長いurlを短いurlに変換
1967 ワード
public class ShortAddressUtil {
private static final char[] HEX_16;
private static final char[] HEX_62;
private static MessageDigest digest;
static{
HEX_16 = new char[]{'0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f'};
HEX_62 = new char[62];
int index = 0;
for(int i = 'a'; i<'a'+26; i++,index++){
HEX_62[index] = (char)i;
}
for(int i = '0'; i<'0'+10; i++,index++){
HEX_62[index] = (char)i;
}
for(int i = 'A'; i<'A'+26; i++,index++){
HEX_62[index] = (char)i;
}
try {
digest = MessageDigest.getInstance("MD5");
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
}
}
public static String[] convertShortURL(String longURL){
if(digest == null) return null;
digest.update(longURL.getBytes());
byte[] bs = digest.digest();
char[] buff = new char[ bs.length * 2 ];
for(int i=0;i<bs.length;i++){
buff[i*2] = HEX_16[bs[i]>>>4&0xF];
buff[i*2+1] = HEX_16[bs[i]&0xF];
}
String[] resURL = new String[4];
for(int i=0;i<4;i++){
int int16 = (int) (0x3fffffff & Long.parseLong(new String(buff,i*8,8),16));
char[] chs = new char[6];
for(int j=0;j<6;j++){
chs[j] = HEX_62[int16 & 0x3d];
int16 = int16>>>5;
}
resURL[i] = new String(chs);
}
return resURL;
}
public static void main(String[] args) {
System.out.println(Arrays.toString(convertShortURL("http://www.hao123.com/index.html?debug=true")));
}
}