import java.security.MessageDigest;
public class MD5andKL {
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 "";
}
//一個新分配的字符數組,它的長度是此字符串的長度,而且內容被初始化爲包含此字符串表示的字符序列。
char[] charArray = inStr.toCharArray();
byte[] byteArray = new byte[charArray.length];
for (int i = 0; i < charArray.length; i++)
byteArray[i] = (byte) charArray[i];
//使用指定的字節數組對摘要進行最後更新,然後完成摘要計算,存放哈希值結果的字節數組。
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;
}
//測試主函數
public static void main (String args[]){
String s = new String("admin");
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("解密爲MD5後的:"+JM(KL(MD5(s))));
}
}