Java中md5加密

方法一、

public final static String md5(String s) {
        char hexDigits[] = {\'0\',\'1\',\'2\',\'3\',\'4\',\'5\',\'6\',\'7\',\'8\',\'9\',\'a\',\'b\',\'c\',\'d\',\'e\',\'f\'};
        try {
            byte[] strTemp = s.getBytes();
            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 byte0 = md[i];
                str[k++] = hexDigits[byte0 >>> 4 & 0xf];
                str[k++] = hexDigits[byte0 & 0xf];
            }
            return new String(str).toUpperCase();
        } catch (Exception e) {
            return null;
        }
    }

方法二，直接使用apache提供的工具类

import org.apache.commons.codec.digest;

public static String encryptMD5(String str) {
        return DigestUtils.md5Hex(str);
    }