+++ /dev/null
-/* URL.java -- Uniform Resource Locator Class
- Copyright (C) 1998, 1999, 2000, 2002, 2003, 2004, 2005
- Free Software Foundation, Inc.
-
-This file is part of GNU Classpath.
-
-GNU Classpath is free software; you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2, or (at your option)
-any later version.
-
-GNU Classpath is distributed in the hope that it will be useful, but
-WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-General Public License for more details.
-
-You should have received a copy of the GNU General Public License
-along with GNU Classpath; see the file COPYING. If not, write to the
-Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
-02110-1301 USA.
-
-Linking this library statically or dynamically with other modules is
-making a combined work based on this library. Thus, the terms and
-conditions of the GNU General Public License cover the whole
-combination.
-
-As a special exception, the copyright holders of this library give you
-permission to link this library with independent modules to produce an
-executable, regardless of the license terms of these independent
-modules, and to copy and distribute the resulting executable under
-terms of your choice, provided that you also meet, for each linked
-independent module, the terms and conditions of the license of that
-module. An independent module is a module which is not derived from
-or based on this library. If you modify this library, you may extend
-this exception to your version of the library, but you are not
-obligated to do so. If you do not wish to do so, delete this
-exception statement from your version. */
-
-package java.net;
-
-import gnu.java.net.URLParseError;
-
-import java.io.IOException;
-import java.io.InputStream;
-import java.io.ObjectInputStream;
-import java.io.ObjectOutputStream;
-import java.io.Serializable;
-import java.security.AccessController;
-import java.security.PrivilegedAction;
-import java.util.HashMap;
-import java.util.StringTokenizer;
-
-
-/*
- * Written using on-line Java Platform 1.2 API Specification, as well
- * as "The Java Class Libraries", 2nd edition (Addison-Wesley, 1998).
- * Status: Believed complete and correct.
- */
-
-/**
- * This final class represents an Internet Uniform Resource Locator (URL).
- * For details on the syntax of URL's and what they can be used for,
- * refer to RFC 1738, available from <a
- * href="http://ds.internic.net/rfcs/rfc1738.txt">
- * http://ds.internic.net/rfcs/rfc1738.txt</a>
- * <p>
- * There are a great many protocols supported by URL's such as "http",
- * "ftp", and "file". This object can handle any arbitrary URL for which
- * a URLStreamHandler object can be written. Default protocol handlers
- * are provided for the "http" and "ftp" protocols. Additional protocols
- * handler implementations may be provided in the future. In any case,
- * an application or applet can install its own protocol handlers that
- * can be "chained" with other protocol hanlders in the system to extend
- * the base functionality provided with this class. (Note, however, that
- * unsigned applets cannot access properties by default or install their
- * own protocol handlers).
- * <p>
- * This chaining is done via the system property java.protocol.handler.pkgs
- * If this property is set, it is assumed to be a "|" separated list of
- * package names in which to attempt locating protocol handlers. The
- * protocol handler is searched for by appending the string
- * ".<protocol>.Handler" to each packed in the list until a hander is
- * found. If a protocol handler is not found in this list of packages, or if
- * the property does not exist, then the default protocol handler of
- * "gnu.java.net.<protocol>.Handler" is tried. If this is
- * unsuccessful, a MalformedURLException is thrown.
- * <p>
- * All of the constructor methods of URL attempt to load a protocol
- * handler and so any needed protocol handlers must be installed when
- * the URL is constructed.
- * <p>
- * Here is an example of how URL searches for protocol handlers. Assume
- * the value of java.protocol.handler.pkgs is "com.foo|com.bar" and the
- * URL is "news://comp.lang.java.programmer". URL would looking the
- * following places for protocol handlers:
- * <p><pre>
- * com.foo.news.Handler
- * com.bar.news.Handler
- * gnu.java.net.news.Handler
- * </pre><p>
- * If the protocol handler is not found in any of those locations, a
- * MalformedURLException would be thrown.
- * <p>
- * Please note that a protocol handler must be a subclass of
- * URLStreamHandler.
- * <p>
- * Normally, this class caches protocol handlers. Once it finds a handler
- * for a particular protocol, it never tries to look up a new handler
- * again. However, if the system property
- * gnu.java.net.nocache_protocol_handlers is set, then this
- * caching behavior is disabled. This property is specific to this
- * implementation. Sun's JDK may or may not do protocol caching, but it
- * almost certainly does not examine this property.
- * <p>
- * Please also note that an application can install its own factory for
- * loading protocol handlers (see setURLStreamHandlerFactory). If this is
- * done, then the above information is superseded and the behavior of this
- * class in loading protocol handlers is dependent on that factory.
- *
- * @author Aaron M. Renn (arenn@urbanophile.com)
- * @author Warren Levy (warrenl@cygnus.com)
- *
- * @see URLStreamHandler
- */
-public final class URL implements Serializable
-{
- private static final String DEFAULT_SEARCH_PATH =
- "gnu.java.net.protocol|gnu.inet";
-
- // Cached System ClassLoader
- private static ClassLoader systemClassLoader;
-
- /**
- * The name of the protocol for this URL.
- * The protocol is always stored in lower case.
- */
- private String protocol;
-
- /**
- * The "authority" portion of the URL.
- */
- private String authority;
-
- /**
- * The hostname or IP address of this protocol.
- * This includes a possible user. For example <code>joe@some.host.net</code>.
- */
- private String host;
-
- /**
- * The user information necessary to establish the connection.
- */
- private String userInfo;
-
- /**
- * The port number of this protocol or -1 if the port number used is
- * the default for this protocol.
- */
- private int port = -1; // Initialize for constructor using context.
-
- /**
- * The "file" portion of the URL. It is defined as <code>path[?query]</code>.
- */
- private String file;
-
- /**
- * The anchor portion of the URL.
- */
- private String ref;
-
- /**
- * This is the hashCode for this URL
- */
- private int hashCode;
-
- /**
- * The protocol handler in use for this URL
- */
- transient URLStreamHandler ph;
-
- /**
- * If an application installs its own protocol handler factory, this is
- * where we keep track of it.
- */
- private static URLStreamHandlerFactory factory;
- private static final long serialVersionUID = -7627629688361524110L;
-
- /**
- * This a table where we cache protocol handlers to avoid the overhead
- * of looking them up each time.
- */
- private static HashMap ph_cache = new HashMap();
-
- /**
- * Whether or not to cache protocol handlers.
- */
- private static boolean cache_handlers;
-
- static
- {
- String s = System.getProperty("gnu.java.net.nocache_protocol_handlers");
-
- if (s == null)
- cache_handlers = true;
- else
- cache_handlers = false;
- }
-
- /**
- * Constructs a URL and loads a protocol handler for the values passed as
- * arguments.
- *
- * @param protocol The protocol for this URL ("http", "ftp", etc)
- * @param host The hostname or IP address to connect to
- * @param port The port number to use, or -1 to use the protocol's
- * default port
- * @param file The "file" portion of the URL.
- *
- * @exception MalformedURLException If a protocol handler cannot be loaded or
- * a parse error occurs.
- */
- public URL(String protocol, String host, int port, String file)
- throws MalformedURLException
- {
- this(protocol, host, port, file, null);
- }
-
- /**
- * Constructs a URL and loads a protocol handler for the values passed in
- * as arugments. Uses the default port for the protocol.
- *
- * @param protocol The protocol for this URL ("http", "ftp", etc)
- * @param host The hostname or IP address for this URL
- * @param file The "file" portion of this URL.
- *
- * @exception MalformedURLException If a protocol handler cannot be loaded or
- * a parse error occurs.
- */
- public URL(String protocol, String host, String file)
- throws MalformedURLException
- {
- this(protocol, host, -1, file, null);
- }
-
- /**
- * This method initializes a new instance of <code>URL</code> with the
- * specified protocol, host, port, and file. Additionally, this method
- * allows the caller to specify a protocol handler to use instead of
- * the default. If this handler is specified, the caller must have
- * the "specifyStreamHandler" permission (see <code>NetPermission</code>)
- * or a <code>SecurityException</code> will be thrown.
- *
- * @param protocol The protocol for this URL ("http", "ftp", etc)
- * @param host The hostname or IP address to connect to
- * @param port The port number to use, or -1 to use the protocol's default
- * port
- * @param file The "file" portion of the URL.
- * @param ph The protocol handler to use with this URL.
- *
- * @exception MalformedURLException If no protocol handler can be loaded
- * for the specified protocol.
- * @exception SecurityException If the <code>SecurityManager</code> exists
- * and does not allow the caller to specify its own protocol handler.
- *
- * @since 1.2
- */
- public URL(String protocol, String host, int port, String file,
- URLStreamHandler ph) throws MalformedURLException
- {
- if (protocol == null)
- throw new MalformedURLException("null protocol");
- protocol = protocol.toLowerCase();
- this.protocol = protocol;
-
- if (ph != null)
- {
- SecurityManager s = System.getSecurityManager();
- if (s != null)
- s.checkPermission(new NetPermission("specifyStreamHandler"));
-
- this.ph = ph;
- }
- else
- this.ph = getURLStreamHandler(protocol);
-
- if (this.ph == null)
- throw new MalformedURLException("Protocol handler not found: "
- + protocol);
-
- this.host = host;
- this.port = port;
- this.authority = (host != null) ? host : "";
- if (port >= 0 && host != null)
- this.authority += ":" + port;
-
- int hashAt = file.indexOf('#');
- if (hashAt < 0)
- {
- this.file = file;
- this.ref = null;
- }
- else
- {
- this.file = file.substring(0, hashAt);
- this.ref = file.substring(hashAt + 1);
- }
- hashCode = hashCode(); // Used for serialization.
- }
-
- /**
- * Initializes a URL from a complete string specification such as
- * "http://www.urbanophile.com/arenn/". First the protocol name is parsed
- * out of the string. Then a handler is located for that protocol and
- * the parseURL() method of that protocol handler is used to parse the
- * remaining fields.
- *
- * @param spec The complete String representation of a URL
- *
- * @exception MalformedURLException If a protocol handler cannot be found
- * or the URL cannot be parsed
- */
- public URL(String spec) throws MalformedURLException
- {
- this((URL) null, spec != null ? spec : "", (URLStreamHandler) null);
- }
-
- /**
- * This method parses a String representation of a URL within the
- * context of an existing URL. Principally this means that any
- * fields not present the URL are inheritied from the context URL.
- * This allows relative URL's to be easily constructed. If the
- * context argument is null, then a complete URL must be specified
- * in the URL string. If the protocol parsed out of the URL is
- * different from the context URL's protocol, then then URL String
- * is also expected to be a complete URL.
- *
- * @param context The context on which to parse the specification
- * @param spec The string to parse an URL
- *
- * @exception MalformedURLException If a protocol handler cannot be found
- * for the URL cannot be parsed
- */
- public URL(URL context, String spec) throws MalformedURLException
- {
- this(context, spec, (URLStreamHandler) null);
- }
-
- /**
- * Creates an URL from given arguments
- * This method parses a String representation of a URL within the
- * context of an existing URL. Principally this means that any fields
- * not present the URL are inheritied from the context URL. This allows
- * relative URL's to be easily constructed. If the context argument is
- * null, then a complete URL must be specified in the URL string.
- * If the protocol parsed out of the URL is different
- * from the context URL's protocol, then then URL String is also
- * expected to be a complete URL.
- * <p>
- * Additionally, this method allows the caller to specify a protocol handler
- * to use instead of the default. If this handler is specified, the caller
- * must have the "specifyStreamHandler" permission
- * (see <code>NetPermission</code>) or a <code>SecurityException</code>
- * will be thrown.
- *
- * @param context The context in which to parse the specification
- * @param spec The string to parse as an URL
- * @param ph The stream handler for the URL
- *
- * @exception MalformedURLException If a protocol handler cannot be found
- * or the URL cannot be parsed
- * @exception SecurityException If the <code>SecurityManager</code> exists
- * and does not allow the caller to specify its own protocol handler.
- *
- * @since 1.2
- */
- public URL(URL context, String spec, URLStreamHandler ph)
- throws MalformedURLException
- {
- /* A protocol is defined by the doc as the substring before a ':'
- * as long as the ':' occurs before any '/'.
- *
- * If context is null, then spec must be an absolute URL.
- *
- * 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 context. A bare file component is appended
- * to the context's file. The optional anchor is not inherited.
- */
-
- // If this is an absolute URL, then ignore context completely.
- // An absolute URL must have chars prior to "://" but cannot have a colon
- // right after the "://". The second colon is for an optional port value
- // and implies that the host from the context is used if available.
- int colon;
- int slash = spec.indexOf('/');
- if ((colon = spec.indexOf("://", 1)) > 0
- && ((colon < slash || slash < 0))
- && ! spec.regionMatches(colon, "://:", 0, 4))
- context = null;
-
- if ((colon = spec.indexOf(':')) > 0
- && (colon < slash || slash < 0))
- {
- // Protocol specified in spec string.
- protocol = spec.substring(0, colon).toLowerCase();
- if (context != null && context.protocol.equals(protocol))
- {
- // The 1.2 doc specifically says these are copied to the new URL.
- host = context.host;
- port = context.port;
- userInfo = context.userInfo;
- authority = context.authority;
- }
- }
- else if (context != null)
- {
- // Protocol NOT specified in spec string.
- // Use context fields (except ref) as a foundation for relative URLs.
- colon = -1;
- protocol = context.protocol;
- host = context.host;
- port = context.port;
- userInfo = context.userInfo;
- if (spec.indexOf(":/", 1) < 0)
- {
- file = context.file;
- if (file == null || file.length() == 0)
- file = "/";
- }
- authority = context.authority;
- }
- else // Protocol NOT specified in spec. and no context available.
- throw new MalformedURLException("Absolute URL required with null"
- + " context: " + spec);
-
- protocol = protocol.trim();
-
- if (ph != null)
- {
- SecurityManager s = System.getSecurityManager();
- if (s != null)
- s.checkPermission(new NetPermission("specifyStreamHandler"));
-
- this.ph = ph;
- }
- else
- this.ph = getURLStreamHandler(protocol);
-
- if (this.ph == null)
- throw new MalformedURLException("Protocol handler not found: "
- + protocol);
-
- // JDK 1.2 doc for parseURL specifically states that any '#' ref
- // is to be excluded by passing the 'limit' as the indexOf the '#'
- // if one exists, otherwise pass the end of the string.
- int hashAt = spec.indexOf('#', colon + 1);
-
- try
- {
- this.ph.parseURL(this, spec, colon + 1,
- hashAt < 0 ? spec.length() : hashAt);
- }
- catch (URLParseError e)
- {
- throw new MalformedURLException(e.getMessage());
- }
-
- if (hashAt >= 0)
- ref = spec.substring(hashAt + 1);
-
- hashCode = hashCode(); // Used for serialization.
- }
-
- /**
- * Test another URL for equality with this one. This will be true only if
- * the argument is non-null and all of the fields in the URL's match
- * exactly (ie, protocol, host, port, file, and ref). Overrides
- * Object.equals(), implemented by calling the equals method of the handler.
- *
- * @param obj The URL to compare with
- *
- * @return true if the URL is equal, false otherwise
- */
- public boolean equals(Object obj)
- {
- if (! (obj instanceof URL))
- return false;
-
- return ph.equals(this, (URL) obj);
- }
-
- /**
- * Returns the contents of this URL as an object by first opening a
- * connection, then calling the getContent() method against the connection
- *
- * @return A content object for this URL
- * @exception IOException If opening the connection or getting the
- * content fails.
- *
- * @since 1.3
- */
- public Object getContent() throws IOException
- {
- return openConnection().getContent();
- }
-
- /**
- * Gets the contents of this URL
- *
- * @param classes The allow classes for the content object.
- *
- * @return a context object for this URL.
- *
- * @exception IOException If an error occurs
- */
- public Object getContent(Class[] classes) throws IOException
- {
- // FIXME: implement this
- return getContent();
- }
-
- /**
- * Returns the file portion of the URL.
- * Defined as <code>path[?query]</code>.
- * Returns the empty string if there is no file portion.
- *
- * @return The filename specified in this URL, or an empty string if empty.
- */
- public String getFile()
- {
- return file == null ? "" : file;
- }
-
- /**
- * Returns the path of the URL. This is the part of the file before any '?'
- * character.
- *
- * @return The path specified in this URL, or null if empty.
- *
- * @since 1.3
- */
- public String getPath()
- {
- // The spec says we need to return an empty string, but some
- // applications depends on receiving null when the path is empty.
- if (file == null)
- return null;
- int quest = file.indexOf('?');
- return quest < 0 ? getFile() : file.substring(0, quest);
- }
-
- /**
- * Returns the authority of the URL
- *
- * @return The authority specified in this URL.
- *
- * @since 1.3
- */
- public String getAuthority()
- {
- return authority;
- }
-
- /**
- * Returns the host of the URL
- *
- * @return The host specified in this URL.
- */
- public String getHost()
- {
- int at = (host == null) ? -1 : host.indexOf('@');
- return at < 0 ? host : host.substring(at + 1, host.length());
- }
-
- /**
- * Returns the port number of this URL or -1 if the default port number is
- * being used.
- *
- * @return The port number
- *
- * @see #getDefaultPort()
- */
- public int getPort()
- {
- return port;
- }
-
- /**
- * Returns the default port of the URL. If the StreamHandler for the URL
- * protocol does not define a default port it returns -1.
- *
- * @return The default port of the current protocol.
- */
- public int getDefaultPort()
- {
- return ph.getDefaultPort();
- }
-
- /**
- * Returns the protocol of the URL
- *
- * @return The specified protocol.
- */
- public String getProtocol()
- {
- return protocol;
- }
-
- /**
- * Returns the ref (sometimes called the "# reference" or "anchor") portion
- * of the URL.
- *
- * @return The ref
- */
- public String getRef()
- {
- return ref;
- }
-
- /**
- * Returns the user information of the URL. This is the part of the host
- * name before the '@'.
- *
- * @return the user at a particular host or null when no user defined.
- */
- public String getUserInfo()
- {
- if (userInfo != null)
- return userInfo;
- int at = (host == null) ? -1 : host.indexOf('@');
- return at < 0 ? null : host.substring(0, at);
- }
-
- /**
- * Returns the query of the URL. This is the part of the file before the
- * '?'.
- *
- * @return the query part of the file, or null when there is no query part.
- */
- public String getQuery()
- {
- int quest = (file == null) ? -1 : file.indexOf('?');
- return quest < 0 ? null : file.substring(quest + 1, file.length());
- }
-
- /**
- * Returns a hashcode computed by the URLStreamHandler of this URL
- *
- * @return The hashcode for this URL.
- */
- public int hashCode()
- {
- if (hashCode != 0)
- return hashCode; // Use cached value if available.
- else
- return ph.hashCode(this);
- }
-
- /**
- * Returns a URLConnection object that represents a connection to the remote
- * object referred to by the URL. The URLConnection is created by calling the
- * openConnection() method of the protocol handler
- *
- * @return A URLConnection for this URL
- *
- * @exception IOException If an error occurs
- */
- public URLConnection openConnection() throws IOException
- {
- return ph.openConnection(this);
- }
-
- /**
- * Opens a connection to this URL and returns an InputStream for reading
- * from that connection
- *
- * @return An <code>InputStream</code> for this URL.
- *
- * @exception IOException If an error occurs
- */
- public InputStream openStream() throws IOException
- {
- return openConnection().getInputStream();
- }
-
- /**
- * Tests whether or not another URL refers to the same "file" as this one.
- * This will be true if and only if the passed object is not null, is a
- * URL, and matches all fields but the ref (ie, protocol, host, port,
- * and file);
- *
- * @param url The URL object to test with
- *
- * @return true if URL matches this URL's file, false otherwise
- */
- public boolean sameFile(URL url)
- {
- return ph.sameFile(this, url);
- }
-
- /**
- * Sets the specified fields of the URL. This is not a public method so
- * that only URLStreamHandlers can modify URL fields. This might be called
- * by the <code>parseURL()</code> method in that class. URLs are otherwise
- * constant. If the given protocol does not exist, it will keep the previously
- * set protocol.
- *
- * @param protocol The protocol name for this URL
- * @param host The hostname or IP address for this URL
- * @param port The port number of this URL
- * @param file The "file" portion of this URL.
- * @param ref The anchor portion of this URL.
- */
- protected void set(String protocol, String host, int port, String file,
- String ref)
- {
- URLStreamHandler protocolHandler = null;
- protocol = protocol.toLowerCase();
- if (! this.protocol.equals(protocol))
- protocolHandler = getURLStreamHandler(protocol);
-
- // It is an hidden feature of the JDK. If the protocol does not exist,
- // we keep the previously initialized protocol.
- if (protocolHandler != null)
- {
- this.ph = protocolHandler;
- this.protocol = protocol;
- }
- this.authority = "";
- this.port = port;
- this.host = host;
- this.file = file;
- this.ref = ref;
-
- if (host != null)
- this.authority += host;
- if (port >= 0)
- this.authority += ":" + port;
-
- hashCode = hashCode(); // Used for serialization.
- }
-
- /**
- * Sets the specified fields of the URL. This is not a public method so
- * that only URLStreamHandlers can modify URL fields. URLs are otherwise
- * constant. If the given protocol does not exist, it will keep the previously
- * set protocol.
- *
- * @param protocol The protocol name for this URL.
- * @param host The hostname or IP address for this URL.
- * @param port The port number of this URL.
- * @param authority The authority of this URL.
- * @param userInfo The user and password (if needed) of this URL.
- * @param path The "path" portion of this URL.
- * @param query The query of this URL.
- * @param ref The anchor portion of this URL.
- *
- * @since 1.3
- */
- protected void set(String protocol, String host, int port, String authority,
- String userInfo, String path, String query, String ref)
- {
- URLStreamHandler protocolHandler = null;
- protocol = protocol.toLowerCase();
- if (! this.protocol.equals(protocol))
- protocolHandler = getURLStreamHandler(protocol);
-
- // It is an hidden feature of the JDK. If the protocol does not exist,
- // we keep the previously initialized protocol.
- if (protocolHandler != null)
- {
- this.ph = protocolHandler;
- this.protocol = protocol;
- }
- this.host = host;
- this.userInfo = userInfo;
- this.port = port;
- this.authority = authority;
- if (query == null)
- this.file = path;
- else
- this.file = path + "?" + query;
- this.ref = ref;
- hashCode = hashCode(); // Used for serialization.
- }
-
- /**
- * Sets the URLStreamHandlerFactory for this class. This factory is
- * responsible for returning the appropriate protocol handler for
- * a given URL.
- *
- * @param fac The URLStreamHandlerFactory class to use
- *
- * @exception Error If the factory is alread set.
- * @exception SecurityException If a security manager exists and its
- * checkSetFactory method doesn't allow the operation
- */
- public static synchronized void setURLStreamHandlerFactory(URLStreamHandlerFactory fac)
- {
- if (factory != null)
- throw new Error("URLStreamHandlerFactory already set");
-
- // Throw an exception if an extant security mgr precludes
- // setting the factory.
- SecurityManager s = System.getSecurityManager();
- if (s != null)
- s.checkSetFactory();
- factory = fac;
- }
-
- /**
- * Returns a String representing this URL. The String returned is
- * created by calling the protocol handler's toExternalForm() method.
- *
- * @return A string for this URL
- */
- public String toExternalForm()
- {
- // Identical to toString().
- return ph.toExternalForm(this);
- }
-
- /**
- * Returns a String representing this URL. Identical to toExternalForm().
- * The value returned is created by the protocol handler's
- * toExternalForm method. Overrides Object.toString()
- *
- * @return A string for this URL
- */
- public String toString()
- {
- // Identical to toExternalForm().
- return ph.toExternalForm(this);
- }
-
- /**
- * This internal method is used in two different constructors to load
- * a protocol handler for this URL.
- *
- * @param protocol The protocol to load a handler for
- *
- * @return A URLStreamHandler for this protocol, or null when not found.
- */
- private static synchronized URLStreamHandler getURLStreamHandler(String protocol)
- {
- URLStreamHandler ph = null;
-
- // First, see if a protocol handler is in our cache.
- if (cache_handlers)
- {
- if ((ph = (URLStreamHandler) ph_cache.get(protocol)) != null)
- return ph;
- }
-
- // If a non-default factory has been set, use it to find the protocol.
- if (factory != null)
- {
- ph = factory.createURLStreamHandler(protocol);
- }
- else if (protocol.equals("core"))
- {
- ph = new gnu.java.net.protocol.core.Handler();
- }
- else if (protocol.equals("file"))
- {
- // This is an interesting case. It's tempting to think that we
- // could call Class.forName ("gnu.java.net.protocol.file.Handler") to
- // get the appropriate class. Unfortunately, if we do that the
- // program will never terminate, because getURLStreamHandler is
- // eventually called by Class.forName.
- //
- // Treating "file" as a special case is the minimum that will
- // fix this problem. If other protocols are required in a
- // statically linked application they will need to be handled in
- // the same way as "file".
- ph = new gnu.java.net.protocol.file.Handler();
- }
-
- // Non-default factory may have returned null or a factory wasn't set.
- // Use the default search algorithm to find a handler for this protocol.
- if (ph == null)
- {
- // Get the list of packages to check and append our default handler
- // to it, along with the JDK specified default as a last resort.
- // Except in very unusual environments the JDK specified one shouldn't
- // ever be needed (or available).
- String ph_search_path =
- System.getProperty("java.protocol.handler.pkgs");
-
- // Tack our default package on at the ends.
- if (ph_search_path != null)
- ph_search_path += "|" + DEFAULT_SEARCH_PATH;
- else
- ph_search_path = DEFAULT_SEARCH_PATH;
-
- // Finally loop through our search path looking for a match.
- StringTokenizer pkgPrefix = new StringTokenizer(ph_search_path, "|");
-
- // Cache the systemClassLoader
- if (systemClassLoader == null)
- {
- systemClassLoader = (ClassLoader) AccessController.doPrivileged
- (new PrivilegedAction() {
- public Object run()
- {
- return ClassLoader.getSystemClassLoader();
- }
- });
- }
-
- do
- {
- try
- {
- // Try to get a class from the system/application
- // classloader, initialize it, make an instance
- // and try to cast it to a URLStreamHandler.
- String clsName =
- (pkgPrefix.nextToken() + "." + protocol + ".Handler");
- Class c = Class.forName(clsName, true, systemClassLoader);
- ph = (URLStreamHandler) c.newInstance();
- }
- catch (ThreadDeath death)
- {
- throw death;
- }
- catch (Throwable t)
- {
- // Ignored.
- }
- }
- while (ph == null && pkgPrefix.hasMoreTokens());
- }
-
- // Update the hashtable with the new protocol handler.
- if (ph != null && cache_handlers)
- ph_cache.put(protocol, ph);
- else
- ph = null;
-
- return ph;
- }
-
- private void readObject(ObjectInputStream ois)
- throws IOException, ClassNotFoundException
- {
- ois.defaultReadObject();
- this.ph = getURLStreamHandler(protocol);
- if (this.ph == null)
- throw new IOException("Handler for protocol " + protocol + " not found");
- }
-
- private void writeObject(ObjectOutputStream oos) throws IOException
- {
- oos.defaultWriteObject();
- }
-
- /**
- * Returns the equivalent <code>URI</code> object for this <code>URL</code>.
- * This is the same as calling <code>new URI(this.toString())</code>.
- * RFC2396-compliant URLs are guaranteed a successful conversion to
- * a <code>URI</code> instance. However, there are some values which
- * form valid URLs, but which do not also form RFC2396-compliant URIs.
- *
- * @throws URISyntaxException if this URL is not RFC2396-compliant,
- * and thus can not be successfully converted to a URI.
- */
- public URI toURI()
- throws URISyntaxException
- {
- return new URI(toString());
- }
-
-}
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