md5加密及解密
阿新 • • 發佈:2018-12-04
md5加密及解密
package jiemibao; import java.security.MessageDigest; public class MD5andKL { // MD5加碼。32位 public static String MD5(String inStr) { MessageDigest md5 = null ; try { md5 = MessageDigest.getInstance("MD5" ); } catch (Exception e) { System.out.println(e.toString()); e.printStackTrace(); return "" ; } char [] charArray = inStr.toCharArray(); byte [] byteArray = new byte [charArray.length]; for ( int i = 0 ; i < charArray.length; i++) byteArray[i] = (byte ) charArray[i]; byte [] md5Bytes = md5.digest(byteArray); StringBuffer hexValue = new StringBuffer(); for ( int i = 0 ; i < md5Bytes.length; i++) { int val = (( int ) md5Bytes[i]) & 0xff ; if (val < 16 ) hexValue.append("0" ); hexValue.append(Integer.toHexString(val)); } return hexValue.toString(); } // 可逆的加密演算法 public static String KL(String inStr) { // String s = new String(inStr); char [] a = inStr.toCharArray(); for ( int i = 0 ; i < a.length; i++) { a[i] = (char ) (a[i] ^ 't' ); } String s = new String(a); return s; } // 加密後解密 public static String JM(String inStr) { char [] a = inStr.toCharArray(); for ( int i = 0 ; i < a.length; i++) { a[i] = (char ) (a[i] ^ 't' ); } String k = new String(a); return k; } // 測試主函式 public static void main(String args[]) { String s = new String( "zhangmia" ); System.out.println("原始:" + s); System.out.println("MD5後:" + MD5(s)); // System.out.println("MD5後再加密:" + KL(MD5(s))); System.out.println("解密為MD5後的:" + JM(KL(MD5(s)))); } }