This documentation differs from the official API. Jadeite adds extra features to the API including: variable font sizes, constructions examples, placeholders for classes and methods, and auto-generated “See Also” links. Additionally it is missing some items found in standard Javadoc documentation, including: generics type information, “Deprecated” tags and comments, “See Also” links, along with other minor differences. Please send any questions or feedback to bam@cs.cmu.edu.


java.net
class URLStreamHandler

java.lang.Object extended by java.net.URLStreamHandler

public abstract class URLStreamHandler
extends Object

The abstract class URLStreamHandler is the common superclass for all stream protocol handlers. A stream protocol handler knows how to make a connection for a particular protocol type, such as http, ftp, or gopher.

In most cases, an instance of a URLStreamHandler subclass is not created directly by an application. Rather, the first time a protocol name is encountered when constructing a URL, the appropriate stream protocol handler is automatically loaded.

See Also (auto-generated):

URL

InputStream


Constructor Summary

          
 
Method Summary
protected boolean
equals(URL u1, URL u2)

          Provides the default equals calculation.
protected int

          Returns the default port for a URL parsed by this handler.
protected InetAddress

          Get the IP address of our host.
protected int

          Provides the default hash calculation.
protected boolean
hostsEqual(URL u1, URL u2)

          Compares the host components of two URLs.
protected abstract URLConnection

          Opens a connection to the object referenced by the URL argument.
protected URLConnection

          Same as openConnection(URL), except that the connection will be made through the specified proxy; Protocol handlers that do not support proxying will ignore the proxy parameter and make a normal connection.
protected void
parseURL(URL u, String spec, int start, int limit)

          Parses the string representation of a URL into a URL object.
protected boolean
sameFile(URL u1, URL u2)

          Compare two urls to see whether they refer to the same file, i.e., having the same protocol, host, port, and path.
protected void
setURL(URL u, String protocol, String host, int port, String file, String ref)

          Sets the fields of the URL argument to the indicated values.
protected void
setURL(URL u, String protocol, String host, int port, String authority, String userInfo, String path, String query, String ref)

          Sets the fields of the URL argument to the indicated values.
protected String

          Converts a URL of a specific protocol to a String.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

URLStreamHandler

public URLStreamHandler()
Method Detail

equals

protected boolean equals(URL u1,
                         URL u2)
Provides the default equals calculation. May be overidden by handlers for other protocols that have different requirements for equals(). This method requires that none of its arguments is null. This is guaranteed by the fact that it is only called by java.net.URL class.

Parameters:
u1 - a URL object
u2 - a URL object
Returns:
true if the two urls are considered equal, ie. they refer to the same fragment in the same file.

getDefaultPort

protected int getDefaultPort()
Returns the default port for a URL parsed by this handler. This method is meant to be overidden by handlers with default port numbers.

Returns:
the default port for a URL parsed by this handler.

getHostAddress

protected synchronized InetAddress getHostAddress(URL u)
Get the IP address of our host. An empty host field or a DNS failure will result in a null return.

Parameters:
u - a URL object
Returns:
an InetAddress representing the host IP address.

hashCode

protected int hashCode(URL u)
Provides the default hash calculation. May be overidden by handlers for other protocols that have different requirements for hashCode calculation.

Parameters:
u - a URL object
Returns:
an int suitable for hash table indexing

hostsEqual

protected boolean hostsEqual(URL u1,
                             URL u2)
Compares the host components of two URLs.

Parameters:
u1 - the URL of the first host to compare
u2 - the URL of the second host to compare
Returns:
true if and only if they are equal, false otherwise.

openConnection

protected abstract URLConnection openConnection(URL u)
                                         throws IOException
Opens a connection to the object referenced by the URL argument. This method should be overridden by a subclass.

If for the handler's protocol (such as HTTP or JAR), 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.

Parameters:
u - the URL that this connects to.
Returns:
a URLConnection object for the URL.
Throws:
IOException - if an I/O error occurs while opening the connection.

openConnection

protected URLConnection openConnection(URL u,
                                       Proxy p)
                                throws IOException
Same as openConnection(URL), except that the connection will be made through the specified proxy; Protocol handlers that do not support proxying will ignore the proxy parameter and make a normal connection. Calling this method preempts the system's default ProxySelector settings.

Parameters:
u - the URL that this connects to.
p - the proxy through which the connection will be made. If direct connection is desired, Proxy.NO_PROXY should be specified.
Returns:
a URLConnection object for the URL.
Throws:
IOException - if an I/O error occurs while opening the connection.

parseURL

protected void parseURL(URL u,
                        String spec,
                        int start,
                        int limit)
Parses the string representation of a URL into a URL object.

If there is any inherited context, then it has already been copied into the URL argument.

The parseURL method of URLStreamHandler parses the string representation as if it were an http specification. Most URL protocol families have a similar parsing. A stream protocol handler for a protocol that has a different syntax must override this routine.

Parameters:
u - the URL to receive the result of parsing the spec.
spec - the String representing the URL that must be parsed.
start - the character index at which to begin parsing. This is just past the ':' (if there is one) that specifies the determination of the protocol name.
limit - the character position to stop parsing at. This is the end of the string or the position of the "#" character, if present. All information after the sharp sign indicates an anchor.

sameFile

protected boolean sameFile(URL u1,
                           URL u2)
Compare two urls to see whether they refer to the same file, i.e., having the same protocol, host, port, and path. This method requires that none of its arguments is null. This is guaranteed by the fact that it is only called indirectly by java.net.URL class.

Parameters:
u1 - a URL object
u2 - a URL object
Returns:
true if u1 and u2 refer to the same file

setURL

protected void setURL(URL u,
                      String protocol,
                      String host,
                      int port,
                      String file,
                      String ref)
Sets the fields of the URL argument to the indicated values. Only classes derived from URLStreamHandler are supposed to be able to call the set method on a URL.

Parameters:
u - the URL to modify.
protocol - the protocol name. This value is ignored since 1.2.
host - the remote host value for the URL.
port - the port on the remote machine.
file - the file.
ref - the reference.

setURL

protected void setURL(URL u,
                      String protocol,
                      String host,
                      int port,
                      String authority,
                      String userInfo,
                      String path,
                      String query,
                      String ref)
Sets the fields of the URL argument to the indicated values. Only classes derived from URLStreamHandler are supposed to be able to call the set method on a URL.

Parameters:
u - the URL to modify.
protocol - the protocol name.
host - the remote host value for the URL.
port - the port on the remote machine.
authority - the authority part for the URL.
userInfo - the userInfo part of the URL.
path - the path component of the URL.
query - the query part for the URL.
ref - the reference.

toExternalForm

protected String toExternalForm(URL u)
Converts a URL of a specific protocol to a String.

Parameters:
u - the URL.
Returns:
a string representation of the URL argument.


This documentation differs from the official API. Jadeite adds extra features to the API including: variable font sizes, constructions examples, placeholders for classes and methods, and auto-generated “See Also” links. Additionally it is missing some items found in standard Javadoc documentation, including: generics type information, “Deprecated” tags and comments, “See Also” links, along with other minor differences. Please send any questions or feedback to bam@cs.cmu.edu.
This page displays the Jadeite version of the documention, which is derived from the offical documentation that contains this copyright notice:
Copyright 2008 Sun Microsystems, Inc. All rights reserved. Use is subject to license terms. Also see the documentation redistribution policy.
The official Sun™ documentation can be found here at http://java.sun.com/javase/6/docs/api/.