适配器模式

  1 //目标抽象类
  2 public abstract class DataOperation
  3 {
  4     private String password;
  5     
  6     public void setPassword(String password)
  7     {
  8         this.password=password;
  9     }
 10         
 11     public String getPassword()
 12     {
 13         return this.password;
 14     }
 15     
 16     public abstract String doEncrypt(int key,String ps);
 17 }
 18 
 19 //适配者类
 20 public final class Caesar 
 21 {
 22     public String doEncrypt(int key,String ps)
 23     {   
 24         String es="";
 25         for(int i=0;i<ps.length();i++)
 26         {
 27             char c=ps.charAt(i);
 28             if(c>=‘a‘&&c<=‘z‘)
 29             {
 30                 c+=key%26;
 31             if(c>‘z‘) c-=26;
 32             if(c<‘a‘) c+=26;
 33             }
 34             if(c>=‘A‘&&c<=‘Z‘)
 35             {
 36                 c+=key%26;
 37             if(c>‘Z‘) c-=26;
 38             if(c<‘A‘) c+=26;
 39             }
 40             es+=c;
 41         }
 42         return es;
 43     }
 44 }
 45 
 46 //适配器类
 47 public class CipherAdapter extends DataOperation
 48 {
 49     private Caesar cipher;
 50     
 51     public CipherAdapter()
 52     {
 53         cipher=new Caesar();
 54     }
 55     
 56     public String doEncrypt(int key,String ps)
 57     {
 58         return cipher.doEncrypt(key,ps);
 59     }
 60 }
 61 
 62 //新适配者类
 63 public final class NewCipher
 64 {
 65     public String doEncrypt(int key,String ps)
 66     { 
 67         String es="";
 68         for(int i=0;i<ps.length();i++)
 69         {
 70             String c=String.valueOf(ps.charAt(i)%key);
 71             es+=c;
 72         }
 73         return es;
 74     }
 75 }
 76 
 77 //新适配器类
 78 public class NewCipherAdapter extends DataOperation
 79 {
 80     private NewCipher cipher;
 81     
 82     public NewCipherAdapter()
 83     {
 84         cipher=new NewCipher();
 85     }
 86     
 87     public String doEncrypt(int key,String ps)
 88     {
 89         return cipher.doEncrypt(key,ps);
 90     }
 91 }
 92 
 93 //配置文件 config.xml
 94 <?xml version="1.0"?>
 95 <config>
 96     <className>NewCipherAdapter</className>
 97 </config>
 98 
 99 //使用JAVA反射得到配置文件中的适配器类实例
100 import javax.xml.parsers.*;
101 import org.w3c.dom.*;
102 import org.xml.sax.SAXException;
103 import java.io.*;
104 public class XMLUtil
105 {
106 //该方法用于从XML配置文件中提取具体类类名，并返回一个实例对象
107     public static Object getBean()
108     {
109         try
110         {
111             //创建文档对象
112             DocumentBuilderFactory dFactory = DocumentBuilderFactory.newInstance();
113             DocumentBuilder builder = dFactory.newDocumentBuilder();
114             Document doc;                            
115             doc = builder.parse(new File("config.xml")); 
116         
117             //获取包含类名的文本节点
118             NodeList nl = doc.getElementsByTagName("className");
119             Node classNode=nl.item(0).getFirstChild();
120             String cName=classNode.getNodeValue();
121             
122             //通过类名生成实例对象并将其返回
123             Class c=Class.forName(cName);
124               Object obj=c.newInstance();
125             return obj;
126            }   
127                catch(Exception e)
128                {
129                    e.printStackTrace();
130                    return null;
131                }
132         }
133 }
134 
135 //客户端
136 public class Client
137 {
138     public static void main(String args[])
139     {
140         DataOperation dao=(DataOperation)XMLUtil.getBean();
141         dao.setPassword("sunnyLiu");
142         String ps=dao.getPassword();
143         String es=dao.doEncrypt(6,ps);
144         System.out.println("明文为：" + ps);
145         System.out.println("密文为：" + es);
146     }
147 }