Class URL represents a Uniform Resource Locator, a pointer to a "resource" on the World Wide Web. More...

#include <src/main/decaf/net/URL.h>

Public Member Functions
	URL (const decaf::lang::String &url)
	Creates a URL object from the String representation. More...

	URL (const URL &context, const decaf::lang::String &spec)
	Creates a URL by parsing the given spec within a specified context. More...

	URL (const decaf::lang::String &protocol, const decaf::lang::String &host, int port, const decaf::lang::String &file, URLStreamHandler *handler)
	Creates a URL object from the specified protocol, host, port number, file, and handler. More...

	URL (const decaf::lang::String &protocol, const decaf::lang::String &host, const decaf::lang::String &file)
	Creates a URL from the specified protocol name, host name, and file name. More...

	URL (const decaf::lang::String &protocol, const decaf::lang::String &host, int port, const decaf::lang::String &file)
	Creates a new URL instance using the given arguments. More...

	URL (const URL &context, const decaf::lang::String &spec, URLStreamHandler *handler)
	Creates a URL by parsing the given spec with the specified handler within a specified context. More...

virtual	~URL ()

bool	equals (const URL &other) const
	Compares this URL for equality with another URL. More...

decaf::lang::String	getAuthority () const
	Gets the authority part of this URL. More...

int	getDefaultPort () const
	Gets the default port number of the protocol associated with this URL. More...

decaf::lang::String	getFile () const
	Gets the file name of this URL. More...

decaf::lang::String	getHost () const
	Gets the host name of this URL, if applicable. More...

decaf::lang::String	getPath () const
	Gets the path part of this URL. More...

decaf::lang::String	getUserInfo () const
	Gets the user Info part of this URL. More...

int	getPort () const
	Gets the port of this URL. More...

decaf::lang::String	getProtocol () const
	Gets the protocol of this URL. More...

decaf::lang::String	getQuery () const
	Gets the query part of this URL. More...

decaf::lang::String	getRef () const
	Gets the anchor or "reference" portion of this URL. More...

int	hashCode () const
	Creates an integer hash code for this URL which is used in hash based collections. More...

URLConnection *	openConnection ()
	Returns a URLConnection object that represents a connection to the remote object referred to by the URL. More...

URLConnection *	openConnection (const Proxy *proxy)
	Same basic functionality as openConnection() is provided here, except that the connection will be made through the specified proxy; Protocol handlers that do not support proxing will ignore the proxy parameter and make a normal connection. More...

decaf::io::InputStream *	openStream ()
	Shortcut method to opens a connection to this URL and fetch an InputStream for reading from that connection. More...

bool	sameFile (const URL &other) const
	Compares this URL to the other ignoring the fragment portion to determine if both reference the same remote object. More...

decaf::lang::String	toExternalForm () const
	Constructs a string representation of this URL, by calling the toExternalForm method of the stream protocol handler for this object. More...

std::string	toString () const
	Calls toExternalForm to create a string representation of this URL. More...

URI	toURI () const
	Returns a URI instance that is the equivalent of this URL. More...

Static Public Member Functions
static void	setURLStreamHandlerFactory (URLStreamHandlerFactory *factory)
	Sets an application's URLStreamHandlerFactory. More...

Friends
class	URLStreamHandler

Detailed Description

Class URL represents a Uniform Resource Locator, a pointer to a "resource" on the World Wide Web.

A resource can be something as simple as a file or a directory, or it can be a reference to a more complicated object, such as a query to a database or to a search engine. More information on the types of URLs and their formats can be found at:

http://www.ksc.nasa.gov/facts/internet/url-primer.html

In general, a URL can be broken into several parts. The previous example of a URL indicates that the protocol to use is http (HyperText Transfer Protocol) and that the information resides on a host machine named www.ksc.nasa.gov. The information on that host machine is named /facts/internet/url-primer.html. The exact meaning of this name on the host machine is both protocol dependent and host dependent. The information normally resides in a file, but it could be generated on the fly. This component of the URL is called the path component.

A URL can optionally specify a "port", which is the port number to which the TCP connection is made on the remote host machine. If the port is not specified, the default port for the protocol is used instead. For example, the default port for http is 80. An alternative port could be specified as:

http://www.ksc.nasa.gov:80/facts/internet/url-primer.html

The syntax of URL is defined by RFC 2396: Uniform Resource Identifiers (URI): Generic Syntax, amended by RFC 2732: Format for Literal IPv6 Addresses in URLs. The Literal IPv6 address format also supports scope_ids. The syntax and usage of scope_ids is described here.

A URL may have appended to it a "fragment", also known as a "ref" or a "reference". The fragment is indicated by the sharp sign character "#" followed by more characters. For example,

http://www.apache.org/cms/index.html#chapter1

This fragment is not technically part of the URL. Rather, it indicates that after the specified resource is retrieved, the application is specifically interested in that part of the document that has the tag chapter1 attached to it. The meaning of a tag is resource specific.

An application can also specify a "relative URL", which contains only enough information to reach the resource relative to another URL. Relative URLs are frequently used within HTML pages. For example, if the contents of the URL:

http://www.apache.org/cms/index.html

contained within it the relative URL:

FAQ.html

it would be a shorthand for:

http://www.apache.org/cms/FAQ.html

The relative URL need not specify all the components of a URL. If the protocol, host name, or port number is missing, the value is inherited from the fully specified URL. The file component must be specified. The optional fragment is not inherited.

The URL class does not itself encode or decode any URL components according to the escaping mechanism defined in RFC2396. It is the responsibility of the caller to encode any fields, which need to be escaped prior to calling URL, and also to decode any escaped fields, that are returned from URL. Furthermore, because URL has no knowledge of URL escaping, it does not recognise equivalence between the encoded or decoded form of the same URL. For example, the two URLs:

http://foo.com/hello world/ and http://foo.com/hello%20world

would be considered not equal to each other.

Note, the URI class does perform escaping of its component fields in certain circumstances. The recommended way to manage the encoding and decoding of URLs is to use URI, and to convert between these two classes using toURI() and URI.toURL().

The URLEncoder and URLDecoder classes can also be used, but only for HTML form encoding, which is not the same as the encoding scheme defined in RFC2396.

Since: 1.0

Constructor & Destructor Documentation

decaf::net::URL::URL ( const decaf::lang::String & url )

Creates a URL object from the String representation.

This constructor is equivalent to a call to the two-argument constructor with a empty first argument.

Parameters

url	the String to parse as a URL.

Exceptions

MalformedURLException If the string specifies an unknown protocol.

decaf::net::URL::URL	(	const URL &	context,
		const decaf::lang::String &	spec
	)

Creates a URL by parsing the given spec within a specified context.

The new URL is created from the given context URL and the spec argument as described in RFC2396 "Uniform Resource Identifiers : Generic * Syntax" :

<scheme>://<authority><path>?<query>#<fragment>

The reference is parsed into the scheme, authority, path, query and fragment parts. If the path component is empty and the scheme, authority, and query components are undefined, then the new URL is a reference to the current document. Otherwise, the fragment and query parts present in the spec are used in the new URL.

If the scheme component is defined in the given spec and does not match the scheme of the context, then the new URL is created as an absolute URL based on the spec alone. Otherwise the scheme component is inherited from the context URL.

If the authority component is present in the spec then the spec is treated as absolute and the spec authority and path will replace the context authority and path. If the authority component is absent in the spec then the authority of the new URL will be inherited from the context.

If the spec's path component begins with a slash character "/" then the path is treated as absolute and the spec path replaces the context path.

Otherwise, the path is treated as a relative path and is appended to the context path, as described in RFC2396. Also, in this case, the path is canonicalized through the removal of directory changes made by occurrences of ".." and ".".

For a more detailed description of URL parsing, refer to RFC2396.

Parameters

context	the URL which is used as the context.
spec	the URL string representation which has to be parsed.

Exceptions

MalformedURLException if the given string spec could not be parsed as a URL or an invalid protocol has been found.

decaf::net::URL::URL	(	const decaf::lang::String &	protocol,
		const decaf::lang::String &	host,
		int	port,
		const decaf::lang::String &	file,
		URLStreamHandler *	handler
	)

Creates a URL object from the specified protocol, host, port number, file, and handler.

Specifying a port number of -1 indicates that the URL should use the default port for the protocol. Specifying a handler of null indicates that the URL should use a default stream handler for the protocol, as outlined for:

URL(const String&, const String&, int, const String&)

If a URLStreamHandler instance is provided then this class will take ownership of the object and delete at a later time.

Parameters

protocol	the name of the protocol to use.
host	the name of the host.
port	the port number on the host.
file	the file on the host
handler	the stream handler for the URL.

Exceptions

MalformedURLException if an unknown protocol is specified.

decaf::net::URL::URL	(	const decaf::lang::String &	protocol,
		const decaf::lang::String &	host,
		const decaf::lang::String &	file
	)

Creates a URL from the specified protocol name, host name, and file name.

The default port for the specified protocol is used.

This method is equivalent to calling the four-argument constructor with the arguments being protocol, host, -1, and file. No validation of the inputs is performed by this constructor.

Parameters

protocol	the name of the protocol to use.
host	the name of the host.
file	the file on the host

Exceptions

MalformedURLException if an unknown protocol is specified.

decaf::net::URL::URL	(	const decaf::lang::String &	protocol,
		const decaf::lang::String &	host,
		int	port,
		const decaf::lang::String &	file
	)

Creates a new URL instance using the given arguments.

The URL uses the specified port instead of the default port for the given protocol.

Parameters

protocol	the name of the protocol to use.
host	the name of the host.
port	the specific port number of the URL. Value of -1 represents the default port of the protocol.
file	the name of the resource.

Exceptions

MalformedURLException if the combination of all arguments do not represent a valid URL or the protocol is invalid.

decaf::net::URL::URL	(	const URL &	context,
		const decaf::lang::String &	spec,
		URLStreamHandler *	handler
	)

Creates a URL by parsing the given spec with the specified handler within a specified context.

If the handler is NULL, the parsing occurs as with the two argument constructor.

If a stream handler instance is passed then this object takes ownership of it and will destroy the resources when no longer needed.

Parameters

context	the URL which is used as the context.
spec	the URL string representation which has to be parsed.
handler	the stream handler for the URL.

Exceptions

MalformedURLException if an unknown protocol is specified.

virtual decaf::net::URL::~URL ( )

virtual

Member Function Documentation

bool decaf::net::URL::equals ( const URL & other ) const

Compares this URL for equality with another URL.

Two URL objects are equal if they have the same protocol, reference equivalent hosts, have the same port number on the host, and the same file and fragment of the file.

Two hosts are considered equivalent if both host names can be resolved into the same IP addresses; else if either host name can't be resolved, the host names must be equal without regard to case; or both host names equal to empty string.

Since hosts comparison requires name resolution, this operation is a blocking operation.

Returns: true if this URL is considered equal to the given URL instance.

decaf::lang::String decaf::net::URL::getAuthority ( ) const

Gets the authority part of this URL.

Returns: the authority part of this URL.

int decaf::net::URL::getDefaultPort ( ) const

Gets the default port number of the protocol associated with this URL.

If the URL scheme or the URLStreamHandler for the URL do not define a default port number, then -1 is returned.

Returns: the default port for the given scheme.

decaf::lang::String decaf::net::URL::getFile ( ) const

Gets the file name of this URL.

The returned file portion will be the same as getPath(), plus the concatenation of the value of getQuery(), if any. If there is no query portion, this method and getPath() will return identical results.

Returns: the file name associated with this URL.

decaf::lang::String decaf::net::URL::getHost ( ) const

Gets the host name of this URL, if applicable.

The format of the host conforms to RFC 2732, i.e. for a literal IPv6 address, this method will return the IPv6 address enclosed in square brackets ('[' and ']').

Returns: the host name for this URL.

decaf::lang::String decaf::net::URL::getPath ( ) const

Gets the path part of this URL.

Returns: the path part of this URL.

int decaf::net::URL::getPort ( ) const

Gets the port of this URL.

Returns: the port of this URL or -1 if not set.

decaf::lang::String decaf::net::URL::getProtocol ( ) const

Gets the protocol of this URL.

Returns: the path part of this URL.

decaf::lang::String decaf::net::URL::getQuery ( ) const

Gets the query part of this URL.

Returns: the query part of this URL or empty string if not set.

decaf::lang::String decaf::net::URL::getRef ( ) const

Gets the anchor or "reference" portion of this URL.

Returns: the anchor or "reference" portion of this URL.

decaf::lang::String decaf::net::URL::getUserInfo ( ) const

Gets the user Info part of this URL.

Returns: the user info part of this URL.

int decaf::net::URL::hashCode ( ) const

Creates an integer hash code for this URL which is used in hash based collections.

The hash code is based upon all the URL components relevant for URL comparison which means that the host resolution may cause this operation to block.

Returns: the integer has code for this URL.

URLConnection* decaf::net::URL::openConnection ( )

Returns a URLConnection object that represents a connection to the remote object referred to by the URL.

A new connection is opened every time by calling the openConnection method of the protocol handler for this URL.

If for the URL's protocol (such as HTTP), there exists a public, specialized URLConnection subclass belonging to one of the following packages or one of their subpackages: java.lang, java.io, java.util, java.net, the connection returned will be of that subclass. For example, for HTTP an HttpURLConnection will be returned, and for JAR a JarURLConnection will be returned.

Returns: a new URLConnection instance for this URL.

Exceptions

IOException if an error occurs while opening the connection.

URLConnection* decaf::net::URL::openConnection ( const Proxy * proxy )

Same basic functionality as openConnection() is provided here, except that the connection will be made through the specified proxy; Protocol handlers that do not support proxing will ignore the proxy parameter and make a normal connection.

Parameters

proxy The proxy instance to use to make the connection.

Returns: a new URLConnection instance for this URL.

Exceptions

IOException	if an error occurs while opening the connection.
IllegalArgumentException	if proxy is null, or proxy has the wrong type.
UnsupportedOperationException	if this method is not supported.

decaf::io::InputStream* decaf::net::URL::openStream ( )

Shortcut method to opens a connection to this URL and fetch an InputStream for reading from that connection.

Returns: an InputStream that reads from this URL's location.

Exceptions

IOException if an error occurs.

bool decaf::net::URL::sameFile ( const URL & other ) const

Compares this URL to the other ignoring the fragment portion to determine if both reference the same remote object.

Returns: true if both URL's reference the same external object.

static void decaf::net::URL::setURLStreamHandlerFactory ( URLStreamHandlerFactory * factory )

static

Sets an application's URLStreamHandlerFactory.

This method can be called at most once.

The URLStreamHandlerFactory instance is used to construct a stream protocol handler from a protocol name. The provided factory becomes the property of this runtime and will be deleted at shutdown.

Parameters

factory the desired factory.

Exceptions

Exception if there is already a set factory.

decaf::lang::String decaf::net::URL::toExternalForm ( ) const

Constructs a string representation of this URL, by calling the toExternalForm method of the stream protocol handler for this object.

Returns: the string representation of this URL.

std::string decaf::net::URL::toString ( ) const

Calls toExternalForm to create a string representation of this URL.

Returns: the string representation of this URL.

URI decaf::net::URL::toURI ( ) const

Returns a URI instance that is the equivalent of this URL.

Returns: the URI that is the equivalent of this URL.

Friends And Related Function Documentation

friend class URLStreamHandler

friend

The documentation for this class was generated from the following file:

src/main/decaf/net/URL.h

Public Member Functions

Static Public Member Functions

Friends

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Friends And Related Function Documentation