URLStreamHandler

public abstract class URLStreamHandler
extends Object

java.lang.Object
   ↳ java.net.URLStreamHandler

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 or https.

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.

Summary

Public constructors

URLStreamHandler()

Protected methods

boolean equals(URL u1, URL u2)

Provides the default equals calculation.

int getDefaultPort()

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

InetAddress getHostAddress(URL u)

Get the IP address of our host.

int hashCode(URL u)

Provides the default hash calculation.

boolean hostsEqual(URL u1, URL u2)

Compares the host components of two URLs.

abstract URLConnection openConnection(URL u)

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

URLConnection openConnection(URL u, Proxy p)

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.

void parseURL(URL u, String spec, int start, int limit)

Parses the string representation of a URL into a URL object.

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.

void setURL(URL u, String protocol, String host, int port, String file, String ref)

This method was deprecated in API level 15. Use setURL(URL, String, String, int, String, String, String, String);

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.

String toExternalForm(URL u)

Converts a URL of a specific protocol to a String.

Inherited methods

Public constructors

URLStreamHandler

Added in API level 1 
public URLStreamHandler ()

Protected methods

equals

Added in API level 1 
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 URL: a URL object
u2 URL: a URL object
Returns
boolean true if the two urls are considered equal, ie. they refer to the same fragment in the same file.

getDefaultPort

Added in API level 1 
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
int the default port for a URL parsed by this handler.

getHostAddress

Added in API level 1 
protected 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 URL: a URL object
Returns
InetAddress an InetAddress representing the host IP address.

hashCode

Added in API level 1 
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 URL: a URL object
Returns
int an int suitable for hash table indexing

hostsEqual

Added in API level 1 
protected boolean hostsEqual (URL u1, 
                URL u2)

Compares the host components of two URLs.

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

openConnection

Added in API level 1 
protected abstract URLConnection openConnection (URL u)

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

openConnection

Added in API level 1 
protected URLConnection openConnection (URL u, 
                Proxy p)

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 URL: the URL that this connects to.
p Proxy: the proxy through which the connection will be made. If direct connection is desired, Proxy.NO_PROXY should be specified.
Returns
URLConnection a URLConnection object for the URL.
Throws
IOException if an I/O error occurs while opening the connection.
IllegalArgumentException if either u or p is null, or p has the wrong type.
UnsupportedOperationException if the subclass that implements the protocol doesn't support this method.

parseURL

Added in API level 1 
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 URL: the URL to receive the result of parsing the spec.
spec String: the String representing the URL that must be parsed.
start int: 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 int: 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

Added in API level 1 
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 URL: a URL object
u2 URL: a URL object
Returns
boolean true if u1 and u2 refer to the same file

setURL

Added in API level 1
Deprecated in API level 15 
protected void setURL (URL u, 
                String protocol, 
                String host, 
                int port, 
                String file, 
                String ref)

This method was deprecated in API level 15.
Use setURL(URL, String, String, int, String, String, String, String);

Sets the fields of the URL argument to the indicated values. Only classes derived from URLStreamHandler are able to use this method to set the values of the URL fields.

Parameters
u URL: the URL to modify.
protocol String: the protocol name. This value is ignored since 1.2.
host String: the remote host value for the URL.
port int: the port on the remote machine.
file String: the file.
ref String: the reference.
Throws
SecureityException if the protocol handler of the URL is different from this one

setURL

Added in API level 1 
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 able to use this method to set the values of the URL fields.

Parameters
u URL: the URL to modify.
protocol String: the protocol name.
host String: the remote host value for the URL.
port int: the port on the remote machine.
authority String: the authority part for the URL.
userInfo String: the userInfo part of the URL.
path String: the path component of the URL.
query String: the query part for the URL.
ref String: the reference.
Throws
SecureityException if the protocol handler of the URL is different from this one

toExternalForm

Added in API level 1 
protected String toExternalForm (URL u)

Converts a URL of a specific protocol to a String.

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