http://www.verejava.com/?id=16992895490365

包其实就是 文件夹 

1. 新建一个包 com.pack1 Eclipse 工程上单击右键 -> New -> Package 
   然后再 com.pack1 下面新建 Person 类 

package com.pack1;

import com.pack2.Wallet; // 文件夹路径 com/pack2/Wallet

public class Person {

    public Person() {
        Wallet w = new Wallet();
        System.out.println(w.getMoney());
    }

    public static void main(String[] args) {
        new Person();
    }
}


2. 新建一个包 com.pack2 
   在 com.pack2 包下面新建 Wallet 类 

package com.pack2;

public class Wallet {
    private double money;

    public void setMoney(double money) {
        this.money = money;
    }

    public double getMoney() {
        return this.money;
    }
}

http://www.verejava.com/?id=16992895490365