import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.InputStream; import java.io.OutputStream; import java.security.SecureRandom; import javax.crypto.Cipher; import javax.crypto.CipherInputStream; import javax.crypto.SecretKey; import javax.crypto.SecretKeyFactory; import javax.crypto.spec.DESKeySpec; import javax.crypto.spec.IvParameterSpec; public class DesTool {  private static final String PASSKEY = "afasdf";  private static final String DESKEY = "asfsdfsdf";  /**   * @Comments ：对文件进行加密   * @param filePath  要加密的文件路径   * @param fileName 文件   * @param mode 加密模式  加密：Cipher.ENCRYPT_MODE 解密：Cipher.DECRYPT_MODE   * @return   */  public static String encoderOrdecoder(String filePath, String fileName, int mode) {   InputStream is = null;   OutputStream out = null;   CipherInputStream cis = null;   try {    SecureRandom sr = new SecureRandom();    DESKeySpec dks = new DESKeySpec(DESKEY.getBytes());    SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");    SecretKey securekey = keyFactory.generateSecret(dks);    IvParameterSpec iv = new IvParameterSpec(PASSKEY.getBytes());    Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");    cipher.init(mode, securekey, iv, sr);    File encoderFile = new File(filePath + File.separator + "encoder");    if (!encoderFile.exists()) {     encoderFile.mkdir();    }    is = new FileInputStream(filePath + File.separator + fileName);    out = new FileOutputStream(filePath + File.separator + "encoder"      + File.separator + fileName);    cis = new CipherInputStream(is, cipher);    byte[] buffer = new byte[1024];    int r;    while ((r = cis.read(buffer)) > 0) {     out.write(buffer, 0, r);    }   } catch (Exception e) {    e.printStackTrace();   } finally {    try {     if (is != null) {      is.close();     }     if (cis != null) {      cis.close();     }     if (out != null) {      out.close();     }    } catch (Exception e1){    }   }   return filePath + File.separator + "encoder" + File.separator     + fileName;  } /**@Comments ：对字符串进行加密  * @param src 源字符串  * @param mode 加密模式  加密：Cipher.ENCRYPT_MODE 解密：Cipher.DECRYPT_MODE  * @return  */ public static String encoderOrdecoder( String src, int mode) {   String tag="";   InputStream is = null;   OutputStream out = null;   CipherInputStream cis = null;   try {    SecureRandom sr = new SecureRandom();    DESKeySpec dks = new DESKeySpec(DESKEY.getBytes());    SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");    SecretKey securekey = keyFactory.generateSecret(dks);    IvParameterSpec iv = new IvParameterSpec(PASSKEY.getBytes());    Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");    cipher.init(mode, securekey, iv, sr);    cis = new CipherInputStream(new ByteArrayInputStream(src.getBytes()) , cipher);    out=new ByteArrayOutputStream();    byte[] buffer = new byte[1024];    int r;    while ((r = cis.read(buffer)) > 0) {     out.write(buffer, 0, r);    }    tag=out.toString();   } catch (Exception e) {    e.printStackTrace();   } finally {    try {     if (is != null) {      is.close();     }     if (cis != null) {      cis.close();     }     if (out != null) {      out.close();     }    } catch (Exception e1){    }   }   return tag;  }  public static void main(String[] args) {   System.out.println("aaa");    String t=encoderOrdecoder("aaa", Cipher.ENCRYPT_MODE );   System.out.println(t);    System.out.println(encoderOrdecoder(t, Cipher.DECRYPT_MODE ));  } }