java-访问修饰符

                  同一个类中      同一个包中      不同包中的子类中   不同包中

private               OK                             

(default)            OK                     OK

protected           OK                     OK                       OK

public                 OK                     OK                       OK                              OK

package com.demo.test1;

import org.junit.Test;

/**
 * 类内
 * @author Administrator
 *
 */
public class Person {
    public String uname = "王五";
    @Test
    public void introduceMyself(){
        System.out.println(uname);
    }
}

package com.demo.test1;

import org.junit.Test;
/**
 * 同一个包
 * @author Administrator
 *
 */
public class Student {
    Person p = new Person();
    @Test
    public void test(){
        System.out.println(p.uname);
    }
}

package com.demo.test2;

import org.junit.Test;

import com.demo.test1.Person;
/**
 * 不同包
 * @author Administrator
 *
 */
public class Parents {
    public String uname = "haha";
    
    Person p = new Person();
    @Test
    public void test2(){
        //把uname用protected修饰，挎包不能访问uname属性
        //System.out.println(p.uname);
        //System.out.println(p.uname);
    
    }
}

package com.demo.test2;

import org.junit.Test;

import com.demo.test1.Person;
/**
 * 不同包的子类
 * @author Administrator
 *
 */
public class Man extends Person{
    public int age;
    Man m = new Man();
    Person p = new Person();
    
    @Test
    public void test3(){
        //当前类调用父类属性（protected修饰）
        System.out.println(m.uname);
        System.out.println(((Man)p).uname);
    }
}