亚洲第一页综合图片自拍,国产精品亚洲综合专区片高清久久久 ,亚洲国产精品线观看不卡

protected訪問權限

1、protected的類、類屬變量及方法，包內的任何類，及包外的那些繼承了此類的子類才能訪問；

注意：子類如處于不同的包，則相互間不能訪問繼承自父類的方法。

所有不能訪問的方法都已經被注釋：

package packageA;
2

public class Base {
4

public String publicStr = "publicString";
5

protected String protectedStr = "protectedString";
6

String defaultStr = "defaultString";
7

private String privateStr = "privateString";
8

public void print() {
10

System.out.println("packageA.Base has access to");
11

System.out.println(" " + publicStr);
12

System.out.println(" " + protectedStr);
13

System.out.println(" " + defaultStr);
14

System.out.println(" " + privateStr);
15

Base b = new Base(); // -- other Base instance
17

System.out.println(" b." + b.publicStr);
18

System.out.println(" b." + b.protectedStr);
19

System.out.println(" b." + b.defaultStr);
20

System.out.println(" b." + b.privateStr);
21

}
22

}
23

--------------------------------------------------------------------------------
25

package packageA;
27

public class SubA extends Base {
29

public void print() {
30

System.out.println("packageA.SubA has access to");
31

System.out.println(" " + publicStr + " (inherited from Base)");
32

System.out.println(" " + protectedStr + " (inherited from Base)");
33

System.out.println(" " + defaultStr + " (inherited from Base)");
34

// -- not accessible - private elements are even not inherited
35

// System.out.println(privateStr);
36

Base b = new Base(); // -- other Base instance
38

System.out.println(" b." + b.publicStr);
39

System.out.println(" b." + b.protectedStr);
40

System.out.println(" b." + b.defaultStr);
41

// -- not accessible
42

// System.out.println(b.privateStr);
43

}
44

}
45

--------------------------------------------------------------------------------
47

package packageA;
49

public class AnotherA {
51

public void print() {
52

System.out.println("packageA.AnotherA has access to");
53

Base b = new Base();
54

System.out.println(" b." + b.publicStr);
55

System.out.println(" b." + b.protectedStr);
56

System.out.println(" b." + b.defaultStr);
57

// System.out.println(b.privateStr);
58

}
59

}
60

--------------------------------------------------------------------------------
62

package packageB;
64

import packageA.Base;
65

public class SubB extends Base {
67

public void print() {
68

System.out.println("packageB.SubB has access to");
69

System.out.println(" " + publicStr + " (inherited from Base)");
70

// -- protectedStr is inherited element -> accessible
71

System.out.println(" " + protectedStr + " (inherited from Base)");
72

// -- not accessible
73

// System.out.println(defaultStr);
74

// System.out.println(privateStr);
75

Base b = new Base(); // -- other Base instance
77

System.out.println(" b." + b.publicStr);
78

// -- protected element, which belongs to other object -> not accessible
79

// System.out.println(b.protectedStr);
80

// -- not accessible
82

// System.out.println(b.defaultStr);
83

// System.out.println(b.privateStr);
84

}
85

}
86

--------------------------------------------------------------------------------
88

package packageB;
90

import packageA.Base;
91

public class AnotherB {
93

public void print() {
94

System.out.println("packageB.AnotherB has access to");
95

Base b = new Base();
96

System.out.println(" b." + b.publicStr);
97

// -- not accessible
98

// System.out.println(b.protectedStr);
99

// System.out.println(b.defaultStr);
100

// System.out.println(b.privateStr);
101

}
102

}
103

104

--------------------------------------------------------------------------------
105

106

import packageA.*;
107

import packageB.*;
108

109

// -- testing class
110

public class TestProtection {
111

public static void main(String[] args) {
112

// -- all classes are public, so class TestProtection
113

// -- has access to all of them
114

new Base().print();
115

new SubA().print();
116

new AnotherA().print();
117

new SubB().print();
118

new AnotherB().print();
119

}
120

}
121

posted on 2009-02-21 19:39 何克勤閱讀(541) 評論(0) 編輯收藏所屬分類: J2SE

常用鏈接

留言簿(4)

我參與的團隊

隨筆分類

隨筆檔案

收藏夾

C++ 社區

常用網站

搜索

最新評論

閱讀排行榜

評論排行榜


只有注冊用戶登錄后才能發表評論。




網站導航: 博客園 IT新聞 Chat2DB C++博客博問管理
相關文章: 線程中釋放鎖的方式 Java線程 just-in-time編譯器 file的getPath getAbsolutePath和getCanonicalPath的不同 protected訪問權限關聯、組合、聚合、依賴關系比較比較分析Vector、ArrayList和hashtable hashmap數據結構 [轉]Java RPC通信機制之RMI (轉)Java中URI,URL和URN的使用關于java連接sql server 2000的問題