MD5加密中文字符问题详解

MD5加密中文字符串结果不一致时，通常是由于md5加密时未使用编码造成的。如"MD5加密字符串".getBytes(“utf-8”)进行设置编码。详情请参考以下代码：

package com.pbh.util;
import java.security.MessageDigest;
public class Md5Utils {
 /***
	 * MD5加码 生成32位md5码
	 */
	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();

	}
	/***
	 * MD5加码(字符中含有中文时) 生成32位小写md5码
	 */
	public final static String md5zw(String inStr) {
		char hexDigits[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
				'a', 'b', 'c', 'd', 'e', 'f','g','h'};
		try {
			byte[] strTemp = s.getBytes("utf-8");//中文加密需要设置utf-8编码
			MessageDigest mdTemp = MessageDigest.getInstance("MD5");
			mdTemp.update(strTemp);
			byte[] md = mdTemp.digest();
			int j = md.length;
			char str[] = new char[j * 2];
			int k = 0;
			for (int i = 0; i < j; i++) {
				byte b = md[i];
				//System.out.println((int)b);
				str[k++] = hexDigits[b >> 4 & 0xf];
				str[k++] = hexDigits[b & 0xf];
			}
			return new String(str);
		} catch (Exception e) {return null;}
	}
	/**
	 * 加密解密算法 执行一次加密，两次解密
	 */ 
	public static String convertMD5(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;
	}
	public static String decryptMD5(String inStr){
		return null;
	}
}