1、新建抽象类AbstractUser

package com.kobe.model;public abstract class AbstractUser {public abstract void work();}

2、新建继承AbstractUser 的 AbstractStudent 、 AbstractTeacher

package com.kobe.model;public class AbstractTeacher extends AbstractUser{private int id;private String name;@Overridepublic void work(){System.out.println("teach");}public int getId() {return id;}public void setId(int id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}}

package com.kobe.model;public class AbstractStudent extends AbstractUser {private int id;private String name;@Overridepublic void work(){System.out.println("study");}public int getId() {return id;}public void setId(int id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}}

3、在resources目录下新建配置文件 obj.properties

AbstractModel = com.kobe.model.AbstractStudent

4、新建工厂类  getUser方法 从配置文件中读取配置信息

package com.kobe.test;import com.kobe.model.AbstractUser;import java.util.Properties;public class AbstractFactory {public static AbstractUser getUser(){try {Properties prop = new Properties();prop.load(simpleFactory.class.getClassLoader().getResourceAsStream("obj.properties"));String model = (String) prop.get("AbstractModel");AbstractUser u = (AbstractUser) Class.forName(model).newInstance();return u;} catch (Exception e) {e.printStackTrace();}return null;}}

5、新建测试类

package com.kobe.test;import com.kobe.model.AbstractUser;public class testAbstract {public static void main(String[] args) {AbstractUser u1 = AbstractFactory.getUser();u1.work();}
}

输出结果是  study

如果把配置文件中的 AbstractModel的值换成 com.kobe.model.AbstractTeacher

输出就变成 teach

根据配置文件创建不同的实体类，不需修改java代码