通过反射（类类型）创建类的实例，调用类的方法，设置类的属性

Bean工厂

package com.test;

import java.lang.reflect.Field;
import java.lang.reflect.Method;

/**
 * Bean工厂
 */
public class BeanFactory {

    /**
     * 创建实例
     *
     * @param clazz
     * @return
     */
    public static Object newInstance(Class<?> clazz) {
        Object instance;
        try {
            instance = clazz.newInstance();
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
        return instance;
    }

    /**
     * 方法调用
     *
     * @param obj
     * @param method
     * @param args
     * @return
     */
    public static Object invokeMethod(Object obj, Method method, Object... args) {
        Object result;
        try {
            method.setAccessible(true);
            result = method.invoke(obj, args);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
        return result;
    }

    /**
     * 设置成员变量值
     *
     * @param obj
     * @param field
     * @param value
     */
    public static void setField(Object obj, Field field, Object value) {
        try {
            field.setAccessible(true);
            field.set(obj, value);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }
    
}

1. method.setAccessible(true);
2. field.setAccessible(true);

使私有的成员和方法可以访问

测试

package com.test;

public class Student {

	
	private int id;
	

	public int getId() {
		return id;
	}

	public void setId(int id) {
		this.id = id;
	}


	 
}

package com.test;

import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;

public class Test {

	public static void main(String[] args) throws ClassNotFoundException, IllegalArgumentException, IllegalAccessException {
		
		Class cl = Class.forName("com.test.Student");  
		//获得Student类的类类型
		
		//通过类类型创建Student类的实例
		Student student= (Student) BeanFactory.newInstance(cl);
		
		//获得类中定义的属性
		  Field[] beanFields = cl.getDeclaredFields();
		  //遍历属性
		  for (Field beanField : beanFields) {
			  //设置属性，依赖注入的影子
			BeanFactory.setField(student, beanField, Integer(1));
		  }
		  System.out.println(student.getId());
//		  
//		BeanFactory.setField(student, "name", "king");
		
    
       }

	private static Object Integer(int i) {
		// TODO Auto-generated method stub
		return i;
	}
}