利用反射来实现简单的工厂方法

记录一下学习工厂方法的心得

工厂方法能更方便的为我们实例化对象。

先定义接口

package com.sunny.project.factory;

public interface Student {
    public void introduceSelf();
}

简单弄两个实现类

package com.sunny.project.factory;

public class S1 implements Student {
    @Override
    public void introduceSelf() {
        System.out.println("大家好，我叫小虎！");
    }
}

package com.sunny.project.factory;

public class S2 implements Student {
    @Override
    public void introduceSelf() {
        System.out.println("大家好，我叫小文丽！");
    }
}

接下来写我们的工厂类：这里我们用到反射机制通过类名来是实例化对象

package com.sunny.project.factory;

public class StudentFactory {
    public Student getStudentByClass(String className) throws ClassNotFoundException, IllegalAccessException, InstantiationException {
        Student student=(Student) Class.forName(className).newInstance();
        return student;
    }
}

测试一下 需要注意这里的类名要写全名，只写单个类名会报错找不到该类。

package com.sunny.project.factory;

public class factoryTest {
    public static void main(String[] args){
        try {
            Student student=new StudentFactory().getStudentByClass("com.sunny.project.factory.S2");
            student.introduceSelf();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InstantiationException e) {
            e.printStackTrace();
        }
    }
}

结果没问题，我们只需要类名便可实例化出对象。最后不得不感慨反射真的很强大！