Australian Personal Computer 2000 November/APCD25112k.iso/feature/webserv/SAMBAR43.ZIP/_SETUP.1/javaeng.jar/com/sambar/javaeng/SambarUtils.java

Java Source | 2000-04-03 | 7.3 KB | 259 lines

/*
**         Sambar Server JAVA Engine Implementation
**
**        Confidential Property of Tod Sambar
**        (c) Copyright Tod Sambar 1999
**        All rights reserved.
*/
package com.sambar.javaeng;

import java.net.URLEncoder;
import java.util.Date;
import java.util.Vector;
import java.util.StringTokenizer;
import java.util.Locale;
import java.util.TimeZone;
import java.util.NoSuchElementException;
import java.text.SimpleDateFormat;
import javax.servlet.http.Cookie;

public final class SambarUtils
{
    public final static String URLEncode(String str)
    {
        if (str == null)
            return null;
        return URLEncoder.encode(str);
    }

    /*
    ** This method decodes the given urlencoded string.
    **
    ** @param  str the url-encoded string
    ** @return the decoded string
    ** @exception IllegalArgumentException If a '%' is not
    ** followed by a valid 2-digit hex number.
    */
    public final static String URLDecode(String str)
        throws IllegalArgumentException
    {
        if (str == null)
            return  null;

        StringBuffer dec = new StringBuffer();    // decoded string output
        int strPos = 0;
        int strLen = str.length();

        dec.ensureCapacity(str.length());
        while (strPos < strLen)
        {
            int laPos;        // lookahead position

            // look ahead to next URLencoded metacharacter, if any
            for (laPos = strPos; laPos < strLen; laPos++)
            {
                char laChar = str.charAt(laPos);
                if ((laChar == '+') || (laChar == '%'))
                    break;
            }

            // if there were non-metacharacters, copy them all as a block
            if (laPos > strPos)
            {
                dec.append(str.substring(strPos,laPos));
                strPos = laPos;
            }

            // shortcut out of here if we're at the end of the string
            if (strPos >= strLen)
                break;

            // process next metacharacter
            char metaChar = str.charAt(strPos);
            if (metaChar == '+')
            {
                dec.append(' ');
                strPos++;
                continue;
            }
            else if (metaChar == '%')
            {
                try
                {
                    dec.append((char)Integer.parseInt(str.substring(strPos + 1,
                        strPos + 3), 16));
                }
                catch (NumberFormatException e)
                {
                    throw new IllegalArgumentException("invalid hexadecimal "
                        + str.substring(strPos + 1, strPos + 3)
                        + " in URLencoded string (illegal unescaped '%'?)" );
                }
                catch (StringIndexOutOfBoundsException e)
                {
                    throw new IllegalArgumentException("illegal unescaped '%' "
                        + " in URLencoded string" );
                }
                strPos += 3;
            }
        }

        return dec.toString();
    }

    /*
    ** Parse a cookie header into an array of cookies as per
    ** RFC2109 - HTTP Cookies
    **
    ** @param cookieHdr The Cookie header value.
    */
    public static Cookie[] parseCookies(String cookieHdr)
    {
        Vector cookieJar = new Vector();

        if(cookieHdr == null || cookieHdr.length() == 0)
            return new Cookie[0];

        StringTokenizer stok = new StringTokenizer(cookieHdr, "; ");
        while (stok.hasMoreTokens())
        {
            try
            {
                String tok = stok.nextToken();
                int equals_pos = tok.indexOf('=');
                if (equals_pos > 0)
                {
                    String name = URLDecode(tok.substring(0, equals_pos));
                    String value = URLDecode(tok.substring(equals_pos + 1));
                    cookieJar.addElement(new Cookie(name, value));
                }
                else if ( tok.length() > 0 && equals_pos == -1 )
                {
                    String name = URLDecode(tok);
                    cookieJar.addElement(new Cookie(name, ""));
                }
            }
            catch (IllegalArgumentException badcookie)
            {
            }
            catch (NoSuchElementException badcookie)
            {
            }
        }

        Cookie[] cookies = new Cookie[cookieJar.size()];
        cookieJar.copyInto(cookies);
        return cookies;
    }

    private static SimpleDateFormat cookieDate =
        new SimpleDateFormat("EEE, dd-MMM-yyyy HH:mm:ss zz", Locale.US );

    static
    {
        cookieDate.setTimeZone(TimeZone.getTimeZone("GMT"));
    }

    /*
    ** Encode a cookie as per the Netscape Cookies specification. The
    ** resulting string can be used in a Set-Cookie header.
    **
    ** @param cookie The cookie to encode.
    ** @return A string following Netscape Cookies specification.
    */
    public static String encodeCookie(Cookie cookie)
    {
        StringBuffer buf = new StringBuffer( cookie.getName() );
        buf.append('=');
        buf.append(cookie.getValue());

        long age = cookie.getMaxAge();
        if (age > 0)
        {
            buf.append("; expires=");
            buf.append(cookieDate.format(
                new Date(System.currentTimeMillis() + (long)age * 1000 )));
        }
        else if (age == 0)
        {
            buf.append("; expires=");
            // Set expiration to the epoch to delete the cookie
            buf.append(cookieDate.format(new Date(0)));
        }

        if (cookie.getDomain() != null)
        {
            buf.append("; domain=");
            buf.append(cookie.getDomain());
        }

        if (cookie.getPath() != null)
        {
            buf.append("; path=");
            buf.append(cookie.getPath());
        }

        if (cookie.getSecure())
            buf.append("; secure");

        return buf.toString();
    }

    /*
    ** Parse a content-type header for the character encoding. If the
    ** content-type is null or there is no explicit character encoding,
    ** ISO-8859-1 is returned.
    **
    ** @param contentType a content type header.
    */
    public static String parseCharacterEncoding(String contentType)
    {
        int start;
        int end;

        if ((contentType == null) ||
            ((start = contentType.indexOf("charset="))) == -1 )
        {
            return "ISO-8859-1";
        }

        String encoding = contentType.substring(start + 8);

        if ((end = encoding.indexOf(";")) > -1)
            return encoding.substring(0, end);
        else
            return encoding;
    }

    /*
    ** Concatenate 2 paths, dealing with ..
    ** ( /a/b/c + d = /a/b/d, /a/b/c + ../d = /a/d )
    */
    public static String catPath(String lookupPath, String path)
    {
        // Cut off the last slash and everything beyond
        int index = lookupPath.lastIndexOf("/");
        lookupPath = lookupPath.substring(0, index);

        // Deal with .. by chopping dirs off the lookup path
        while (path.startsWith("../"))
        {
            if (lookupPath.length() > 0)
            {
                index = lookupPath.lastIndexOf("/");
                lookupPath = lookupPath.substring(0, index);
            }
            else
            {
                // More ..'s than dirs, return null
                return null;
            }

            index = path.indexOf("../") + 3;
            path = path.substring(index);
        }

        return lookupPath + "/" + path;
    }
}