读写SHA-1的问题

Question

我试图在文件内容的j​​ava中生成SHA-1然后读回来。一个十六进制数字变了，我不知道为什么？

代码： 写在文件中

//writer:
import java.util.*;
import java.io.*;
import java.security.*;

public class Writer{
    public static void main(String []args)throws Exception{


        InputStream  is =  new FileInputStream("input.txt");
        PrintStream os=new PrintStream(new File("out.txt"));
        byte[] buffer = new byte[1024];
        String str;
        MessageDigest complete = MessageDigest.getInstance("SHA-1");
        MessageDigest partial = MessageDigest.getInstance("SHA-1");
        int numRead;
        do {
             numRead = is.read(buffer);
             if (numRead > 0) {
                complete.update(buffer, 0, numRead);
                partial.update(buffer,0,numRead);

                byte []digest=partial.digest();
                StringBuilder sb = new StringBuilder();
                for (int i = 0; i < digest.length; i++) {

                    sb.append(String.format("%x", digest[i]));
                }
                System.out.println(sb.toString());
                str=new String(digest);
                os.println(str);
                partial.reset();
            }
        } while (numRead != -1);

        byte []digest=complete.digest();
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < digest.length; i++) {

           sb.append(String.format("%x", digest[i]));
        }
       System.out.println(sb.toString());
        str=new String(digest);
        os.println(str);


       is.close();
       os.close();
    }    
}

readfile的代码

//Reader:
    import java.util.*;
    import java.io.*;
    import java.security.*;
    public class Reader{
        public static void main(String []args)throws Exception{


            BufferedReader  is = new BufferedReader(new FileReader("out.txt"));
            String str;
            while((str=is.readLine())!=null)
            {
                //System.out.println(str);

                byte []digest=str.getBytes();
                StringBuilder sb = new StringBuilder();
                    for (int i = 0; i < digest.length; i++) {

                        sb.append(String.format("%x", digest[i]));
                    }
                    System.out.println(sb.toString());
            }

            is.close();
        }


    }

我使用另一个代码作为input.txt。它生成5个输出线。前4行读取和转换是可以的。最后一行带有更改的十六进制数字 inputfile中：input.txt中

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

/**
 *
 * @author biborno
 */
import java.io.*;
import java.security.*;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.SortedMap;
import java.util.TreeMap;
public class Torrent {
    private static void encodeObject(Object o, OutputStream out) throws IOException {
        if (o instanceof String)
            encodeString((String)o, out);
        else if (o instanceof Map)
            encodeMap((Map)o, out);
        else if (o instanceof byte[])
            encodeBytes((byte[])o, out);
        else if (o instanceof Number)
            encodeLong(((Number) o).longValue(), out);
        else
            throw new Error("Unencodable type");
    }
    private static void encodeLong(long value, OutputStream out) throws IOException {
        out.write('i');
        out.write(Long.toString(value).getBytes("US-ASCII"));
        out.write('e');
    }
    private static void encodeBytes(byte[] bytes, OutputStream out) throws IOException {
        out.write(Integer.toString(bytes.length).getBytes("US-ASCII"));
        out.write(':');
        out.write(bytes);
    }
    private static void encodeString(String str, OutputStream out) throws IOException {
        encodeBytes(str.getBytes("UTF-8"), out);
    }
    private static void encodeMap(Map<String,Object> map, OutputStream out) throws IOException{
        // Sort the map. A generic encoder should sort by key bytes
        SortedMap<String,Object> sortedMap = new TreeMap<String, Object>(map);
        out.write('d');
        for(Entry<String, Object> e : sortedMap.entrySet()) {
            encodeString(e.getKey(), out);
            encodeObject(e.getValue(), out);
        }
        out.write('e');
    }
    private static byte[] hashPieces(File file, int pieceLength) throws IOException {
        MessageDigest sha1;
        try {
            sha1 = MessageDigest.getInstance("SHA");
        } catch (NoSuchAlgorithmException e) {
            throw new Error("SHA1 not supported");
        }
        InputStream in = new FileInputStream(file);
        ByteArrayOutputStream pieces = new ByteArrayOutputStream();
        byte[] bytes = new byte[pieceLength];
        int pieceByteCount  = 0, readCount = in.read(bytes, 0, pieceLength);
        while (readCount != -1) {
            pieceByteCount += readCount;
            sha1.update(bytes, 0, readCount);
            if (pieceByteCount == pieceLength) {
                pieceByteCount = 0;
                pieces.write(sha1.digest());
            }
            readCount = in.read(bytes, 0, pieceLength-pieceByteCount);
        }
        in.close();
        if (pieceByteCount > 0)
            pieces.write(sha1.digest());
        return pieces.toByteArray();
    }
    public static void createTorrent(File file, File sharedFile, String announceURL) throws IOException {
        final int pieceLength = 512*1024;
        Map<String,Object> info = new HashMap<String,Object>();
        info.put("name", sharedFile.getName());
        info.put("length", sharedFile.length());
        info.put("piece length", pieceLength);
        info.put("pieces", hashPieces(sharedFile, pieceLength));
        Map<String,Object> metainfo = new HashMap<String,Object>();
        metainfo.put("announce", announceURL);
        metainfo.put("info", info);
        OutputStream out = new FileOutputStream(file);
        encodeMap(metainfo, out);
        out.close();
    }

    public static void main(String[] args) throws Exception {
        createTorrent(new File("C:\\Documents and Settings\\biborno\\Desktop\\Test.text.torrent"), new File("C:\\Documents and Settings\\biborno\\Desktop\\Test.text"), "http://example.com/announce");
    }
}

作者的输出：

f1556b25a651c3dc4831871ab3fce2d239c7f0d4
4ed5c741dbf78059fef3733340efcf9b16b4594f
e2b66127e6f25648e9e2d21cb18e26d4a541a17
26c213a35b3f2ccae28ad5e3b98b5a02386c368
e7d152cd8f5f22949abbc11eb049451c511df07b

out.txt：

ñUk%¦QÃÜH1‡³üâÒ9ÇðÔ
NÕÇAÛ÷€Yþós3@ïÏ›´YO
â¶a'æòVHéâÒ±Ž&Ô¥
&£[òÌ®(­^;˜µ #†Ãh
çÑRÍ?_"”š»Á°IEQð{

读者输出

f1556b25a651c3dc4831871ab3fce2d239c7f0d4
4ed5c741dbf78059fef3733340efcf9b16b4594f
e2b66127e6f25648e9e2d21cb18e26d4a541a17
26c213a35b3f2ccae28ad5e3b98b5a02386c368
e7d152cd3f5f22949abbc11eb049451c511df07b