在jsp中作HTTP认证的方法

    迩来接洽了jsp中作http认证的题目，它的处事办法如次：

1、server发送一个诉求认证代码401和一个儿消息www-authenticate，激励browser弹出一个认证窗口

2、server博得browser送来的认证头"authorization",它是加密的了，要用base64本领解密，博得明文的用户名和暗号

3、查看用户名和暗号，按照截止传递各别的页面

以次是jsp的片断，你也不妨把它做出include文献。和base64的加解密的class源码。 如有爱好可与我接洽：unixboy@yeah.net

<jsp:usebean id="base64"scope="page"class="base64"/> <% if(request.getheader("authorization")==null){    response.setstatus(401);    response.setheader("www-authenticate","basic realm=\"unixboy.com\""); }else{    string encoded=(request.getheader("authorization"));    string tmp=encoded.substring(6);    string up=base64.decode(tmp);    string user="";    string password="";    if(up!=null){         user=up.substring(0,up.indexof(":"));     password=up.substring(up.indexof(":")+1);    }    if(user.equals("unixboy")&&password.equals("123456")){         //认证胜利    }else{         //认证波折    } } %>

//动静加解密class public class base64 {         /** decode a base 64 encoded string.           *<p><h4>string to byte conversion</h4>           * this method uses a naive string to byte interpretation, it simply gets each           * char of the string and calls it a byte.</p>           *<p>since we should be dealing with base64 encoded strings that is a reasonable           * assumption.</p>           *<p><h4>end of data</h4>           * we don''t try to stop the converion when we find the"="end of data padding char.           * we simply add zero bytes to the unencode buffer.</p>         */         public static string decode(string encoded)         {                 stringbuffer sb=new stringbuffer();                 int maxturns;                 //work out how long to loop for.                 if(encoded.length()%3==0)                 maxturns=encoded.length();                 else                 maxturns=encoded.length()+(3-(encoded.length()%3));                 //tells us whether to include the char in the unencode                 boolean skip;                 //the unencode buffer                 byte[] unenc=new byte[4];                 byte b;                 for(int i=0,j=0;i<maxturns;i++)                 {                         skip=false;                         //get the byte to convert or 0                         if(i<encoded.length())                         b=(byte)encoded.charat(i);                         else                         b=0;                         //test and convert first capital letters, lowercase, digits then ''+'' and ''/''                         if(b>=65&&b<91)                         unenc[j]=(byte)(b-65);                         else if(b>=97&&b<123)                         unenc[j]=(byte)(b-71);                         else if(b>=48&&b<58)                         unenc[j]=(byte)(b+4);                         else if(b==''+'')                         unenc[j]=62;                         else if(b==''/'')                         unenc[j]=63;                         //if we find"="then data has finished, we''re not really dealing with this now                         else if(b==''='')                         unenc[j]=0;                         else                         {                                 char c=(char)b;                                 if(c==''\n'' || c==''\r'' || c=='' '' || c==''\t'')                                 skip=true;                                 else                                 //could throw an exception here? it''s input we don''t understand.                                 ;                         }                         //once the array has boiled convert the bytes back into chars                         if(!skip&&++j==4)                         {                                 //shift the 6 bit bytes into a single 4 octet word                                 int res=(unenc[0]<<18)+(unenc[1]<<12)+(unenc[2]<<6)+unenc[3];                                 byte c;                                 int k=16;                                 //shift each octet down to read it as char and add to stringbuffer                                 while(k>=0)                                 {                                         c=(byte)(res>>k);                                         if ( c>0 )                                         sb.append((char)c);                                         k-=8;                                 }                                 //reset j and the unencode buffer                                 j=0;                                 unenc[0]=0;unenc[1]=0;unenc[2]=0;unenc[3]=0;                         }                 }                 return sb.tostring();         }                  /** encode plaintext data to a base 64 string           * @param plain the text to convert. if plain is longer than 76 characters this method           *             returns null (see rfc2045).           * @return the encoded text (or null if string was longer than 76 chars).         */         public static string encode(string plain)         {                 if(plain.length()>76)                 return null;                 int maxturns;                 stringbuffer sb=new stringbuffer();                 //the encode buffer                 byte[] enc=new byte[3];                 boolean end=false;                 for(int i=0,j=0;!end;i++)                 {                         char _ch=plain.charat(i);                         if(i==plain.length()-1)                         end=true;                         enc[j++]=(byte)plain.charat(i);                         if(j==3 || end)                         {                                 int res;                                 //this is a bit inefficient at the end point                                 //worth it for the small decrease in code size?                                 res=(enc[0]<<16)+(enc[1]<<8)+enc[2];                                 int b;                                 int lowestbit=18-(j*6);                                 for(int toshift=18;toshift>=lowestbit;toshift-=6)                                 {                                         b=res>>>toshift;                                         b&=63;                                         if(b>=0&&b<26)                                         sb.append((char)(b+65));                                         if(b>=26&&b<52)                                         sb.append((char)(b+71));                                         if(b>=52&&b<62)                                         sb.append((char)(b-4));                                         if(b==62)                                         sb.append(''+'');                                         if(b==63)                                         sb.append(''/'');                                         if(sb.length()%76==0)                                         sb.append(''\n'');                                 }                                 //now set the end chars to be pad character if there                                 //was less than integral input (ie: less than 24 bits)                                 if(end)                                 {                                         if(j==1)                                         sb.append("==");                                         if(j==2)                                         sb.append(''='');                                 }                                 enc[0]=0;enc[1]=0;enc[2]=0;                                 j=0;                         }                 }                 return sb.tostring();         } }