练习11：（3）修改 Detergent.java,让它使用代理。
一：我的答案：
1 package com.learnJava.test;
2
3 /**
4 * @Author zhuchangli
5 * @Date 2019/9/15
6 **/
7 public class DetergentDelegation {
8
9 private Cleanser cleanser = new Cleanser();
10 private String s = "Cleanser ";
11 public void scrub(){
12 cleanser.append(" Detergent.scrub()");
13 cleanser.scrub();
14 }
15
16 public void append(String a){
17 cleanser.append(a);
18 }
19
20 public void dilute(){
21 cleanser.dilute();
22 }
23
24 public void apply(){
25 cleanser.applay();
26 }
27
28 public void foam(){
29 append("foam()");
30 }
31
32 public String toString(){
33 return cleanser.toString();
34 }
35
36 public static void main(String [] args){
37 DetergentDelegation d = new DetergentDelegation();
38 d.dilute();
39 d.apply();
40 d.scrub();
41 d.foam();
42 System.out.println(d);
43 System.out.println("Testing base class");
44 Cleanser.main(args);
45
46 }
47 }
运行结果：
Cleanserdilute()applay() Detergent.scrub()scrub()foam()
Testing base class
Cleanserdilute()applay()scrub()
使用继承时：
1 package com.learnJava.test;
2
3 /**
4 * @Author zhuchangli
5 * @Date 2019/9/14
6 **/
7 class Cleanser{
8 private String s = "Cleanser";
9 public void append(String a) { s += a; }
10 public void dilute(){ append("dilute()"); }
11 public void applay(){append("applay()");}
12 public void scrub(){append("scrub()");}
13 public String toString(){return s;}
14
15 public static void main(String [] args){
16 Cleanser x = new Cleanser();
17 x.dilute();
18 x.applay();
19 x.scrub();
20 System.out.println(x);
21 }
22 }
23 //洗涤剂
24 public class Detergent extends Cleanser{
25 public void scrub(){
26 append("Detergent.scrub()");
27 super.scrub();
28 }
29
30 // foam 泡沫
31 public void foam(){ append("foam()");}
32
33 public static void main(String [] args){
34 Detergent x = new Detergent();
35 x.dilute();
36 x.applay();
37 x.scrub();
38 x.foam();
39 System.out.println(x);
40 System.out.println("Testing base class");
41 Cleanser.main(args);
42 }
43 }
运行结果：
Cleanserdilute()applay()Detergent.scrub()scrub()foam()
Testing base class
Cleanserdilute()applay()scrub()
二：参考答案
1 package com.learnJava.test;
2
3 /**
4 * @Author zhuchangli
5 * @Date 2019/9/15
6 **/
7
8 class Cleanser11{
9 private String s = "Cleanser11";
10 public void append(String a) { s += a;}
11 public void dilute() {append(" dilute()");}
12 public void apply() {append(" apply()");}
13 public void scrub() {append(" scrub()");}
14 public String toString() {return s;}
15
16 public static void main(String [] args){
17 Cleanser11 x = new Cleanser11();
18 x.dilute();
19 x.apply();
20 x.scrub();
21 System.out.println(x);
22 }
23 }
24
25 public class DetergentDelegation11 {
26
27 private String s = "DetergentDelegation11 ";
28 private Cleanser11 c11 = new Cleanser11();
29
30 public void append(String a){
31 s += a;
32 }
33
34 public void dilute(){
35 c11.dilute();
36 }
37
38 public void apply() {c11.apply();}
39
40 public void scrub() {
41 append("DetergentDelegation11");
42 c11.scrub();
43 }
44
45 public void foam(){
46 append(" foam()");
47 }
48
49 public String toString(){
50 return s + " " + c11;
51 }
52
53 public static void main(String [] args){
54 DetergentDelegation11 d = new DetergentDelegation11();
55 d.dilute();
56 d.apply();
57 d.scrub();
58 d.foam();
59 System.out.println(d);
60 System.out.println("Testing base class");
61 Cleanser11.main(args);
62 }
63
64
65 }
运行结果：
DetergentDelegation11 DetergentDelegation11 foam() Cleanser11 dilute() apply() scrub()
Testing base class
Cleanser11 dilute() apply() scrub()
总结：
代理是什么：
将一个成员置于所要构造的类中，在新类中暴露了该成员对象的所有方法。
只提供在成员对象的方法的某个子集。