使用java自带des加密算法实现文件加密和字符串加密

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 )); }}