设计模式4:装饰模式(1)

 1 package com.qianfeng.decorator;
 2 
 3 public class Demo12 {
 4 
 5     public static void main(String[] args) {
 6         Person p1 = new Zhansan();
 7         p1.show();
 8 
 9         Person p2 = new JeansDecorator(p1);
10         p2.show();
11 
12         Person p3 = new ShirtDecorator(p1);
13         p3.show();
14     }
15 }
16 
17 interface Person {
18     void show();// 显示一个人
19 }
20 
21 abstract class DecoratorPerson implements Person {
22     private Person person;
23 
24     DecoratorPerson(Person person) {
25         this.person = person;
26     }
27 }
28 
29 class JeansDecorator extends DecoratorPerson {
30 
31     JeansDecorator(Person person) {
32         super(person);
33         // TODO Auto-generated constructor stub
34     }
35 
36     @Override
37     public void show() {
38         System.out.println("穿牛仔裤的person");
39 
40     }
41 }
42 
43 class ShirtDecorator extends DecoratorPerson {
44 
45     ShirtDecorator(Person person) {
46         super(person);
47         // TODO Auto-generated constructor stub
48     }
49 
50     @Override
51     public void show() {
52         System.out.println("穿t恤的person");
53 
54     }
55 
56 }
57 
58 class Zhansan implements Person {
59 
60     @Override
61     public void show() {
62         System.out.println("没有任何装饰的张三");
63 
64     }
65 
66 }

  1 package com.qianfeng.decorator;
  2 
  3 import java.io.FileReader;
  4 import java.io.IOException;
  5 import java.io.Reader;
  6 
  7 public class Demo13 {
  8     // LineNumberReader 装饰类，继承了BufferedReader
  9     public static void main(String[] args) throws IOException {
 10         FileReader fr = new FileReader("src/temp.txt");
 11         // LineNumberReader lnr = new LineNumberReader(fr);
 12         // String line = null;
 13         // lnr.setLineNumber(100);
 14         // while ((line = lnr.readLine()) != null) {
 15         // System.out.println(lnr.getLineNumber() + ":" + line);
 16         // }
 17         // lnr.close();
 18 
 19         MyLineNumberReader lnr = new MyLineNumberReader(fr);
 20         String line = null;
 21         // lnr.setLineNumber(1000);
 22         while ((line = lnr.MyReadLine()) != null) {
 23             System.out.println(lnr.getLineNumber() + ":" + line);
 24         }
 25         lnr.myClose();
 26     }
 27 
 28 }
 29 
 30 /*
 31  * setLineNumber():设置起始行号
 32  * 
 33  * myReadLine（）：每次读取一行
 34  * 
 35  * getLineNumber（）：获得当前行号
 36  */
 37 class MyBufferedReader {
 38     private Reader r; // 真正读取功能的类
 39     private char[] arr = new char[512];// 相当于缓冲区
 40     private int index; // 数组下标
 41     private int count; // 统计缓冲区中字符个数
 42 
 43     public MyBufferedReader(Reader r) {
 44         this.r = r;
 45     }
 46 
 47     // 实现一次读取一个的功能
 48     public int myRead() throws IOException {
 49         // 缓冲区中是否有数据
 50         if (count == 0) {
 51             // 从文件中读取数据到缓冲区，返回值读取的字符数
 52             count = r.read(arr);
 53             index = 0; // 下标为0
 54         }
 55         if (count < 0) // 文件末尾
 56             return -1;
 57         // 从缓冲区中读取一个字符
 58         int num = arr[index];
 59         index++;// 下标+1
 60         // 数量-1
 61         count--;
 62         return num;
 63 
 64     }
 65 
 66     // 一次读取一行
 67     public String myReadLine() throws IOException {
 68         StringBuilder sb = new StringBuilder();
 69         int num;
 70         while ((num = myRead()) != -1) {
 71             if (num == ‘\r‘)
 72                 continue;
 73             else if (num == ‘\n‘)
 74                 return sb.toString();
 75             else
 76                 sb.append((char) num);
 77         }
 78         return null;
 79     }
 80 
 81     // 关闭流
 82     public void myClose() throws IOException {
 83         r.close();
 84     }
 85 }
 86 
 87 class MyLineNumberReader extends MyBufferedReader {
 88 
 89     private int lineNumber;
 90 
 91     public MyLineNumberReader(Reader r) {
 92         super(r);
 93     }
 94 
 95     public void setLineNumber(int lineNumber) {
 96         this.lineNumber = lineNumber;
 97     }
 98 
 99     public int getLineNumber() {
100         return this.lineNumber;
101     }
102 
103     // 每次读取一行，行号+1
104     public String MyReadLine() throws IOException {
105         ++lineNumber;
106         return super.myReadLine();
107     }
108 
109 }