Java中許可權控制,import 和 package 關鍵字
概況表:
目錄結構為:我們在com.java17包下建立了兩個class:Demo01、Demo02。
舉例一:
Demo01:
package com.java17;
public class Demo01 {
private String name = "haohao"; public static void main(String[] args) { Demo01 java = new Demo01(); System.out.println(java.name); } }
//Demo01執行成功輸出 haohao
Demo02:
package com.java17;
public class Demo02 { public static void main(String[] args) { Demo01 java = new Demo01(); System.out.println(java.name); } } //Demo02執行失敗不能輸出 haohao
舉例二:
//Demo02呼叫Demo01的方法:
Demo01:
package com.java17;
public class Demo01 {
private String name; private int age; public void setname(String name) { this.name = name; } public String getname() { return this.name; } public void setage(int age) { this.age = age; } public int getage() { return this.age; } public static void main(String[] args) { Demo01 java = new Demo01(); System.out.println(java.name); } }
Demo02:
package com.java17;
public class Demo02 { public static void main(String[] args) { Demo01 java = new Demo01(); java.setname("浩浩"); java.setage(18); System.out.println("名字是:" + java.getname()); System.out.println("年齡為:" + java.getage()); } }