md5加密

package com.work.util;

/**
 * @author w
 * @date 2008-7-13下午01:52:57
 * 根据RFC 1321编写的md5编码，已经通过了验证。好用！
 * javascript实现的下载地址为：http://pajhome.org.uk/crypt/md5/
 */
public class MD5 {
	/*
	 * A Java implementation of the RSA Data Security, Inc. MD5 Message Digest
	 * Algorithm, as defined in RFC 1321. Based on the JavaScript implementation
	 * of Paul Johnston Copyright (C) Paul Johnston 1999 - 2000. See
	 * http://pajhome.org.uk/site/legal.html for details. Java Version by Thomas
	 * Weber (Orange Interactive GmbH)
	 */

	/*
	 * Convert a 32-bit number to a hex string with ls-byte first
	 */
	String hex_chr = "0123456789abcdef";

	private String rhex(int num) {
		String str = "";
		for (int j = 0; j <= 3; j++)
			str = str + hex_chr.charAt((num >> (j * 8 + 4)) & 0x0F)
					+ hex_chr.charAt((num >> (j * 8)) & 0x0F);
		return str;
	}

	/*
	 * Convert a string to a sequence of 16-word blocks, stored as an array.
	 * Append padding bits and the length, as described in the MD5 standard.
	 */
	private int[] str2blks_MD5(String str) {
		int nblk = ((str.length() + 8) >> 6) + 1;
		int[] blks = new int[nblk * 16];
		int i = 0;
		for (i = 0; i < nblk * 16; i++) {
			blks[i] = 0;
		}
		for (i = 0; i < str.length(); i++) {
			blks[i >> 2] |= str.charAt(i) << ((i % 4) * 8);
		}
		blks[i >> 2] |= 0x80 << ((i % 4) * 8);
		blks[nblk * 16 - 2] = str.length() * 8;

		return blks;
	}

	/*
	 * Add integers, wrapping at 2^32
	 */
	private int add(int x, int y) {
		return ((x & 0x7FFFFFFF) + (y & 0x7FFFFFFF)) ^ (x & 0x80000000)
				^ (y & 0x80000000);
	}

	/*
	 * Bitwise rotate a 32-bit number to the left
	 */
	private int rol(int num, int cnt) {
		return (num << cnt) | (num >>> (32 - cnt));
	}

	/*
	 * These functions implement the basic operation for each round of the
	 * algorithm.
	 */
	private int cmn(int q, int a, int b, int x, int s, int t) {
		return add(rol(add(add(a, q), add(x, t)), s), b);
	}

	private int ff(int a, int b, int c, int d, int x, int s, int t) {
		return cmn((b & c) | ((~b) & d), a, b, x, s, t);
	}

	private int gg(int a, int b, int c, int d, int x, int s, int t) {
		return cmn((b & d) | (c & (~d)), a, b, x, s, t);
	}

	private int hh(int a, int b, int c, int d, int x, int s, int t) {
		return cmn(b ^ c ^ d, a, b, x, s, t);
	}

	private int ii(int a, int b, int c, int d, int x, int s, int t) {
		return cmn(c ^ (b | (~d)), a, b, x, s, t);
	}

	/*
	 * Take a string and return the hex representation of its MD5.
	 */
	public String calcMD5(String str) {
		int[] x = str2blks_MD5(str);
		int a = 0x67452301;
		int b = 0xEFCDAB89;
		int c = 0x98BADCFE;
		int d = 0x10325476;

		for (int i = 0; i < x.length; i += 16) {
			int olda = a;
			int oldb = b;
			int oldc = c;
			int oldd = d;

			a = ff(a, b, c, d, x[i + 0], 7, 0xD76AA478);
			d = ff(d, a, b, c, x[i + 1], 12, 0xE8C7B756);
			c = ff(c, d, a, b, x[i + 2], 17, 0x242070DB);
			b = ff(b, c, d, a, x[i + 3], 22, 0xC1BDCEEE);
			a = ff(a, b, c, d, x[i + 4], 7, 0xF57C0FAF);
			d = ff(d, a, b, c, x[i + 5], 12, 0x4787C62A);
			c = ff(c, d, a, b, x[i + 6], 17, 0xA8304613);
			b = ff(b, c, d, a, x[i + 7], 22, 0xFD469501);
			a = ff(a, b, c, d, x[i + 8], 7, 0x698098D8);
			d = ff(d, a, b, c, x[i + 9], 12, 0x8B44F7AF);
			c = ff(c, d, a, b, x[i + 10], 17, 0xFFFF5BB1);
			b = ff(b, c, d, a, x[i + 11], 22, 0x895CD7BE);
			a = ff(a, b, c, d, x[i + 12], 7, 0x6B901122);
			d = ff(d, a, b, c, x[i + 13], 12, 0xFD987193);
			c = ff(c, d, a, b, x[i + 14], 17, 0xA679438E);
			b = ff(b, c, d, a, x[i + 15], 22, 0x49B40821);

			a = gg(a, b, c, d, x[i + 1], 5, 0xF61E2562);
			d = gg(d, a, b, c, x[i + 6], 9, 0xC040B340);
			c = gg(c, d, a, b, x[i + 11], 14, 0x265E5A51);
			b = gg(b, c, d, a, x[i + 0], 20, 0xE9B6C7AA);
			a = gg(a, b, c, d, x[i + 5], 5, 0xD62F105D);
			d = gg(d, a, b, c, x[i + 10], 9, 0x02441453);
			c = gg(c, d, a, b, x[i + 15], 14, 0xD8A1E681);
			b = gg(b, c, d, a, x[i + 4], 20, 0xE7D3FBC8);
			a = gg(a, b, c, d, x[i + 9], 5, 0x21E1CDE6);
			d = gg(d, a, b, c, x[i + 14], 9, 0xC33707D6);
			c = gg(c, d, a, b, x[i + 3], 14, 0xF4D50D87);
			b = gg(b, c, d, a, x[i + 8], 20, 0x455A14ED);
			a = gg(a, b, c, d, x[i + 13], 5, 0xA9E3E905);
			d = gg(d, a, b, c, x[i + 2], 9, 0xFCEFA3F8);
			c = gg(c, d, a, b, x[i + 7], 14, 0x676F02D9);
			b = gg(b, c, d, a, x[i + 12], 20, 0x8D2A4C8A);

			a = hh(a, b, c, d, x[i + 5], 4, 0xFFFA3942);
			d = hh(d, a, b, c, x[i + 8], 11, 0x8771F681);
			c = hh(c, d, a, b, x[i + 11], 16, 0x6D9D6122);
			b = hh(b, c, d, a, x[i + 14], 23, 0xFDE5380C);
			a = hh(a, b, c, d, x[i + 1], 4, 0xA4BEEA44);
			d = hh(d, a, b, c, x[i + 4], 11, 0x4BDECFA9);
			c = hh(c, d, a, b, x[i + 7], 16, 0xF6BB4B60);
			b = hh(b, c, d, a, x[i + 10], 23, 0xBEBFBC70);
			a = hh(a, b, c, d, x[i + 13], 4, 0x289B7EC6);
			d = hh(d, a, b, c, x[i + 0], 11, 0xEAA127FA);
			c = hh(c, d, a, b, x[i + 3], 16, 0xD4EF3085);
			b = hh(b, c, d, a, x[i + 6], 23, 0x04881D05);
			a = hh(a, b, c, d, x[i + 9], 4, 0xD9D4D039);
			d = hh(d, a, b, c, x[i + 12], 11, 0xE6DB99E5);
			c = hh(c, d, a, b, x[i + 15], 16, 0x1FA27CF8);
			b = hh(b, c, d, a, x[i + 2], 23, 0xC4AC5665);

			a = ii(a, b, c, d, x[i + 0], 6, 0xF4292244);
			d = ii(d, a, b, c, x[i + 7], 10, 0x432AFF97);
			c = ii(c, d, a, b, x[i + 14], 15, 0xAB9423A7);
			b = ii(b, c, d, a, x[i + 5], 21, 0xFC93A039);
			a = ii(a, b, c, d, x[i + 12], 6, 0x655B59C3);
			d = ii(d, a, b, c, x[i + 3], 10, 0x8F0CCC92);
			c = ii(c, d, a, b, x[i + 10], 15, 0xFFEFF47D);
			b = ii(b, c, d, a, x[i + 1], 21, 0x85845DD1);
			a = ii(a, b, c, d, x[i + 8], 6, 0x6FA87E4F);
			d = ii(d, a, b, c, x[i + 15], 10, 0xFE2CE6E0);
			c = ii(c, d, a, b, x[i + 6], 15, 0xA3014314);
			b = ii(b, c, d, a, x[i + 13], 21, 0x4E0811A1);
			a = ii(a, b, c, d, x[i + 4], 6, 0xF7537E82);
			d = ii(d, a, b, c, x[i + 11], 10, 0xBD3AF235);
			c = ii(c, d, a, b, x[i + 2], 15, 0x2AD7D2BB);
			b = ii(b, c, d, a, x[i + 9], 21, 0xEB86D391);

			a = add(a, olda);
			b = add(b, oldb);
			c = add(c, oldc);
			d = add(d, oldd);
		}
		return rhex(a) + rhex(b) + rhex(c) + rhex(d);
	}
	public static void main(String[] args){
		MD5 t = new MD5();
//		System.out.println(t.calcMD5("wangmingjie"));
		//2a776946fb6a617955d961b4dfefa9c8
		//2a776946fb6a617955d961b4dfefa9c8
		System.out.println(t.calcMD5("1"));
		//c4ca4238a0b923820dcc509a6f75849b
		//c4ca4238a0b923820dcc509a6f75849b
		System.out.println(t.calcMD5("中国"));
		//4c9370f4ddb0ff4862701ee019a58b46
	}
}