JAVA DES加密解密

import javax.crypto.KeyGenerator; import javax.crypto.CipherInputStream; import javax.crypto.Cipher; import javax.crypto.CipherOutputStream; import java.security.SecureRandom; import java.security.Key; import java.io.*; import java.security.*; /** * Created by IntelliJ IDEA. * User: 马千里 * Date: 2008-2-19 * Time: 8:52:29 * To change this template use File | Settings | File Templates. */ public class TestDES {   Key key;   public TestDES(String str) {     getKey(str);//生成密匙   }   /**   * 根据参数生成KEY   */   public void getKey(String strKey) {     try {         KeyGenerator _generator = KeyGenerator.getInstance("DES");         _generator.init(new SecureRandom(strKey.getBytes()));         this.key = _generator.generateKey();         _generator = null;     } catch (Exception e) {         throw new RuntimeException("Error initializing SqlMap class. Cause: " + e);     }   }   /**   * 文件file进行加密并保存目标文件destFile中   *   * @param file   要加密的文件 如c:/test/srcFile.txt   * @param destFile 加密后存放的文件名 如c:/加密后文件.txt   */   public void encrypt(String file, String destFile) throws Exception {     Cipher cipher = Cipher.getInstance("DES");     // cipher.init(Cipher.ENCRYPT_MODE, getKey());     cipher.init(Cipher.ENCRYPT_MODE, this.key);     InputStream is = new FileInputStream(file);     OutputStream out = new FileOutputStream(destFile);     CipherInputStream cis = new CipherInputStream(is, cipher);     byte[] buffer = new byte[1024];     int r;     while ((r = cis.read(buffer)) > 0) {         out.write(buffer, 0, r);     }     cis.close();     is.close();     out.close();   }   /**   * 文件采用DES算法解密文件   *   * @param file 已加密的文件 如c:/加密后文件.txt   *         * @param destFile   *         解密后存放的文件名 如c:/ test/解密后文件.txt   */   public void decrypt(String file, String dest) throws Exception {     Cipher cipher = Cipher.getInstance("DES");     cipher.init(Cipher.DECRYPT_MODE, this.key);     InputStream is = new FileInputStream(file);     OutputStream out = new FileOutputStream(dest);     CipherOutputStream cos = new CipherOutputStream(out, cipher);     byte[] buffer = new byte[1024];     int r;     while ((r = is.read(buffer)) >= 0) {         cos.write(buffer, 0, r);     }     cos.close();     out.close();     is.close();   }   public static void main(String[] args) throws Exception {     TestDES td = new TestDES("aaa");     td.encrypt("C:/Java实现文件的RSA和DES加密算法.doc", "c:/加密后文件1.doc"); //加密     td.decrypt("c:/加密后文件1.doc", "c:/解密后文件1.doc"); //解密   } }