MD5的加密和解密

 

MD5的加密和解密：

 

import java.security.MessageDigest;

public class MD5andJM {
	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();
	}

	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;
	}

	public static void main(String args[]) {
		String s = new String("a");
		System.out.println("原始： " + s);
		System.out.println("MD5后： " + MD5(s));
		System.out.println("解密的： " + JM(JM(s)));
	}

}

 

 

 

 

 

结果：

原始： a
MD5后： 0cc175b9c0f1b6a831c399e269772661
解密的： a