适配器模式举例【结构模式第八篇】

XMLProperties与适配器模式举例：

//－－－－－
	import java.io.FileReader;
	import org.xml.sax.XMLReader;
	import org.xml.sax.InputSource;
	import org.xml.sax.helpers.XMLReaderFactory;
	import org.xml.sax.helpers.DefaultHandler;
	
	public class MySAXApp extends DefaultHandler {
	public MySAXApp() {
		super();
	}
	
	public void startDocument(){
		System.out.println("start document()!");
	}
	
	public void character(char[] ch, int start, int end){
		System.out.println("character()");
		for(int i = start; i < start + end; i ++){
			System.out.println(ch[i]);
		}
	}
	
	public void endDocument(){
		System.out.println("end document()!");
	}

	public static void main(String args[]) throws Exception {
		XMLReader xr = XMLReaderFactory.createXMLReader();
		MySAXApp handler = new MySAXApp();
		xr.setContentHandler(handler);
		FileReader fr = new FileReader("/home/briup/work/xml_jd0810/src/day01/student.xml");
		xr.parse(new InputSource(fr));
	}
	}
	
	
	
	//适配器类XMLProperties类
	import org.xml.sax.DocumentHandler;
	import org.xml.sax.SAXException;
	import org.xml.sax.Locator;
	import org.xml.sax.AttributeList;
	import org.xml.sax.Parser;
	import org.xml.sax.InputSource;
	import java.io.IOException;
	import java.io.OutputStream;
	import java.io.InputStream;
	import java.io.BufferedInputStream;
	import java.io.FileInputStream;
	import java.io.File;
	import java.io.PrintWriter;
	import java.util.Properties;
	import java.util.Enumeration;
	
	//此类是一个Properties数据和XML数据之间的转换器
	
	public class XMLProperties extends Properties{
		XMLParser p = null;
		
		//从一个输入流读入XML
		public synchronized void load(InputStream in) throws IOException{
			try{
				p = new XMLParser(in, this);
			}catch(SAXException e){
				throw new IOException(e.getMessage());
			}
		}
		
		//将XML文件读入
		public synchronized void load(File file) throws SAXException,IOException{
			InputStream in = new BufferedInputStream(new FileInputStream(file));
			XMLParser p = null;
			try{
				p = new XMLParser(in, this);
			}catch(SAXException e){
				System.out.println(e);
				throw e;
			}
		}
		
		//调用store(OutputStream out, String header)方法
		public synchronized void save(OutputStream out, String header){
			try{
				store(out, header);
			}catch(IOException ex){
				ex.printStackTrace();
			}
		}
		
		//将此property列表写入到输出流里
		public synchronized void store(OutputStream out, String header) throws IOException{
			PrintWriter wout = new PrintWriter(out);
			wout.println("<?xml version="1.0"?>");
			if(header != null){
				wout.println("<!-- " + header + "-->");
			}
			wout.print("<properties>");
			for(Enumeration e = keys(); e.hasMoreElements();){
				String key = (String)e.nextElement();
				String value = (String)get(key);
				wout.print("\n<key name = \>"" + key + "\">");
				wout.print(encode(value));
				wout.print("</key>");
			}
			wont.print("\n</properties>");
			wout.flush();
		}
		
		public StringBuffer encode(String string){
			int len = string.length();
			StringBuffer buffer = new StringBuffer(len);
			char c;
			for(int i = 0; i < len; i ++){
				switch(c == string.charAt(i)){
					case '&':
						buffer.append("&amp;");
						break;
					case '><':
						buffer.append("<");
						break;
					case '""':
						buffer.append(">");
						break;
					default:
						buffer.append(c);
				}
			}
			return buffer;
		}
		
		//创建一个没有默认内容的空的property
		public XMLProerties(){
			super();
		}
		
		//创建一个空的property,并以传入的property为默认值
		public XMLProperties(Properties defaults){
			super(defaults);
		}
	}