原理:

新浪微博的URL都是如:http://weibo.com/2480531040/z8ElgBLeQ这样三部分.

第一部分(绿色部分)为新浪微博的域名,第二部分(红色部分)为博主Uid,第三部分(蓝色)为一串貌似随机的字符串.

如果通过方法能计算出蓝色字串与返回的数组里的对应关系则好解决多了.

首先分组蓝色字串 ,从后往前4个字符一组，得到以下三组字符：
z
8Elg
BLeQ

将它们分别转换成62进制的数值则为 35, 2061702, 8999724  将它们组合起来就是一串 3520617028999724 类似这样的字串

通过发现返回的二维数组里有个 [mid]的字段,其返回结果为 3520617028999724.刚好是对应的.

http://weibo.com/aj/v6/mblog/info/big?ajwvr=6&id=3919740416635598&page=1

package step0;


/**
 * 
    * @ClassName: Mid2IdUtil Java版
    * @Description:  新浪uid转url (id转mid)
    * @author zeze
    * @date 2016年4月10日 上午10:49:40 
    *
 */
public class Id2MidUtil {
    public static void main(String[] args) {
        System.out.println(Uid2Mid("Aw8Wrzaes"));
        System.out.println(Mid2Uid("3676608718380816"));//Mid2Id
    }
    private static String[] str62keys = { "0", "1", "2", "3", "4", "5", "6",
            "7", "8", "9", "a", "b", "c", "d", "e", "f", "g", "h", "i", "j",
            "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w",
            "x", "y", "z", "A", "B", "C", "D", "E", "F", "G", "H", "I", "J",
            "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W",
            "X", "Y", "Z" };

    public static String IntToEnode62(Integer int10) {
        String s62 = "";
        int r = 0;
        while (int10 != 0) {
            r = int10 % 62;
            s62 = str62keys[r] + s62;
            int10 = (int) Math.floor(int10 / 62.0);
        }
        return s62;
    }
    
     //62进制转成10进制
    public static String Str62toInt(String str62)
    {
        long i64 = 0;
        for (int i = 0; i < str62.length(); i++)
        {
            long Vi = (long)Math.pow(62, (str62.length() - i - 1));
            String t = str62.substring(i,i+1);
           
            i64 += Vi * findindex(t);
        }
       // System.out.println(i64);
        return Long.toString(i64);
    }
    
    public static int findindex(String t)
    {
        int index=0;
        for(int i=0;i<str62keys.length;i++)
        {
            if(str62keys[i].equals(t)){
                index=i;
                break;
            }
        }
        return index;
    }
 
     public static String Uid2Mid(String mid)
        {
            String id = "";
            for (int i = mid.length() - 4; i > -4; i = i - 4) //从最后往前以4字节为一组读取URL字符
            {
                int offset1 = i < 0 ? 0 : i;
                int len = i < 0 ? mid.length() % 4 : 4;
                
                String str = mid.substring(offset1, offset1+len);
               // System.out.println(offset1+" "+len+" "+str);
                
                str = Str62toInt(str);
                
                if (offset1 > 0) //若不是第一组，则不足7位补0
                {
                    while (str.length() < 7)
                    {
                        str = "0" + str;
                    }
                }
                id = str + id;
            }

            return id;
        }
    
    
    public static String Mid2Uid(String str10) {
        String mid = "";
        int count = 1 ;
        for (int i = str10.length() - 7; i > -7; i = i - 7) // 从最后往前以7字节为一组读取字符
        {
            int offset = i < 0 ? 0 : i;
            int len = i < 0 ? str10.length() % 7 : 7;
            String temp = str10.substring(offset, offset + len);
            String url =IntToEnode62(Integer.valueOf(temp));
            if(count!=3){//z xghm uXym 生成的链接从右往左的前2组，4位一组，不足4位的补0
                for(int j=0;j<4-url.length();j++){
                    url = "0"+url;
                }
            }
            mid = url+mid;                       
                      count++;
               }
        return mid;
    }
}