Module iu.util
Package edu.iu

Class IuWebUtils

java.lang.Object
edu.iu.IuWebUtils
public final class IuWebUtils extends Object
Provides useful utility methods for low-level web client and server interactions.

  • Method Details

    • vchar

      static boolean vchar(char c)
      VCHAR = %x21-7E
      Parameters:
      c - character
      Returns:
      true if c matches VCHAR ABNF rule; else false
      See Also:

    • alpha

      static boolean alpha(char c)
      ALPHA = %x41-5A / %x61-7A
      Parameters:
      c - character
      Returns:
      true if c matches ALHPA ABNF rule; else false
      See Also:

    • digit

      static boolean digit(char c)
      DIGIT = %x30-39
      Parameters:
      c - character
      Returns:
      true if c matches DIGIT ABNF rule; else false
      See Also:

    • ctext

      static boolean ctext(char c)
      ctext = HTAB / SP / %x21-27 / %x2A-5B / %x5D-7E / obs-text
      Parameters:
      c - character
      Returns:
      true if c matches ctext ABNF rule; else false
      See Also:

    • obsText

      static boolean obsText(char c)
      obs-text = %x80-FF
      Parameters:
      c - character
      Returns:
      true if c matches obs-text ABNF rule; else false
      See Also:

    • comment

      static int comment(String s, int pos)
      comment = "(" *( ctext / quoted-pair / comment ) ")"
      Parameters:
      s - input string
      pos - position at start of comment
      Returns:
      end position after matching comment ABNF rule; returns pos if token68 was not matched
      See Also:

    • token68

      static int token68(String s, int pos)
      token68 = 1*( ALPHA / DIGIT / "-" / "." / "_" / "~" / "+" / "/" ) *"="
      Parameters:
      s - input string
      pos - position at start of token68 character
      Returns:
      end position after matching token68 ABNF rule; returns pos if token68 was not matched
      See Also:

    • tchar

      static boolean tchar(char c)
      tchar = "!" / "#" / "$" / "%" / "&" / "'" / "*" / "+" / "-" / "." / "^" / "_" / "`" / "|" / "~" / DIGIT / ALPHA
      Parameters:
      c - character
      Returns:
      true if c matches obs-text ABNF rule; else false
      See Also:

    • token

      static int token(String s, int pos)
      token = 1*tchar
      Parameters:
      s - input string
      pos - position at start of token character
      Returns:
      end position of a matching token ABNF rule; returns pos if token was not matched
      See Also:

    • bws

      static int bws(String s, int pos)
      BWS = OWS

      OWS = *( SP / HTAB )

      RWS = 1*( SP / HTAB )

      Parameters:
      s - input string
      pos - position at start of token character
      Returns:
      end position of a matching BWS ABNF rule
      See Also:

    • sp

      static int sp(String s, int pos)
      1*SP
      Parameters:
      s - input string
      pos - position at start of token character
      Returns:
      end position of a matching sp ABNF rule
      See Also:

    • product

      static int product(String s, int pos)
      product = token [ "/" product-version ]

      product-version = token

      Parameters:
      s - input string
      pos - position at start of product expression
      Returns:
      end position of a matching product ABNF rule; pos if not matched

    • qdtext

      static boolean qdtext(char c)
      qdtext = HTAB / SP / "!" / %x23-5B / %x5D-7E / obs-text
      Parameters:
      c - character
      Returns:
      true if c matches qdtext ABNF rule; else false
      See Also:

    • quotedPair

      static int quotedPair(String s, int pos)
      quoted-pair = "\" ( HTAB / SP / VCHAR / obs-text )
      Parameters:
      s - input string
      pos - position at start of token character
      Returns:
      end position of a matching quoted-pair ABNF rule; pos if the rule was not matched
      See Also:

    • quotedString

      static int quotedString(String s, int start)
      quoted-string = DQUOTE *( qdtext / quoted-pair ) DQUOTE
      Parameters:
      s - input string
      start - position at start of token character
      Returns:
      end position of a matching BWS ABNF rule
      See Also:

    • isVisibleAscii

      public static boolean isVisibleAscii(String s, int minLength)
      Determines whether or not a string is composed entirely of non-whitespace visible ASCII characters, and at least minLength characters, but no longer than 1024.
      Parameters:
      s - string to check
      minLength - minimum length
      Returns:
      true if all characters are visible ASCII

    • isRootOf

      public static boolean isRootOf(URI rootUri, URI resourceUri)
      Determines if a root URI encompasses a resource URI.
      Parameters:
      rootUri - root URI
      resourceUri - resource URI
      Returns:
      URI

    • createChallenge

      public static String createChallenge(String scheme, Map<String,String> params)
      Creates an authentication challenge sending to a client via the WWW-Authenticate header.
      Parameters:
      scheme - authentication scheme to request
      params - challenge attributes for informing the client of how to authenticate
      Returns:
      authentication challenge
      See Also:

    • parseAuthenticateHeader

      public static Iterator<IuWebAuthenticationChallenge> parseAuthenticateHeader(String wwwAuthenticate)
      Parses challenge parameters from a WWW-Authenticate header.
      Parameters:
      wwwAuthenticate - WWW-Authenticate header challenge value
      Returns:
      Parsed authentication challenge parameters

    • validateUserAgent

      public static void validateUserAgent(String userAgent)
      Validates a user-agent header value.

      User-Agent = product *( RWS ( product / comment ) )

      Parameters:
      userAgent - user-agent header value
      See Also:

    • parseQueryString

      public static Map<String,? extends Iterable<String>> parseQueryString(String queryString)
      Parses a query string.
      Parameters:
      queryString - query string
      Returns:
      Map

    • createQueryString

      public static String createQueryString(Map<String,? extends Iterable<String>> params)
      Creates a query string from a map.
      Parameters:
      params - Map of parameter values
      Returns:
      query string

    • parseHeader

      public static Map<String,String> parseHeader(String headerValue)
      Parses a header value composed of key/value pairs separated by semicolon ';'.
      Parameters:
      headerValue - header value
      Returns:
      Map of header elements

    • normalizeHeaderName

      public static String normalizeHeaderName(String headerName) throws IllegalArgumentException
      Validates and normalizes case for an HTTP header name.

      Follows each hyphen '-' character with an upper case character; converts other characters to lower case

      Parameters:
      headerName - HTTP header name
      Returns:
      String
      Throws:
      IllegalArgumentException - If the name contains non-alphabetic characters other than hyphen '-', or if the name begins or ends with a hyphen.

    • describeStatus

      public static String describeStatus(int statusCode)
      Describes an HTTP status code.
      Parameters:
      statusCode - HTTP status code
      Returns:
      String

    • getInetAddress

      public static InetAddress getInetAddress(String hostname)
      Resolves and caches the IP address for a host name.
      Parameters:
      hostname - host name
      Returns:
      resolved InetAddress

    • isInetAddressInRange

      public static boolean isInetAddressInRange(InetAddress address, String range)
      Determines whether or not an IP address is included in a CIDR range.
      Parameters:
      address - address
      range - CIDR range
      Returns:
      true if the range includes the address; else false