文件加密解密encrypt

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.security.InvalidKeyException;
import java.security.Key;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.spec.InvalidKeySpecException;

import javax.crypto.Cipher;
import javax.crypto.CipherInputStream;
import javax.crypto.CipherOutputStream;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;
import javax.crypto.spec.SecretKeySpec;

public class encrypt {
    /**
    * 
    * @param srcfilepath 需要加密/解密的原文件
    * @param destfilepath 加密/解密后的目标文件
    * @param keystr 8位字符以上的密钥
    * @param isencrypt 加密/解密状态位-true为加密，false为解密
    * @throws exception 异常
    */

    public static void filedes(String srcfilepath,String destfilepath,Cipher cipher)throws Exception{

    String algorithm = "DES";
    
    File srcfile = new File(srcfilepath);
    File destfile = new File(destfilepath);
    byte[]tempbuffer=new byte[2048];
    
    FileInputStream inputfile = new FileInputStream(srcfile);
    FileOutputStream outputfile = new FileOutputStream(destfile);

    //加密或解密
    CipherInputStream cins = new CipherInputStream(inputfile,cipher);

       for(int n =0;(n=cins.read(tempbuffer))!=-1;){
        outputfile.write(tempbuffer,0,n);
       };
       inputfile.close();
       outputfile.close();
       cins.close();
    }

    /**
     * 返回DES解码的密钥
     * 
     * @param serialNumber
     *            机器序列号
     * @return 密钥
     */
    public static Key getKey(String serialNumber) {
        Key secretKey = null;
        try {
            MessageDigest md5 = MessageDigest.getInstance("MD5");
            md5.update(serialNumber.getBytes());
            DESKeySpec dks = new DESKeySpec(md5.digest());
            SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
            secretKey = keyFactory.generateSecret(dks);
        } catch (Exception e) {
            System.out.println("获取密码错误......");
        } 
        return secretKey;
    }
    public static void endir(String path,Cipher cipher) throws Exception{
        File file = new File(path);
        File[] filelistFiles = file.listFiles();
        for(int i = 0; i<filelistFiles.length ; i++){
            if(filelistFiles[i].isDirectory()){
                endir(filelistFiles[i].getPath(),cipher);
            }else{
                String enfilrpath;
                String filename = filelistFiles[i].getName();
                File dirFile = new File("D:\\TEST2\\"+
                        filelistFiles[i].getParentFile().getName()+"加密");
                if(!dirFile.exists())
                    dirFile.mkdirs();
                enfilrpath = dirFile.getPath()+File.separator+filename.substring(0, filename.length()-4)+
                                ".o"+filename.substring(filename.length()-3,filename.length());
                filedes(filelistFiles[i].getPath(),enfilrpath,cipher);
            }
        }
    }
    /**
    * @param args
     * @throws NoSuchPaddingException 
     * @throws NoSuchAlgorithmException 
    * @throws exception 
    */

    public static void main(String[] args)   {
    String path1 = "F:\\TEST1";
    String path2 = "F:\\TEST2";
    String serialNumber  = "fghfghrty";
    Boolean isencrypt = true;
    System.out.println("加密开始......");
    //产生钥匙
    Key key = getKey(serialNumber);
    //产生钥匙
    Cipher cipher = null;
    try {
        cipher = Cipher.getInstance("DES");
        if(isencrypt){
            //加密算法
            cipher.init(Cipher.ENCRYPT_MODE,key);
        }else{
            //解密算法
            cipher.init(Cipher.DECRYPT_MODE,key);
        }
    } catch (Exception e) {    
        System.out.println("加密开始错误......");
    } 
    try {
        if(cipher == null)
            return;
        endir(path1,cipher);

    } catch (Exception e) {
        System.out.println("加密错误......");
    }
    System.out.println("加密结束......");
    }
}