JAVA采用DES算法进行加密解密文件

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package key;     import java.io.FileInputStream;  import java.io.FileOutputStream;  import java.io.InputStream;  import java.io.OutputStream;  import java.security.Key;  import java.security.SecureRandom;     import javax.crypto.Cipher;  import javax.crypto.CipherInputStream;  import javax.crypto.CipherOutputStream;  import javax.crypto.KeyGenerator;     public class key {     Key key;     public key(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) {           System.out.println();          cos.write(buffer, 0, r);       }       cos.close();       out.close();       is.close();     }     public static void main(String[] args) throws Exception {       key td = new key("aaa");            td.decrypt("D:/gx.txt", "d:/r1.txt"); //解密            }   }
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