tculzw.java

为公司做的质量考核接口源码,用spring,hibernate,XML实现,对XML接口编程很有帮助

package com.jr81.source.compression;

/*
 * LZW.java
 *
 * Created on 01 Dec 2005
 *
 * Implementation of LZW compression/decompression algorithm
 */

import java.io.* ;
import java.util.zip.GZIPOutputStream;


/**
 *
 * @author  Moshe Fresko
 * @course	Algorithmic Programming 1
 * @exercise	3
 */

public class TcuLZW implements Compression
{
	boolean stopped = false ;

	Dict dict ;
		// The bits that should be written for each code
	int numOfBits ;
		// The previous string that we should remember
		// in order to insert into the dictionary
	final ByteArray emptyBA = new ByteArray() ;
	ByteArray w=emptyBA ;
		// Constructor gets the number of bits to be written for each code
	public TcuLZW()
	{
		numOfBits = 12 ;
			// Create a new Limited Dictionary
			// For maximum of 2^bits entries
		dict = new LimitedDict(1<<numOfBits) ;
			// Add all ascii characters to the dictionary
		for (int i=0;i<256;++i)
			dict.add(new ByteArray((byte)i)) ;
	}
		// Encodes the next character.
		// If there is a code generated returns it.
		// If not returns -1.
	int encodeOneChar(int n) {
		byte c = (byte) n ;
		ByteArray nw = w.conc(c) ;
		int code = dict.numFromStr(nw) ;
			// if it exists then we continue to search for a longer string
		if (code!=-1) {
			w = nw ;
			return -1 ;
		} else {
			dict.add(nw) ;
			nw = w ;
			w = new ByteArray(c) ;
			return dict.numFromStr(nw) ;
		}
	}
		// If there is something left in w, returns its code
	int encodeLast() {
		ByteArray nw = w ;
		w = emptyBA ;
		return dict.numFromStr(nw) ;
	}
		// Write the code in bits into output stream
	void writeCode(OutputStream os, int code) throws IOException
	{
		for (int i=0;i<numOfBits;++i) {
			os.write(code&1) ;
			code /= 2 ;
		}
	}

	int readCode(InputStream is) throws IOException
	{
		int num = 0 ;
		for (int i=0;i<numOfBits;++i) {
			int next = is.read() ;
			if (next<0)
				return -1 ;
			num += next<<i ;
		}
		return num ;
	}

	public void compress(InputStream is, OutputStream os) throws IOException {
		os = new BitOutputStream(os) ;
		int next ;	// next input character
		int code ;	// next code generated
		while ((next=is.read())>=0) {
			if (stopped)
				break ;
			code = encodeOneChar(next) ;
			if (code>=0)
				writeCode(os,code) ;
		}
		code = encodeLast() ;
		if (code>=0)
			writeCode(os,code) ;
    os.flush() ;
	}

	ByteArray decodeOne(int code) {
			// Either "ABA" or null, w="AB"
		ByteArray str = dict.strFromNum(code) ;
		if (str==null) {
			str = w.conc(w.getAt(0)) ;
			dict.add(str) ;
		} else
			if (! w.isEmpty())
				dict.add(w.conc(str.getAt(0))) ;
            w = str ;
		return w ;
	}

	public void decompress(InputStream is, OutputStream os) throws IOException {
		is = new BitInputStream(is) ;
		ByteArray str ;	// Next entry
		int code ;		// Next code to be read
		while ((code=readCode(is))>=0) {
			if (stopped)
				break ;
			str = decodeOne(code) ;
			os.write(str.getBytes()) ;
		}
	}

	public void stop()
		{ stopped = true ; }
	
	static final int BUFFER = 2048;

	public static void main(String[] args) throws IOException {
		// TODO Auto-generated method stub
		/*TcuLZW ld = new TcuLZW();
		FileInputStream file = new FileInputStream("c:\\dd.xml");
		FileOutputStream file1 = new FileOutputStream("c:\\dx.lz");
		ld.compress(file,file1);
		*/
		/*
		try{
            BufferedReader in=new BufferedReader(
                                new InputStreamReader(new FileInputStream("c:\\dd.xml"),"ISO8859_1"));
            FileOutputStream f=new FileOutputStream("c:\\dx.zip");
            CheckedOutputStream ch=new CheckedOutputStream(f,new CRC32());
            ZipOutputStream out=new ZipOutputStream(
                                   new BufferedOutputStream(ch));
     
           int c;
           out.putNextEntry(new ZipEntry("dd.xml"));
           while((c=in.read())!=-1)
               out.write(c);
             in.close();
             out.close();
           }
        catch(Exception e){
            e.printStackTrace();
           }
       */ 
       /* try {
        	BufferedOutputStream dest = null;
        	BufferedInputStream is = null;
        	ZipEntry entry;
        	ZipFile zipfile = new ZipFile("c:\\dx.zip");
        	Enumeration e = zipfile.entries();
        	while(e.hasMoreElements()) {
        	entry = (ZipEntry) e.nextElement();
        	System.out.println("Extracting: " +entry);
        	is = new BufferedInputStream
        	(zipfile.getInputStream(entry));
        	int count;
        	byte data[] = new byte[BUFFER];
        	FileOutputStream fos = new 
        	FileOutputStream("c:\\" + entry.getName());
        	dest = new 
        	BufferedOutputStream(fos, BUFFER);
        	while ((count = is.read(data, 0, BUFFER)) 
        	!= -1) {
        	dest.write(data, 0, count);
        	}
        	dest.flush();
        	dest.close();
        	is.close();
        	}
        	} catch(Exception e) {
        	e.printStackTrace();
        	}
       */
		try 
		{ 
//		打开需压缩文件作为文件输入流 
		FileInputStream fin=new FileInputStream("c:\\dd.xml"); 
//		建立压缩文件输出流 
		FileOutputStream fout=new FileOutputStream("c:\\dd1.zip"); 
//		建立gzip压缩输出流 
		GZIPOutputStream gzout=new GZIPOutputStream(fout); 
		byte[] buf=new byte[1024];//设定读入缓冲区尺寸 
		int num; 
		 
		while ((num=fin.read(buf)) != -1) 
		{ 
		gzout.write(buf,0,num); 
		} 
		gzout.close();//!!!关闭流,必须关闭所有输入输出流.保证输入输出完整和释放系统资源.
		 
		fout.close(); 
		fin.close(); 
		}catch(IOException e) 
		{ 
		System.out.println(e); 
		} 
		/*
		try 
		{ 
//		建立gzip压缩文件输入流 
		FileInputStream fin=new FileInputStream("c:\\ddd1.zip"); 
//		建立gzip解压工作流 
		GZIPInputStream gzin=new GZIPInputStream(fin); 
//		建立解压文件输出流 
		FileOutputStream fout=new FileOutputStream("c:\\ddd122.xml"); 
		byte[] buf=new byte[1024]; 
		int num; 
		 
		while ((num=gzin.read(buf,0,buf.length)) != -1) 
		{ 
		fout.write(buf,0,num); 
		} 
		gzin.close(); 
		fout.close(); 
		fin.close(); 
		}catch(IOException e) 
		{ 
		System.out.println(e); 
		} 
		*/
        	
   }

	
	
}