短链的简单处理

来源：互联网发布：网络在线麻将编辑：程序博客网时间：2024/06/05 02:12

短网址

package com.csdn.shorturl;

public class ShortUrlGenerator {

/**

* @param args

public static void main(String[] args) {

// 长连接： http://tech.sina.com.cn/i/2011-03-23/11285321288.shtml

// 新浪解析后的短链接为： http://t.cn/h1jGSC

String sLongUrl = "http://tech.sina.com.cn/i/2011-03-23/11285321288.shtml" ; // 3BD768E58042156E54626860E241E999

String[] aResult = shortUrl (sLongUrl);

// 打印出结果

for ( int i = 0; i < aResult. length ; i++) {

System. out .println( "[" + i + "]:::" + aResult[i]);

}

public static String[] shortUrl(String url) {

// 可以自定义生成 MD5 加密字符传前的混合 KEY

String key = "wuguowei" ;

// 要使用生成 URL 的字符

String[] chars = new String[] { "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" , "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"

};

// 对传入网址进行 MD5 加密

String sMD5EncryptResult = ( new CMyEncrypt()).getMD5OfStr(key + url);

String hex = sMD5EncryptResult;

String[] resUrl = new String[4];

for ( int i = 0; i < 4; i++) {

// 把加密字符按照 8 位一组 16 进制与 0x3FFFFFFF 进行位与运算

String sTempSubString = hex.substring(i * 8, i * 8 + 8);

// 这里需要使用 long 型来转换，因为 Inteper .parseInt() 只能处理 31 位 , 首位为符号位 , 如果不用 long ，则会越界

long lHexLong = 0x3FFFFFFF & Long.parseLong (sTempSubString, 16);

String outChars = "" ;

for ( int j = 0; j < 6; j++) {

// 把得到的值与 0x0000003D 进行位与运算，取得字符数组 chars 索引

long index = 0x0000003D & lHexLong;

// 把取得的字符相加

outChars += chars[( int ) index];

// 每次循环按位右移 5 位

lHexLong = lHexLong >> 5;

}

// 把字符串存入对应索引的输出数组

resUrl[i] = outChars;

}

return resUrl;

}

跳转原理

当我们生成短链接之后，只需要在表中（数据库或者NoSql ）存储原始链接与短链接的映射关系即可。当我们访问短链接时，只需要从映射关系中找到原始链接，即可跳转到原始链接。

==========================

View Code

package com.youngsun.lbt;

publicclass ShortUrlGenerator {
publicstaticvoid main(String[] args) {
// 长连接： http://www.young-sun.com
// 新浪解析后的短链接为： http://***/Nvqqem
String sLongUrl = "http://www.young-sun.com" ; // 3BD768E58042156E54626860E241E999
String[] aResult = shortUrl (sLongUrl);
// 打印出结果
for ( int i = 0; i < aResult. length ; i++) {
System. out .println( "The string [" + i + "] is " + aResult[i]);
}
}
publicstatic String[] shortUrl(String url) {
// 可以自定义生成 MD5 加密字符传前的混合 KEY
String key = "libotao" ;
// 要使用生成 URL 的字符
String[] chars = new String[] { "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" , "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"
};
// 对传入网址进行 MD5 加密
String sMD5EncryptResult = (Encript.md5(key + url));
String hex = sMD5EncryptResult;
String[] resUrl = new String[4];
//得到 4组短链接字符串
for ( int i = 0; i < 4; i++) {
// 把加密字符按照 8 位一组 16 进制与 0x3FFFFFFF 进行位与运算
String sTempSubString = hex.substring(i * 8, i * 8 + 8);
// 这里需要使用 long 型来转换，因为 Inteper .parseInt() 只能处理 31 位 , 首位为符号位 , 如果不用 long ，则会越界
long lHexLong = 0x3FFFFFFF & Long.parseLong (sTempSubString, 16);
String outChars = "" ;
//循环获得每组6位的字符串
for ( int j = 0; j < 6; j++) {
// 把得到的值与 0x0000003D 进行位与运算，取得字符数组 chars 索引
//(具体需要看chars数组的长度以防下标溢出，注意起点为0)
long index = 0x0000003D & lHexLong;
// 把取得的字符相加
outChars += chars[( int ) index];
// 每次循环按位右移 5 位
lHexLong = lHexLong >> 5;
}
// 把字符串存入对应索引的输出数组
resUrl[i] = outChars;
}
return resUrl;
}

}

输出结果：

The string [0] is ZBbINb

The string [1] is VBnqMb

The string [2] is Nvqqem

The string [3] is yiQFja

==============c#

public static string[] ShortUrl(string url)
        {
            //可以自定义生成MD5加密字符传前的混合KEY
            string key = "Leejor";
            //要使用生成URL的字符
            string[] chars = new string[]{
                "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","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"

              };
            //对传入网址进行MD5加密
            string hex = System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(key + url, "md5");

            string[] resUrl = new string[4];

            for (int i = 0; i < 4; i++)
            {
                //把加密字符按照8位一组16进制与0x3FFFFFFF进行位与运算
                int hexint = 0x3FFFFFFF & Convert.ToInt32("0x" + hex.Substring(i * 8, 8), 16);
                string outChars = string.Empty;
                for (int j = 0; j < 6; j++)
                {
                    //把得到的值与0x0000003D进行位与运算，取得字符数组chars索引
                    int index = 0x0000003D & hexint;
                    //把取得的字符相加
                    outChars += chars[index];
                    //每次循环按位右移5位
                    hexint = hexint >> 5;
                }
                //把字符串存入对应索引的输出数组
                resUrl[i] = outChars;
            }

            return resUrl;
        }

现在可以直接使用该方法，可以等到下面四组值

ShortUrl(http://www.me3.cn)[0]; //得到值fAVfui

ShortUrl(http://www.me3.cn)[1]; //得到值3ayQry

ShortUrl(http://www.me3.cn)[2]; //得到值UZzyUr

ShortUrl(http://www.me3.cn)[3]; //得到值36rQZn