Implementation example of DES encryption and decryption tool class in Java

package lsy; import java.security.Key; import java.security.SecureRandom; import javax.crypto.Cipher; import javax.crypto.KeyGenerator; import javax.crypto.SecretKey; import sun.misc.BASE64Decoder; import sun.misc.BASE64Encoder; public class DesUtil { /** * @param args */ public static void main(String[] args) { //以下是加密方法algorithm="AES"的测试 System.out.println(DesUtil.getInstance("lushuaiyin").getEnCodeString("hello")); //输出 LDewGAZkmWHeYFjBz56ylw== //将上面的密文解密： System.out.println(DesUtil.getInstance("lushuaiyin").getDecodeString("LDewGAZkmWHeYFjBz56ylw==")); //输出 hello //改变密钥测试 System.out.println(DesUtil.getInstance("suolong").getEnCodeString("hello")); //输出 /RLowOJ+Fr3KdMcdJeNatg== System.out.println(DesUtil.getInstance("suolong").getDecodeString("/RLowOJ+Fr3KdMcdJeNatg==")); //输出 hello //如果使用不正确的密钥解密，将会： System.out.println(DesUtil.getInstance("suolong").getDecodeString("LDewGAZkmWHeYFjBz56ylw==")); } private SecretKey key=null;//密钥 //定义 加密算法,可用 DES,DESede,Blowfish,AES //不同的加密方式结果会不同 private static String algorithm="AES"; private static DesUtil desUtil=null; public DesUtil(){} public static DesUtil getInstance(String strKey){ desUtil=new DesUtil(); desUtil.createKey(strKey); return desUtil; } /** * algorithm 算法 * @param strKey */ public void createKey(String strKey){ try{ KeyGenerator kg=KeyGenerator.getInstance(DesUtil.algorithm); byte[] bt=strKey.getBytes("UTF-8"); SecureRandom sr=new SecureRandom(bt); kg.init(sr); this.setKey(kg.generateKey()); }catch(Exception e){ } } /** * 加密方法，返回密文 * cipher 密码 * @param dataStr */ public String getEnCodeString(String dataStr){ byte[] miwen=null;//密文 byte[] mingwen=null;//明文 Cipher cipher; String result="";//密文字符串 try{ mingwen=dataStr.getBytes("UTF-8"); cipher=Cipher.getInstance(DesUtil.algorithm); cipher.init(Cipher.ENCRYPT_MODE, this.getKey()); miwen=cipher.doFinal(mingwen); BASE64Encoder base64en = new BASE64Encoder(); result=base64en.encodeBuffer(miwen);//或者可以用下面的方法得到密文，结果是不一样的，都可以正常解密 // result=byte2hex(miwen);//密文结果类似2C:37:B0:18:06:64:99:61:DE:60:58:C1:CF:9E:B2:97 }catch(Exception e){ e.printStackTrace(); } return result; } /** * 解密方法，返回明文 * @param codeStr * @return */ public String getDecodeString(String codeStr){ BASE64Decoder base64De = new BASE64Decoder(); byte[] miwen=null; byte[] mingwen=null; String resultData="";//返回的明文 Cipher cipher; try{ miwen=base64De.decodeBuffer(codeStr); cipher=Cipher.getInstance(DesUtil.algorithm); cipher.init(Cipher.DECRYPT_MODE, this.getKey()); mingwen=cipher.doFinal(miwen); resultData = new String(mingwen,"UTF-8"); }catch(Exception e){ return "密钥不正确或其他原因导致异常，无法解密！"; } return resultData; } //二行制转字符串 public String byte2hex(byte[] b) { String hs = ""; String stmp = ""; for (int n = 0; n < b.length; n++) { stmp = (java.lang.Integer.toHexString(b[n] & 0XFF)); if (stmp.length() == 1) hs = hs + "0" + stmp; else hs = hs + stmp; if (n < b.length - 1) hs = hs + ":"; } return hs.toUpperCase(); } public SecretKey getKey() { return key; } public void setKey(SecretKey key) { this.key = key; } public static String getAlgorithm() { return algorithm; } public static void setAlgorithm(String algorithm) { algorithm = algorithm; } }

LDewGAZkmWHeYFjBz56ylw== hello /RLowOJ+Fr3KdMcdJeNatg== hello 密钥不正确或其他原因导致异常，无法解密！