Class Util


  • public class Util
    extends Object
    This class holds various utility methods.
    Version:
    0.3-3 06/05/2001
    Author:
    Ronald Tschal���r
    • Method Detail

      • dequoteString

        public static final String dequoteString​(String str)
        Replace quoted characters by their unquoted version. Quoted characters are characters preceded by a slash. E.g. "\c" would be replaced by "c". This is used in parsing http headers where quoted-characters are allowed in quoted-strings and often used to quote the quote character <">.
        Parameters:
        str - the string do dequote
        Returns:
        the string do with all quoted characters replaced by their true value.
      • quoteString

        public static final String quoteString​(String str,
                                               String qlist)
        Replace given characters by their quoted version. Quoted characters are characters preceded by a slash. E.g. "c" would be replaced by "\c". This is used in generating http headers where certain characters need to be quoted, such as the quote character <">.
        Parameters:
        str - the string do quote
        qlist - the list of characters to quote
        Returns:
        the string do with all characters replaced by their quoted version.
      • parseHeader

        public static final Vector parseHeader​(String header)
                                        throws ParseException
        This parses the value part of a header. All quoted strings are dequoted.
        Parameters:
        header - the value part of the header.
        Returns:
        a Vector containing all the elements; each entry is an instance of HttpHeaderElement.
        Throws:
        ParseException - if the syntax rules are violated.
        See Also:
        parseHeader(java.lang.String, boolean)
      • parseHeader

        public static final Vector parseHeader​(String header,
                                               boolean dequote)
                                        throws ParseException
        This parses the value part of a header. The result is a Vector of HttpHeaderElement's. The syntax the header must conform to is:
         header  = [ element ] *( "," [ element ] )
         element = name [ "=" [ value ] ] *( ";" [ param ] )
         param   = name [ "=" [ value ] ]
         
         name    = token
         value   = ( token | quoted-string )
         
         token         = 1*<any char except "=", ",", ";", <"> and
                               white space>
         quoted-string = <"> *( text | quoted-char ) <">
         text          = any char except <">
         quoted-char   = "\" char
         
        Any amount of white space is allowed between any part of the header, element or param and is ignored. A missing value in any element or param will be stored as the empty string; if the "=" is also missing null will be stored instead.
        Parameters:
        header - the value part of the header.
        dequote - if true all quoted strings are dequoted.
        Returns:
        a Vector containing all the elements; each entry is an instance of HttpHeaderElement.
        Throws:
        ParseException - if the above syntax rules are violated.
        See Also:
        HttpHeaderElement
      • hasToken

        public static final boolean hasToken​(String header,
                                             String token)
                                      throws ParseException
        Determines if the given header contains a certain token. The header must conform to the rules outlined in parseHeader().
        Parameters:
        header - the header value.
        token - the token to find; the match is case-insensitive.
        Returns:
        true if the token is present, false otherwise.
        Throws:
        ParseException - if this is thrown parseHeader().
        See Also:
        parseHeader(java.lang.String)
      • getElement

        public static final HttpHeaderElement getElement​(Vector header,
                                                         String name)
        Get the HttpHeaderElement with the name name.
        Parameters:
        header - a vector of HttpHeaderElement's, such as is returned from parseHeader()
        name - the name of element to retrieve; matching is case-insensitive
        Returns:
        the request element, or null if none found.
        See Also:
        parseHeader(java.lang.String)
      • getParameter

        public static final String getParameter​(String param,
                                                String hdr)
                                         throws ParseException
        retrieves the value associated with the parameter param in a given header string. It parses the header using parseHeader() and then searches the first element for the given parameter. This is used especially in headers like 'Content-type' and 'Content-Disposition'.

        quoted characters ("\x") in a quoted string are dequoted.

        Parameters:
        param - the parameter name
        hdr - the header value
        Returns:
        the value for this parameter, or null if not found.
        Throws:
        ParseException - if the above syntax rules are violated.
        See Also:
        parseHeader(java.lang.String)
      • assembleHeader

        public static final String assembleHeader​(Vector pheader)
        Assembles a Vector of HttpHeaderElements into a full header string. The individual header elements are seperated by a ", ".
        Parameters:
        pheader - the parsed header
        Returns:
        a string containing the assembled header
      • sameHttpURL

        public static final boolean sameHttpURL​(URL url1,
                                                URL url2)
        Compares two http urls for equality. This exists because the method java.net.URL.sameFile() is broken (an explicit port 80 doesn't compare equal to an implicit port, and it doesn't take escapes into account).

        Two http urls are considered equal if they have the same protocol (case-insensitive match), the same host (case-insensitive), the same port and the same file (after decoding escaped characters).

        Parameters:
        url1 - the first url
        url1 - the second url
        Returns:
        true if url1 and url2 compare equal
      • defaultPort

        public static final int defaultPort​(String protocol)
        Deprecated.
        use URI.defaultPort() instead
        Return the default port used by a given protocol.
        Parameters:
        protocol - the protocol
        Returns:
        the port number, or 0 if unknown
        See Also:
        URI.defaultPort(java.lang.String)
      • httpDate

        public static final String httpDate​(Date date)
        This returns a string containing the date and time in date formatted according to a subset of RFC-1123. The format is defined in the HTTP/1.0 spec (RFC-1945), section 3.3, and the HTTP/1.1 spec (RFC-2616), section 3.3.1. Note that Date.toGMTString() is close, but is missing the weekday and supresses the leading zero if the day is less than the 10th. Instead we use the SimpleDateFormat class.

        Some versions of JDK 1.1.x are bugged in that their GMT uses daylight savings time... Therefore we use our own timezone definitions.

        Parameters:
        date - the date and time to be converted
        Returns:
        a string containg the date and time as used in http
      • getPath

        public static final String getPath​(String resource)
        Extract the path from an http resource.

        The "resource" part of an HTTP URI can contain a number of parts, some of which are not always of interest. These methods here will extract the various parts, assuming the following syntanx (taken from RFC-2616):

         resource = [ "/" ] [ path ] [ ";" params ] [ "?" query ] [ "#" fragment ]
         
        Parameters:
        resource - the resource to split
        Returns:
        the path, including any leading "/"
        See Also:
        getParams(java.lang.String), getQuery(java.lang.String), getFragment(java.lang.String)
      • getParams

        public static final String getParams​(String resource)
        Extract the params part from an http resource.
        Parameters:
        resource - the resource to split
        Returns:
        the params, or null if there are none
        See Also:
        getPath(java.lang.String)
      • getQuery

        public static final String getQuery​(String resource)
        Extract the query string from an http resource.
        Parameters:
        resource - the resource to split
        Returns:
        the query, or null if there was none
        See Also:
        getPath(java.lang.String)
      • getFragment

        public static final String getFragment​(String resource)
        Extract the fragment part from an http resource.
        Parameters:
        resource - the resource to split
        Returns:
        the fragment, or null if there was none
        See Also:
        getPath(java.lang.String)
      • wildcardMatch

        public static final boolean wildcardMatch​(String pattern,
                                                  String name)
        Match pattern against name, where pattern may contain wildcards ('*').
        Parameters:
        pattern - the pattern to match; may contain '*' which match any number (0 or more) of any character (think file globbing)
        name - the name to match against the pattern
        Returns:
        true if the name matches the pattern; false otherwise