记录一下代码片段

package cn.lcsd.zhx.util; import java.security.Key; import java.security.SecureRandom; import javax.crypto.Cipher; import javax.crypto.KeyGenerator; import sun.misc.BASE64Decoder; import sun.misc.BASE64Encoder; /** * 此类负责DES加密解密操作 * @author Hecheng * @time 2017-05-11 * @email hecheng@lchtime.com */ public class DesUtil { Key key; public DesUtil() { } public DesUtil(String str) { setKey(str); // 生成密匙 } public Key getKey() { return key; } public void setKey(Key key) { this.key = key; } /** * 根据参数生成 KEY */ public void setKey(String strKey) { try { KeyGenerator _generator = KeyGenerator.getInstance("DES"); // 防止linux下随机生成key SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG"); secureRandom.setSeed(strKey.getBytes()); _generator.init(56, secureRandom); this.key = _generator.generateKey(); _generator = null; } catch (Exception e) { throw new RuntimeException( "Error initializing SqlMap class. Cause: " + e); } } /** * 加密 String 明文输入 ,String 密文输出 */ public String encryptStr(String strMing) { byte[] byteMi = null; byte[] byteMing = null; String strMi = ""; BASE64Encoder base64en = new BASE64Encoder(); try { byteMing = strMing.getBytes("UTF8"); byteMi = this.encryptByte(byteMing); strMi = base64en.encode(byteMi); } catch (Exception e) { throw new RuntimeException( "Error initializing SqlMap class. Cause: " + e); } finally { base64en = null; byteMing = null; byteMi = null; } return strMi; } /** * 解密 以 String 密文输入 ,String 明文输出 * * @param strMi * @return */ public String decryptStr(String strMi) { BASE64Decoder base64De = new BASE64Decoder(); byte[] byteMing = null; byte[] byteMi = null; String strMing = ""; try { byteMi = base64De.decodeBuffer(strMi); byteMing = this.decryptByte(byteMi); strMing = new String(byteMing, "UTF8"); } catch (Exception e) { throw new RuntimeException( "Error initializing SqlMap class. Cause: " + e); } finally { base64De = null; byteMing = null; byteMi = null; } return strMing; } /** * 加密以 byte[] 明文输入 ,byte[] 密文输出 * * @param byteS * @return */ private byte[] encryptByte(byte[] byteS) { byte[] byteFina = null; Cipher cipher; try { cipher = Cipher.getInstance("DES/ECB/PKCS5Padding"); cipher.init(Cipher.ENCRYPT_MODE, key); byteFina = cipher.doFinal(byteS); } catch (Exception e) { throw new RuntimeException( "Error initializing SqlMap class. Cause: " + e); } finally { cipher = null; } return byteFina; } /** * 解密以 byte[] 密文输入 , 以 byte[] 明文输出 * @param byteD * @return */ private byte[] decryptByte(byte[] byteD) { Cipher cipher; byte[] byteFina = null; try { cipher = Cipher.getInstance("DES/ECB/PKCS5Padding"); cipher.init(Cipher.DECRYPT_MODE, key); byteFina = cipher.doFinal(byteD); } catch (Exception e) { throw new RuntimeException( "Error initializing SqlMap class. Cause: " + e); } finally { cipher = null; } return byteFina; } }