HTTPClient

Class Util

java.lang.Object

HTTPClient.Util

public class Util
extends Object

This class holds various utility methods.

Version:

0.3-3 06/05/2001

Author:

Ronald Tschalär

Method Summary

Methods

Modifier and Type	Method and Description
static String	assembleHeader(Vector pheader) Assembles a Vector of HttpHeaderElements into a full header string.
static int	defaultPort(String protocol) Deprecated. use URI.defaultPort() instead
static String	dequoteString(String str) Replace quoted characters by their unquoted version.
static HttpHeaderElement	getElement(Vector header, String name) Get the HttpHeaderElement with the name name.
static String	getFragment(String resource) Extract the fragment part from an http resource.
static String	getParameter(String param, String hdr) retrieves the value associated with the parameter param in a given header string.
static String	getParams(String resource) Extract the params part from an http resource.
static String	getPath(String resource) Extract the path from an http resource.
static String	getQuery(String resource) Extract the query string from an http resource.
static boolean	hasToken(String header, String token) Determines if the given header contains a certain token.
static String	httpDate(Date date) This returns a string containing the date and time in date formatted according to a subset of RFC-1123.
static Vector	parseHeader(String header) This parses the value part of a header.
static Vector	parseHeader(String header, boolean dequote) This parses the value part of a header.
static String	quoteString(String str, String qlist) Replace given characters by their quoted version.
static boolean	sameHttpURL(URL url1, URL url2) Compares two http urls for equality.
static boolean	wildcardMatch(String pattern, String name) Match pattern against name, where pattern may contain wildcards ('*').

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

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:

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:

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:

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:

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:

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