() {    System.out.println("I'm a man,I'm coding.");  }}

public class Girl extends People{  @Override  public void doSth() {    System.out.println("I'm a girl,I'm eating.");  }}

public class PeopleFactory {  public static People getSpecificPeople(String type){    if("A-Man".equals(type)){      return new Man();    }else if("B-Girl".equals(type)){      return new Girl();    }else {      return null;    }  }}

public class PeopleTestDemo {  public static void main(String[] args) {    People man = PeopleFactory.getSpecificPeople("A-Man");    Objects.requireNonNull(man,"对象不存在.");    man.doSth();    People girl = PeopleFactory.getSpecificPeople("B-Girl");    Objects.requireNonNull(girl,"对象不存在");    girl.doSth();    People foodie = PeopleFactory.getSpecificPeople("Foodie");    Objects.requireNonNull(foodie,"对象不存在");    foodie.doSth();  }}