/*
 * Copyright (c) 1995, 2018, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation. Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code 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
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package java.net;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.spi.URLStreamHandlerProvider;
import java.nio.file.Path;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.Hashtable;
import java.io.InvalidObjectException;
import java.io.ObjectStreamException;
import java.io.ObjectStreamField;
import java.io.ObjectInputStream.GetField;
import java.util.Iterator;
import java.util.Locale;
import java.util.NoSuchElementException;
import java.util.ServiceConfigurationError;
import java.util.ServiceLoader;

import jdk.internal.access.JavaNetURLAccess;
import jdk.internal.access.SharedSecrets;
import sun.security.util.SecurityConstants;
import sun.security.action.GetPropertyAction;

/**
 * Class {@code 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:
 * <a href=
 * "http://web.archive.org/web/20051219043731/http://archive.ncsa.uiuc.edu/SDG/Software/Mosaic/Demo/url-primer.html">
 * <i>Types of URL</i></a>
 * <p>
 * In general, a URL can be broken into several parts. Consider the
 * following example:
 * <blockquote><pre>
 * http://www.example.com/docs/resource1.html
 * </pre></blockquote>
 * <p>
 * The URL above indicates that the protocol to use is
 * {@code http} (HyperText Transfer Protocol) and that the
 * information resides on a host machine named
 * {@code www.example.com}. The information on that host
 * machine is named {@code /docs/resource1.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 <i>path</i> component.
 * <p>
 * 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
 * {@code http} is {@code 80}. An alternative port could be
 * specified as:
 * <blockquote><pre>
 * http://www.example.com:1080/docs/resource1.html
 * </pre></blockquote>
 * <p>
 * The syntax of {@code URL} is defined by <a
 * href="http://www.ietf.org/rfc/rfc2396.txt"><i>RFC&nbsp;2396: Uniform
 * Resource Identifiers (URI): Generic Syntax</i></a>, amended by <a
 * href="http://www.ietf.org/rfc/rfc2732.txt"><i>RFC&nbsp;2732: Format for
 * Literal IPv6 Addresses in URLs</i></a>. The Literal IPv6 address format
 * also supports scope_ids. The syntax and usage of scope_ids is described
 * <a href="Inet6Address.html#scoped">here</a>.
 * <p>
 * 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,
 * <blockquote><pre>
 * http://www.example.com/index.html#chapter1
 * </pre></blockquote>
 * <p>
 * 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 {@code chapter1} attached to it. The
 * meaning of a tag is resource specific.
 * <p>
 * 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:
 * <blockquote><pre>
 * http://www.example.com/index.html
 * </pre></blockquote>
 * contained within it the relative URL:
 * <blockquote><pre>
 * FAQ.html
 * </pre></blockquote>
 * it would be a shorthand for:
 * <blockquote><pre>
 * http://www.example.com/FAQ.html
 * </pre></blockquote>
 * <p>
 * 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.
 * <p>
 * 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:<br>
 * <pre> http://foo.com/hello world/ and http://foo.com/hello%20world</pre>
 * would be considered not equal to each other.
 * <p>
 * Note, the {@link java.net.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 {@link java.net.URI},
 * and to convert between these two classes using {@link #toURI()} and
 * {@link URI#toURL()}.
 * <p>
 * The {@link URLEncoder} and {@link URLDecoder} classes can also be
 * used, but only for HTML form encoding, which is not the same
 * as the encoding scheme defined in RFC2396.
 *
 * @apiNote
 *
 * Applications working with file paths and file URIs should take great
 * care to use the appropriate methods to convert between the two.
 * The {@link Path#of(URI)} factory method and the {@link File#File(URI)}
 * constructor can be used to create {@link Path} or {@link File}
 * objects from a file URI. {@link Path#toUri()} and {@link File#toURI()}
 * can be used to create a {@link URI} from a file path, which can be
 * converted to URL using {@link URI#toURL()}.
 * Applications should never try to {@linkplain #URL(String, String, String)
 * construct} or {@linkplain #URL(String) parse} a {@code URL}
 * from the direct string representation of a {@code File} or {@code Path}
 * instance.
 * <p>
 * Some components of a URL or URI, such as <i>userinfo</i>, may
 * be abused to construct misleading URLs or URIs. Applications
 * that deal with URLs or URIs should take into account
 * the recommendations advised in <a
 * href="https://tools.ietf.org/html/rfc3986#section-7">RFC3986,
 * Section 7, Security Considerations</a>.
 *
 * @author James Gosling
 * @since 1.0
 */
public final class URL implements java.io.Serializable {

 static final String BUILTIN_HANDLERS_PREFIX = "sun.net.www.protocol";
 static final long serialVersionUID = -7627629688361524110L;

 /**
 * The property which specifies the package prefix list to be scanned
 * for protocol handlers. The value of this property (if any) should
 * be a vertical bar delimited list of package names to search through
 * for a protocol handler to load. The policy of this class is that
 * all protocol handlers will be in a class called <protocolname>.Handler,
 * and each package in the list is examined in turn for a matching
 * handler. If none are found (or the property is not specified), the
 * default package prefix, sun.net.www.protocol, is used. The search
 * proceeds from the first package in the list to the last and stops
 * when a match is found.
 */
 private static final String protocolPathProp = "java.protocol.handler.pkgs";

 /**
 * The protocol to use (ftp, http, nntp, ... etc.) .
 * @serial
 */
 private String protocol;

 /**
 * The host name to connect to.
 * @serial
 */
 private String host;

 /**
 * The protocol port to connect to.
 * @serial
 */
 private int port = -1;

 /**
 * The specified file name on that host. {@code file} is
 * defined as {@code path[?query]}
 * @serial
 */
 private String file;

 /**
 * The query part of this URL.
 */
 private transient String query;

 /**
 * The authority part of this URL.
 * @serial
 */
 private String authority;

 /**
 * The path part of this URL.
 */
 private transient String path;

 /**
 * The userinfo part of this URL.
 */
 private transient String userInfo;

 /**
 * # reference.
 * @serial
 */
 private String ref;

 /**
 * The host's IP address, used in equals and hashCode.
 * Computed on demand. An uninitialized or unknown hostAddress is null.
 */
 transient InetAddress hostAddress;

 /**
 * The URLStreamHandler for this URL.
 */
 transient URLStreamHandler handler;

 /* Our hash code.
 * @serial
 */
 private int hashCode = -1;

 private transient UrlDeserializedState tempState;

 /**
 * Creates a {@code URL} object from the specified
 * {@code protocol}, {@code host}, {@code port}
 * number, and {@code file}.<p>
 *
 * {@code host} can be expressed as a host name or a literal
 * IP address. If IPv6 literal address is used, it should be
 * enclosed in square brackets ({@code '['} and {@code ']'}), as
 * specified by <a
 * href="http://www.ietf.org/rfc/rfc2732.txt">RFC&nbsp;2732</a>;
 * However, the literal IPv6 address format defined in <a
 * href="http://www.ietf.org/rfc/rfc2373.txt"><i>RFC&nbsp;2373: IP
 * Version 6 Addressing Architecture</i></a> is also accepted.<p>
 *
 * Specifying a {@code port} number of {@code -1}
 * indicates that the URL should use the default port for the
 * protocol.<p>
 *
 * If this is the first URL object being created with the specified
 * protocol, a <i>stream protocol handler</i> object, an instance of
 * class {@code URLStreamHandler}, is created for that protocol:
 * <ol>
 * <li>If the application has previously set up an instance of
 * {@code URLStreamHandlerFactory} as the stream handler factory,
 * then the {@code createURLStreamHandler} method of that instance
 * is called with the protocol string as an argument to create the
 * stream protocol handler.
 * <li>If no {@code URLStreamHandlerFactory} has yet been set up,
 * or if the factory's {@code createURLStreamHandler} method
 * returns {@code null}, then the {@linkplain java.util.ServiceLoader
 * ServiceLoader} mechanism is used to locate {@linkplain
 * java.net.spi.URLStreamHandlerProvider URLStreamHandlerProvider}
 * implementations using the system class
 * loader. The order that providers are located is implementation
 * specific, and an implementation is free to cache the located
 * providers. A {@linkplain java.util.ServiceConfigurationError
 * ServiceConfigurationError}, {@code Error} or {@code RuntimeException}
 * thrown from the {@code createURLStreamHandler}, if encountered, will
 * be propagated to the calling thread. The {@code
 * createURLStreamHandler} method of each provider, if instantiated, is
 * invoked, with the protocol string, until a provider returns non-null,
 * or all providers have been exhausted.
 * <li>If the previous step fails to find a protocol handler, the
 * constructor reads the value of the system property:
 * <blockquote>{@systemProperty
 * java.protocol.handler.pkgs
 * }</blockquote>
 * If the value of that system property is not {@code null},
 * it is interpreted as a list of packages separated by a vertical
 * slash character '{@code |}'. The constructor tries to load
 * the class named:
 * <blockquote>{@code
 * <package>.<protocol>.Handler
 * }</blockquote>
 * where {@code <package>} is replaced by the name of the package
 * and {@code <protocol>} is replaced by the name of the protocol.
 * If this class does not exist, or if the class exists but it is not
 * a subclass of {@code URLStreamHandler}, then the next package
 * in the list is tried.
 * <li>If the previous step fails to find a protocol handler, then the
 * constructor tries to load a built-in protocol handler.
 * If this class does not exist, or if the class exists but it is not a
 * subclass of {@code URLStreamHandler}, then a
 * {@code MalformedURLException} is thrown.
 * </ol>
 *
 * <p>Protocol handlers for the following protocols are guaranteed
 * to exist on the search path :-
 * <blockquote><pre>
 * http, https, file, and jar
 * </pre></blockquote>
 * Protocol handlers for additional protocols may also be available.
 * Some protocol handlers, for example those used for loading platform
 * classes or classes on the class path, may not be overridden. The details
 * of such restrictions, and when those restrictions apply (during
 * initialization of the runtime for example), are implementation specific
 * and therefore not specified
 *
 * <p>No validation of the inputs is performed by this constructor.
 *
 * @param protocol the name of the protocol to use.
 * @param host the name of the host.
 * @param port the port number on the host.
 * @param file the file on the host
 * @exception MalformedURLException if an unknown protocol or the port
 * is a negative number other than -1
 * @see java.lang.System#getProperty(java.lang.String)
 * @see java.net.URL#setURLStreamHandlerFactory(
 * java.net.URLStreamHandlerFactory)
 * @see java.net.URLStreamHandler
 * @see java.net.URLStreamHandlerFactory#createURLStreamHandler(
 * java.lang.String)
 */
 public URL(String protocol, String host, int port, String file)
 throws MalformedURLException
 {
 this(protocol, host, port, file, null);
 }

 /**
 * Creates a URL from the specified {@code protocol}
 * name, {@code host} name, and {@code file} name. The
 * default port for the specified protocol is used.
 * <p>
 * This constructor is equivalent to the four-argument
 * constructor with the only difference of using the
 * default port for the specified protocol.
 *
 * No validation of the inputs is performed by this constructor.
 *
 * @param protocol the name of the protocol to use.
 * @param host the name of the host.
 * @param file the file on the host.
 * @exception MalformedURLException if an unknown protocol is specified.
 * @see java.net.URL#URL(java.lang.String, java.lang.String,
 * int, java.lang.String)
 */
 public URL(String protocol, String host, String file)
 throws MalformedURLException {
 this(protocol, host, -1, file);
 }

 /**
 * Creates a {@code URL} object from the specified
 * {@code protocol}, {@code host}, {@code port}
 * number, {@code file}, and {@code handler}. Specifying
 * a {@code port} number of {@code -1} indicates that
 * the URL should use the default port for the protocol. Specifying
 * a {@code handler} of {@code null} indicates that the URL
 * should use a default stream handler for the protocol, as outlined
 * for:
 * java.net.URL#URL(java.lang.String, java.lang.String, int,
 * java.lang.String)
 *
 * <p>If the handler is not null and there is a security manager,
 * the security manager's {@code checkPermission}
 * method is called with a
 * {@code NetPermission("specifyStreamHandler")} permission.
 * This may result in a SecurityException.
 *
 * No validation of the inputs is performed by this constructor.
 *
 * @param protocol the name of the protocol to use.
 * @param host the name of the host.
 * @param port the port number on the host.
 * @param file the file on the host
 * @param handler the stream handler for the URL.
 * @exception MalformedURLException if an unknown protocol or the port
 is a negative number other than -1
 * @exception SecurityException
 * if a security manager exists and its
 * {@code checkPermission} method doesn't allow
 * specifying a stream handler explicitly.
 * @see java.lang.System#getProperty(java.lang.String)
 * @see java.net.URL#setURLStreamHandlerFactory(
 * java.net.URLStreamHandlerFactory)
 * @see java.net.URLStreamHandler
 * @see java.net.URLStreamHandlerFactory#createURLStreamHandler(
 * java.lang.String)
 * @see SecurityManager#checkPermission
 * @see java.net.NetPermission
 */
 public URL(String protocol, String host, int port, String file,
 URLStreamHandler handler) throws MalformedURLException {
 if (handler != null) {
 SecurityManager sm = System.getSecurityManager();
 if (sm != null) {
 // check for permission to specify a handler
 checkSpecifyHandler(sm);
 }
 }

 protocol = toLowerCase(protocol);
 this.protocol = protocol;
 if (host != null) {

 /**
 * if host is a literal IPv6 address,
 * we will make it conform to RFC 2732
 */
 if (host.indexOf(':') >= 0 && !host.startsWith("[")) {
 host = "["+host+"]";
 }
 this.host = host;

 if (port < -1) {
 throw new MalformedURLException("Invalid port number :" +
 port);
 }
 this.port = port;
 authority = (port == -1) ? host : host + ":" + port;
 }

 int index = file.indexOf('#');
 this.ref = index < 0 ? null : file.substring(index + 1);
 file = index < 0 ? file : file.substring(0, index);
 int q = file.lastIndexOf('?');
 if (q != -1) {
 this.query = file.substring(q + 1);
 this.path = file.substring(0, q);
 this.file = path + "?" + query;
 } else {
 this.path = file;
 this.file = path;
 }

 // Note: we don't do validation of the URL here. Too risky to change
 // right now, but worth considering for future reference. -br
 if (handler == null &&
 (handler = getURLStreamHandler(protocol)) == null) {
 throw new MalformedURLException("unknown protocol: " + protocol);
 }
 this.handler = handler;
 }

 /**
 * Creates a {@code URL} object from the {@code String}
 * representation.
 * <p>
 * This constructor is equivalent to a call to the two-argument
 * constructor with a {@code null} first argument.
 *
 * @param spec the {@code String} to parse as a URL.
 * @exception MalformedURLException if no protocol is specified, or an
 * unknown protocol is found, or {@code spec} is {@code null},
 * or the parsed URL fails to comply with the specific syntax
 * of the associated protocol.
 * @see java.net.URL#URL(java.net.URL, java.lang.String)
 */
 public URL(String spec) throws MalformedURLException {
 this(null, 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 &quot;Uniform Resource Identifiers : Generic * Syntax&quot; :
 * <blockquote><pre>
 * &lt;scheme&gt;://&lt;authority&gt;&lt;path&gt;?&lt;query&gt;#&lt;fragment&gt;
 * </pre></blockquote>
 * 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.
 * <p>
 * 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.
 * <p>
 * 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.
 * <p>
 * If the spec's path component begins with a slash character
 * &quot;/&quot; then the
 * path is treated as absolute and the spec path replaces the context path.
 * <p>
 * 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 &quot;..&quot; and &quot;.&quot;.
 * <p>
 * For a more detailed description of URL parsing, refer to RFC2396.
 *
 * @param context the context in which to parse the specification.
 * @param spec the {@code String} to parse as a URL.
 * @exception MalformedURLException if no protocol is specified, or an
 * unknown protocol is found, or {@code spec} is {@code null},
 * or the parsed URL fails to comply with the specific syntax
 * of the associated protocol.
 * @see java.net.URL#URL(java.lang.String, java.lang.String,
 * int, java.lang.String)
 * @see java.net.URLStreamHandler
 * @see java.net.URLStreamHandler#parseURL(java.net.URL,
 * java.lang.String, int, int)
 */
 public URL(URL context, String spec) throws MalformedURLException {
 this(context, spec, null);
 }

 /**
 * 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.
 *
 * @param context the context in which to parse the specification.
 * @param spec the {@code String} to parse as a URL.
 * @param handler the stream handler for the URL.
 * @exception MalformedURLException if no protocol is specified, or an
 * unknown protocol is found, or {@code spec} is {@code null},
 * or the parsed URL fails to comply with the specific syntax
 * of the associated protocol.
 * @exception SecurityException
 * if a security manager exists and its
 * {@code checkPermission} method doesn't allow
 * specifying a stream handler.
 * @see java.net.URL#URL(java.lang.String, java.lang.String,
 * int, java.lang.String)
 * @see java.net.URLStreamHandler
 * @see java.net.URLStreamHandler#parseURL(java.net.URL,
 * java.lang.String, int, int)
 */
 public URL(URL context, String spec, URLStreamHandler handler)
 throws MalformedURLException
 {
 String original = spec;
 int i, limit, c;
 int start = 0;
 String newProtocol = null;
 boolean aRef=false;
 boolean isRelative = false;

 // Check for permission to specify a handler
 if (handler != null) {
 SecurityManager sm = System.getSecurityManager();
 if (sm != null) {
 checkSpecifyHandler(sm);
 }
 }

 try {
 limit = spec.length();
 while ((limit > 0) && (spec.charAt(limit - 1) <= ' ')) {
 limit--; //eliminate trailing whitespace
 }
 while ((start < limit) && (spec.charAt(start) <= ' ')) {
 start++; // eliminate leading whitespace
 }

 if (spec.regionMatches(true, start, "url:", 0, 4)) {
 start += 4;
 }
 if (start < spec.length() && spec.charAt(start) == '#') {
 /* we're assuming this is a ref relative to the context URL.
 * This means protocols cannot start w/ '#', but we must parse
 * ref URL's like: "hello:there" w/ a ':' in them.
 */
 aRef=true;
 }
 for (i = start ; !aRef && (i < limit) &&
 ((c = spec.charAt(i)) != '/') ; i++) {
 if (c == ':') {
 String s = toLowerCase(spec.substring(start, i));
 if (isValidProtocol(s)) {
 newProtocol = s;
 start = i + 1;
 }
 break;
 }
 }

 // Only use our context if the protocols match.
 protocol = newProtocol;
 if ((context != null) && ((newProtocol == null) ||
 newProtocol.equalsIgnoreCase(context.protocol))) {
 // inherit the protocol handler from the context
 // if not specified to the constructor
 if (handler == null) {
 handler = context.handler;
 }

 // If the context is a hierarchical URL scheme and the spec
 // contains a matching scheme then maintain backwards
 // compatibility and treat it as if the spec didn't contain
 // the scheme; see 5.2.3 of RFC2396
 if (context.path != null && context.path.startsWith("/"))
 newProtocol = null;

 if (newProtocol == null) {
 protocol = context.protocol;
 authority = context.authority;
 userInfo = context.userInfo;
 host = context.host;
 port = context.port;
 file = context.file;
 path = context.path;
 isRelative = true;
 }
 }

 if (protocol == null) {
 throw new MalformedURLException("no protocol: "+original);
 }

 // Get the protocol handler if not specified or the protocol
 // of the context could not be used
 if (handler == null &&
 (handler = getURLStreamHandler(protocol)) == null) {
 throw new MalformedURLException("unknown protocol: "+protocol);
 }

 this.handler = handler;

 i = spec.indexOf('#', start);
 if (i >= 0) {
 ref = spec.substring(i + 1, limit);
 limit = i;
 }

 /*
 * Handle special case inheritance of query and fragment
 * implied by RFC2396 section 5.2.2.
 */
 if (isRelative && start == limit) {
 query = context.query;
 if (ref == null) {
 ref = context.ref;
 }
 }

 handler.parseURL(this, spec, start, limit);

 } catch(MalformedURLException e) {
 throw e;
 } catch(Exception e) {
 MalformedURLException exception = new MalformedURLException(e.getMessage());
 exception.initCause(e);
 throw exception;
 }
 }

 /**
 * Creates a URL from a URI, as if by invoking {@code uri.toURL()}.
 *
 * @see java.net.URI#toURL()
 */
 static URL fromURI(URI uri) throws MalformedURLException {
 if (!uri.isAbsolute()) {
 throw new IllegalArgumentException("URI is not absolute");
 }
 String protocol = uri.getScheme();

 // In general we need to go via Handler.parseURL, but for the jrt
 // protocol we enforce that the Handler is not overrideable and can
 // optimize URI to URL conversion.
 //
 // Case-sensitive comparison for performance; malformed protocols will
 // be handled correctly by the slow path.
 if (protocol.equals("jrt") && !uri.isOpaque()
 && uri.getRawFragment() == null) {

 String query = uri.getRawQuery();
 String path = uri.getRawPath();
 String file = (query == null) ? path : path + "?" + query;

 // URL represent undefined host as empty string while URI use null
 String host = uri.getHost();
 if (host == null) {
 host = "";
 }

 int port = uri.getPort();

 return new URL("jrt", host, port, file, null);
 } else {
 return new URL((URL)null, uri.toString(), null);
 }
 }

 /*
 * Returns true if specified string is a valid protocol name.
 */
 private boolean isValidProtocol(String protocol) {
 int len = protocol.length();
 if (len < 1)
 return false;
 char c = protocol.charAt(0);
 if (!Character.isLetter(c))
 return false;
 for (int i = 1; i < len; i++) {
 c = protocol.charAt(i);
 if (!Character.isLetterOrDigit(c) && c != '.' && c != '+' &&
 c != '-') {
 return false;
 }
 }
 return true;
 }

 /*
 * Checks for permission to specify a stream handler.
 */
 private void checkSpecifyHandler(SecurityManager sm) {
 sm.checkPermission(SecurityConstants.SPECIFY_HANDLER_PERMISSION);
 }

 /**
 * Sets the fields of the URL. This is not a public method so that
 * only URLStreamHandlers can modify URL fields. URLs are
 * otherwise constant.
 *
 * @param protocol the name of the protocol to use
 * @param host the name of the host
 @param port the port number on the host
 * @param file the file on the host
 * @param ref the internal reference in the URL
 */
 void set(String protocol, String host, int port,
 String file, String ref) {
 synchronized (this) {
 this.protocol = protocol;
 this.host = host;
 authority = port == -1 ? host : host + ":" + port;
 this.port = port;
 this.file = file;
 this.ref = ref;
 /* This is very important. We must recompute this after the
 * URL has been changed. */
 hashCode = -1;
 hostAddress = null;
 int q = file.lastIndexOf('?');
 if (q != -1) {
 query = file.substring(q+1);
 path = file.substring(0, q);
 } else
 path = file;
 }
 }

 /**
 * Sets the specified 8 fields of the URL. This is not a public method so
 * that only URLStreamHandlers can modify URL fields. URLs are otherwise
 * constant.
 *
 * @param protocol the name of the protocol to use
 * @param host the name of the host
 * @param port the port number on the host
 * @param authority the authority part for the url
 * @param userInfo the username and password
 * @param path the file on the host
 * @param ref the internal reference in the URL
 * @param query the query part of this URL
 * @since 1.3
 */
 void set(String protocol, String host, int port,
 String authority, String userInfo, String path,
 String query, String ref) {
 synchronized (this) {
 this.protocol = protocol;
 this.host = host;
 this.port = port;
 this.file = query == null ? path : path + "?" + query;
 this.userInfo = userInfo;
 this.path = path;
 this.ref = ref;
 /* This is very important. We must recompute this after the
 * URL has been changed. */
 hashCode = -1;
 hostAddress = null;
 this.query = query;
 this.authority = authority;
 }
 }

 /**
 * Gets the query part of this {@code URL}.
 *
 * @return the query part of this {@code URL},
 * or <CODE>null</CODE> if one does not exist
 * @since 1.3
 */
 public String getQuery() {
 return query;
 }

 /**
 * Gets the path part of this {@code URL}.
 *
 * @return the path part of this {@code URL}, or an
 * empty string if one does not exist
 * @since 1.3
 */
 public String getPath() {
 return path;
 }

 /**
 * Gets the userInfo part of this {@code URL}.
 *
 * @return the userInfo part of this {@code URL}, or
 * <CODE>null</CODE> if one does not exist
 * @since 1.3
 */
 public String getUserInfo() {
 return userInfo;
 }

 /**
 * Gets the authority part of this {@code URL}.
 *
 * @return the authority part of this {@code URL}
 * @since 1.3
 */
 public String getAuthority() {
 return authority;
 }

 /**
 * Gets the port number of this {@code URL}.
 *
 * @return the port number, or -1 if the port is not set
 */
 public int getPort() {
 return port;
 }

 /**
 * Gets the default port number of the protocol associated
 * with this {@code URL}. If the URL scheme or the URLStreamHandler
 * for the URL do not define a default port number,
 * then -1 is returned.
 *
 * @return the port number
 * @since 1.4
 */
 public int getDefaultPort() {
 return handler.getDefaultPort();
 }

 /**
 * Gets the protocol name of this {@code URL}.
 *
 * @return the protocol of this {@code URL}.
 */
 public String getProtocol() {
 return protocol;
 }

 /**
 * Gets the host name of this {@code 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 ({@code '['} and {@code ']'}).
 *
 * @return the host name of this {@code URL}.
 */
 public String getHost() {
 return host;
 }

 /**
 * Gets the file name of this {@code URL}.
 * The returned file portion will be
 * the same as <CODE>getPath()</CODE>, plus the concatenation of
 * the value of <CODE>getQuery()</CODE>, if any. If there is
 * no query portion, this method and <CODE>getPath()</CODE> will
 * return identical results.
 *
 * @return the file name of this {@code URL},
 * or an empty string if one does not exist
 */
 public String getFile() {
 return file;
 }

 /**
 * Gets the anchor (also known as the "reference") of this
 * {@code URL}.
 *
 * @return the anchor (also known as the "reference") of this
 * {@code URL}, or <CODE>null</CODE> if one does not exist
 */
 public String getRef() {
 return ref;
 }

 /**
 * Compares this URL for equality with another object.<p>
 *
 * If the given object is not a URL then this method immediately returns
 * {@code false}.<p>
 *
 * 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.<p>
 *
 * 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 null.<p>
 *
 * Since hosts comparison requires name resolution, this operation is a
 * blocking operation. <p>
 *
 * Note: The defined behavior for {@code equals} is known to
 * be inconsistent with virtual hosting in HTTP.
 *
 * @param obj the URL to compare against.
 * @return {@code true} if the objects are the same;
 * {@code false} otherwise.
 */
 public boolean equals(Object obj) {
 if (!(obj instanceof URL))
 return false;
 URL u2 = (URL)obj;

 return handler.equals(this, u2);
 }

 /**
 * Creates an integer suitable for hash table indexing.<p>
 *
 * The hash code is based upon all the URL components relevant for URL
 * comparison. As such, this operation is a blocking operation.
 *
 * @return a hash code for this {@code URL}.
 */
 public synchronized int hashCode() {
 if (hashCode != -1)
 return hashCode;

 hashCode = handler.hashCode(this);
 return hashCode;
 }

 /**
 * Compares two URLs, excluding the fragment component.<p>
 *
 * Returns {@code true} if this {@code URL} and the
 * {@code other} argument are equal without taking the
 * fragment component into consideration.
 *
 * @param other the {@code URL} to compare against.
 * @return {@code true} if they reference the same remote object;
 * {@code false} otherwise.
 */
 public boolean sameFile(URL other) {
 return handler.sameFile(this, other);
 }

 /**
 * Constructs a string representation of this {@code URL}. The
 * string is created by calling the {@code toExternalForm}
 * method of the stream protocol handler for this object.
 *
 * @return a string representation of this object.
 * @see java.net.URL#URL(java.lang.String, java.lang.String, int,
 * java.lang.String)
 * @see java.net.URLStreamHandler#toExternalForm(java.net.URL)
 */
 public String toString() {
 return toExternalForm();
 }

 /**
 * Constructs a string representation of this {@code URL}. The
 * string is created by calling the {@code toExternalForm}
 * method of the stream protocol handler for this object.
 *
 * @return a string representation of this object.
 * @see java.net.URL#URL(java.lang.String, java.lang.String,
 * int, java.lang.String)
 * @see java.net.URLStreamHandler#toExternalForm(java.net.URL)
 */
 public String toExternalForm() {
 return handler.toExternalForm(this);
 }

 /**
 * Returns a {@link java.net.URI} equivalent to this URL.
 * This method functions in the same way as {@code new URI (this.toString())}.
 * <p>Note, any URL instance that complies with RFC 2396 can be converted
 * to a URI. However, some URLs that are not strictly in compliance
 * can not be converted to a URI.
 *
 * @exception URISyntaxException if this URL is not formatted strictly according to
 * RFC2396 and cannot be converted to a URI.
 *
 * @return a URI instance equivalent to this URL.
 * @since 1.5
 */
 public URI toURI() throws URISyntaxException {
 return new URI (toString());
 }

 /**
 * Returns a {@link java.net.URLConnection URLConnection} instance that
 * represents a connection to the remote object referred to by the
 * {@code URL}.
 *
 * <P>A new instance of {@linkplain java.net.URLConnection URLConnection} is
 * created every time when invoking the
 * {@linkplain java.net.URLStreamHandler#openConnection(URL)
 * URLStreamHandler.openConnection(URL)} method of the protocol handler for
 * this URL.</P>
 *
 * <P>It should be noted that a URLConnection instance does not establish
 * the actual network connection on creation. This will happen only when
 * calling {@linkplain java.net.URLConnection#connect() URLConnection.connect()}.</P>
 *
 * <P>If for the URL'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.</P>
 *
 * @return a {@link java.net.URLConnection URLConnection} linking
 * to the URL.
 * @exception IOException if an I/O exception occurs.
 * @see java.net.URL#URL(java.lang.String, java.lang.String,
 * int, java.lang.String)
 */
 public URLConnection openConnection() throws java.io.IOException {
 return handler.openConnection(this);
 }

 /**
 * Same as {@link #openConnection()}, 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.
 *
 * Invoking this method preempts the system's default
 * {@link java.net.ProxySelector ProxySelector} settings.
 *
 * @param proxy the Proxy through which this connection
 * will be made. If direct connection is desired,
 * Proxy.NO_PROXY should be specified.
 * @return a {@code URLConnection} to the URL.
 * @exception IOException if an I/O exception occurs.
 * @exception SecurityException if a security manager is present
 * and the caller doesn't have permission to connect
 * to the proxy.
 * @exception IllegalArgumentException will be thrown if proxy is null,
 * or proxy has the wrong type
 * @exception UnsupportedOperationException if the subclass that
 * implements the protocol handler doesn't support
 * this method.
 * @see java.net.URL#URL(java.lang.String, java.lang.String,
 * int, java.lang.String)
 * @see java.net.URLConnection
 * @see java.net.URLStreamHandler#openConnection(java.net.URL,
 * java.net.Proxy)
 * @since 1.5
 */
 public URLConnection openConnection(Proxy proxy)
 throws java.io.IOException {
 if (proxy == null) {
 throw new IllegalArgumentException("proxy can not be null");
 }

 // Create a copy of Proxy as a security measure
 Proxy p = proxy == Proxy.NO_PROXY ? Proxy.NO_PROXY : sun.net.ApplicationProxy.create(proxy);
 SecurityManager sm = System.getSecurityManager();
 if (p.type() != Proxy.Type.DIRECT && sm != null) {
 InetSocketAddress epoint = (InetSocketAddress) p.address();
 if (epoint.isUnresolved())
 sm.checkConnect(epoint.getHostName(), epoint.getPort());
 else
 sm.checkConnect(epoint.getAddress().getHostAddress(),
 epoint.getPort());
 }
 return handler.openConnection(this, p);
 }

 /**
 * Opens a connection to this {@code URL} and returns an
 * {@code InputStream} for reading from that connection. This
 * method is a shorthand for:
 * <blockquote><pre>
 * openConnection().getInputStream()
 * </pre></blockquote>
 *
 * @return an input stream for reading from the URL connection.
 * @exception IOException if an I/O exception occurs.
 * @see java.net.URL#openConnection()
 * @see java.net.URLConnection#getInputStream()
 */
 public final InputStream openStream() throws java.io.IOException {
 return openConnection().getInputStream();
 }

 /**
 * Gets the contents of this URL. This method is a shorthand for:
 * <blockquote><pre>
 * openConnection().getContent()
 * </pre></blockquote>
 *
 * @return the contents of this URL.
 * @exception IOException if an I/O exception occurs.
 * @see java.net.URLConnection#getContent()
 */
 public final Object getContent() throws java.io.IOException {
 return openConnection().getContent();
 }

 /**
 * Gets the contents of this URL. This method is a shorthand for:
 * <blockquote><pre>
 * openConnection().getContent(classes)
 * </pre></blockquote>
 *
 * @param classes an array of Java types
 * @return the content object of this URL that is the first match of
 * the types specified in the classes array.
 * null if none of the requested types are supported.
 * @exception IOException if an I/O exception occurs.
 * @see java.net.URLConnection#getContent(Class[])
 * @since 1.3
 */
 public final Object getContent(Class<?>[] classes)
 throws java.io.IOException {
 return openConnection().getContent(classes);
 }

 /**
 * The URLStreamHandler factory.
 */
 private static volatile URLStreamHandlerFactory factory;

 /**
 * Sets an application's {@code URLStreamHandlerFactory}.
 * This method can be called at most once in a given Java Virtual
 * Machine.
 *
 *<p> The {@code URLStreamHandlerFactory} instance is used to
 *construct a stream protocol handler from a protocol name.
 *
 * <p> If there is a security manager, this method first calls
 * the security manager's {@code checkSetFactory} method
 * to ensure the operation is allowed.
 * This could result in a SecurityException.
 *
 * @param fac the desired factory.
 * @exception Error if the application has already set a factory.
 * @exception SecurityException if a security manager exists and its
 * {@code checkSetFactory} method doesn't allow
 * the operation.
 * @see java.net.URL#URL(java.lang.String, java.lang.String,
 * int, java.lang.String)
 * @see java.net.URLStreamHandlerFactory
 * @see SecurityManager#checkSetFactory
 */
 public static void setURLStreamHandlerFactory(URLStreamHandlerFactory fac) {
 synchronized (streamHandlerLock) {
 if (factory != null) {
 throw new Error("factory already defined");
 }
 SecurityManager security = System.getSecurityManager();
 if (security != null) {
 security.checkSetFactory();
 }
 handlers.clear();

 // safe publication of URLStreamHandlerFactory with volatile write
 factory = fac;
 }
 }

 private static final URLStreamHandlerFactory defaultFactory = new DefaultFactory();

 private static class DefaultFactory implements URLStreamHandlerFactory {
 private static String PREFIX = "sun.net.www.protocol";

 public URLStreamHandler createURLStreamHandler(String protocol) {
 String name = PREFIX + "." + protocol + ".Handler";
 try {
 @SuppressWarnings("deprecation")
 Object o = Class.forName(name).newInstance();
 return (URLStreamHandler)o;
 } catch (ClassNotFoundException x) {
 // ignore
 } catch (Exception e) {
 // For compatibility, all Exceptions are ignored.
 // any number of exceptions can get thrown here
 }
 return null;
 }
 }

 private static URLStreamHandler lookupViaProperty(String protocol) {
 String packagePrefixList =
 GetPropertyAction.privilegedGetProperty(protocolPathProp);
 if (packagePrefixList == null) {
 // not set
 return null;
 }

 String[] packagePrefixes = packagePrefixList.split("\\|");
 URLStreamHandler handler = null;
 for (int i=0; handler == null && i<packagePrefixes.length; i++) {
 String packagePrefix = packagePrefixes[i].trim();
 try {
 String clsName = packagePrefix + "." + protocol + ".Handler";
 Class<?> cls = null;
 try {
 cls = Class.forName(clsName);
 } catch (ClassNotFoundException e) {
 ClassLoader cl = ClassLoader.getSystemClassLoader();
 if (cl != null) {
 cls = cl.loadClass(clsName);
 }
 }
 if (cls != null) {
 @SuppressWarnings("deprecation")
 Object tmp = cls.newInstance();
 handler = (URLStreamHandler)tmp;
 }
 } catch (Exception e) {
 // any number of exceptions can get thrown here
 }
 }
 return handler;
 }

 private static Iterator<URLStreamHandlerProvider> providers() {
 return new Iterator<>() {

 ClassLoader cl = ClassLoader.getSystemClassLoader();
 ServiceLoader<URLStreamHandlerProvider> sl =
 ServiceLoader.load(URLStreamHandlerProvider.class, cl);
 Iterator<URLStreamHandlerProvider> i = sl.iterator();

 URLStreamHandlerProvider next = null;

 private boolean getNext() {
 while (next == null) {
 try {
 if (!i.hasNext())
 return false;
 next = i.next();
 } catch (ServiceConfigurationError sce) {
 if (sce.getCause() instanceof SecurityException) {
 // Ignore security exceptions
 continue;
 }
 throw sce;
 }
 }
 return true;
 }

 public boolean hasNext() {
 return getNext();
 }

 public URLStreamHandlerProvider next() {
 if (!getNext())
 throw new NoSuchElementException();
 URLStreamHandlerProvider n = next;
 next = null;
 return n;
 }
 };
 }

 // Thread-local gate to prevent recursive provider lookups
 private static ThreadLocal<Object> gate = new ThreadLocal<>();

 private static URLStreamHandler lookupViaProviders(final String protocol) {
 if (gate.get() != null)
 throw new Error("Circular loading of URL stream handler providers detected");

 gate.set(gate);
 try {
 return AccessController.doPrivileged(
 new PrivilegedAction<>() {
 public URLStreamHandler run() {
 Iterator<URLStreamHandlerProvider> itr = providers();
 while (itr.hasNext()) {
 URLStreamHandlerProvider f = itr.next();
 URLStreamHandler h = f.createURLStreamHandler(protocol);
 if (h != null)
 return h;
 }
 return null;
 }
 });
 } finally {
 gate.set(null);
 }
 }

 /**
 * Returns the protocol in lower case. Special cases known protocols
 * to avoid loading locale classes during startup.
 */
 static String toLowerCase(String protocol) {
 if (protocol.equals("jrt") || protocol.equals("file") || protocol.equals("jar")) {
 return protocol;
 } else {
 return protocol.toLowerCase(Locale.ROOT);
 }
 }

 /**
 * Non-overrideable protocols: "jrt" and "file"
 *
 * Character-based comparison for performance reasons; also ensures
 * case-insensitive comparison in a locale-independent fashion.
 */
 static boolean isOverrideable(String protocol) {
 if (protocol.length() == 3) {
 if ((Character.toLowerCase(protocol.charAt(0)) == 'j') &&
 (Character.toLowerCase(protocol.charAt(1)) == 'r') &&
 (Character.toLowerCase(protocol.charAt(2)) == 't')) {
 return false;
 }
 } else if (protocol.length() == 4) {
 if ((Character.toLowerCase(protocol.charAt(0)) == 'f') &&
 (Character.toLowerCase(protocol.charAt(1)) == 'i') &&
 (Character.toLowerCase(protocol.charAt(2)) == 'l') &&
 (Character.toLowerCase(protocol.charAt(3)) == 'e')) {
 return false;
 }
 }
 return true;
 }

 /**
 * A table of protocol handlers.
 */
 static Hashtable<String,URLStreamHandler> handlers = new Hashtable<>();
 private static final Object streamHandlerLock = new Object();

 /**
 * Returns the Stream Handler.
 * @param protocol the protocol to use
 */
 static URLStreamHandler getURLStreamHandler(String protocol) {

 URLStreamHandler handler = handlers.get(protocol);

 if (handler != null) {
 return handler;
 }

 URLStreamHandlerFactory fac;
 boolean checkedWithFactory = false;

 if (isOverrideable(protocol) && jdk.internal.misc.VM.isBooted()) {
 // Use the factory (if any). Volatile read makes
 // URLStreamHandlerFactory appear fully initialized to current thread.
 fac = factory;
 if (fac != null) {
 handler = fac.createURLStreamHandler(protocol);
 checkedWithFactory = true;
 }

 if (handler == null && !protocol.equalsIgnoreCase("jar")) {
 handler = lookupViaProviders(protocol);
 }

 if (handler == null) {
 handler = lookupViaProperty(protocol);
 }
 }

 if (handler == null) {
 // Try the built-in protocol handler
 handler = defaultFactory.createURLStreamHandler(protocol);
 }

 synchronized (streamHandlerLock) {
 URLStreamHandler handler2 = null;

 // Check again with hashtable just in case another
 // thread created a handler since we last checked
 handler2 = handlers.get(protocol);

 if (handler2 != null) {
 return handler2;
 }

 // Check with factory if another thread set a
 // factory since our last check
 if (!checkedWithFactory && (fac = factory) != null) {
 handler2 = fac.createURLStreamHandler(protocol);
 }

 if (handler2 != null) {
 // The handler from the factory must be given more
 // importance. Discard the default handler that
 // this thread created.
 handler = handler2;
 }

 // Insert this handler into the hashtable
 if (handler != null) {
 handlers.put(protocol, handler);
 }
 }
 return handler;
 }

 /**
 * @serialField protocol String
 *
 * @serialField host String
 *
 * @serialField port int
 *
 * @serialField authority String
 *
 * @serialField file String
 *
 * @serialField ref String
 *
 * @serialField hashCode int
 *
 */
 private static final ObjectStreamField[] serialPersistentFields = {
 new ObjectStreamField("protocol", String.class),
 new ObjectStreamField("host", String.class),
 new ObjectStreamField("port", int.class),
 new ObjectStreamField("authority", String.class),
 new ObjectStreamField("file", String.class),
 new ObjectStreamField("ref", String.class),
 new ObjectStreamField("hashCode", int.class), };

 /**
 * WriteObject is called to save the state of the URL to an
 * ObjectOutputStream. The handler is not saved since it is
 * specific to this system.
 *
 * @serialData the default write object value. When read back in,
 * the reader must ensure that calling getURLStreamHandler with
 * the protocol variable returns a valid URLStreamHandler and
 * throw an IOException if it does not.
 */
 private synchronized void writeObject(java.io.ObjectOutputStream s)
 throws IOException
 {
 s.defaultWriteObject(); // write the fields
 }

 /**
 * readObject is called to restore the state of the URL from the
 * stream. It reads the components of the URL and finds the local
 * stream handler.
 */
 private synchronized void readObject(java.io.ObjectInputStream s)
 throws IOException, ClassNotFoundException {
 GetField gf = s.readFields();
 String protocol = (String)gf.get("protocol", null);
 if (getURLStreamHandler(protocol) == null) {
 throw new IOException("unknown protocol: " + protocol);
 }
 String host = (String)gf.get("host", null);
 int port = gf.get("port", -1);
 String authority = (String)gf.get("authority", null);
 String file = (String)gf.get("file", null);
 String ref = (String)gf.get("ref", null);
 int hashCode = gf.get("hashCode", -1);
 if (authority == null
 && ((host != null && !host.isEmpty()) || port != -1)) {
 if (host == null)
 host = "";
 authority = (port == -1) ? host : host + ":" + port;
 }
 tempState = new UrlDeserializedState(protocol, host, port, authority,
 file, ref, hashCode);
 }

 /**
 * Replaces the de-serialized object with an URL object.
 *
 * @return a newly created object from deserialized data
 *
 * @throws ObjectStreamException if a new object replacing this
 * object could not be created
 */

 private Object readResolve() throws ObjectStreamException {

 URLStreamHandler handler = null;
 // already been checked in readObject
 handler = getURLStreamHandler(tempState.getProtocol());

 URL replacementURL = null;
 if (isBuiltinStreamHandler(handler.getClass().getName())) {
 replacementURL = fabricateNewURL();
 } else {
 replacementURL = setDeserializedFields(handler);
 }
 return replacementURL;
 }

 private URL setDeserializedFields(URLStreamHandler handler) {
 URL replacementURL;
 String userInfo = null;
 String protocol = tempState.getProtocol();
 String host = tempState.getHost();
 int port = tempState.getPort();
 String authority = tempState.getAuthority();
 String file = tempState.getFile();
 String ref = tempState.getRef();
 int hashCode = tempState.getHashCode();


 // Construct authority part
 if (authority == null
 && ((host != null && !host.isEmpty()) || port != -1)) {
 if (host == null)
 host = "";
 authority = (port == -1) ? host : host + ":" + port;

 // Handle hosts with userInfo in them
 int at = host.lastIndexOf('@');
 if (at != -1) {
 userInfo = host.substring(0, at);
 host = host.substring(at+1);
 }
 } else if (authority != null) {
 // Construct user info part
 int ind = authority.indexOf('@');
 if (ind != -1)
 userInfo = authority.substring(0, ind);
 }

 // Construct path and query part
 String path = null;
 String query = null;
 if (file != null) {
 // Fix: only do this if hierarchical?
 int q = file.lastIndexOf('?');
 if (q != -1) {
 query = file.substring(q+1);
 path = file.substring(0, q);
 } else
 path = file;
 }

 // Set the object fields.
 this.protocol = protocol;
 this.host = host;
 this.port = port;
 this.file = file;
 this.authority = authority;
 this.ref = ref;
 this.hashCode = hashCode;
 this.handler = handler;
 this.query = query;
 this.path = path;
 this.userInfo = userInfo;
 replacementURL = this;
 return replacementURL;
 }

 private URL fabricateNewURL()
 throws InvalidObjectException {
 // create URL string from deserialized object
 URL replacementURL = null;
 String urlString = tempState.reconstituteUrlString();

 try {
 replacementURL = new URL(urlString);
 } catch (MalformedURLException mEx) {
 resetState();
 InvalidObjectException invoEx = new InvalidObjectException(
 "Malformed URL: " + urlString);
 invoEx.initCause(mEx);
 throw invoEx;
 }
 replacementURL.setSerializedHashCode(tempState.getHashCode());
 resetState();
 return replacementURL;
 }

 private boolean isBuiltinStreamHandler(String handlerClassName) {
 return (handlerClassName.startsWith(BUILTIN_HANDLERS_PREFIX));
 }

 private void resetState() {
 this.protocol = null;
 this.host = null;
 this.port = -1;
 this.file = null;
 this.authority = null;
 this.ref = null;
 this.hashCode = -1;
 this.handler = null;
 this.query = null;
 this.path = null;
 this.userInfo = null;
 this.tempState = null;
 }

 private void setSerializedHashCode(int hc) {
 this.hashCode = hc;
 }

 static {
 SharedSecrets.setJavaNetURLAccess(
 new JavaNetURLAccess() {
 @Override
 public URLStreamHandler getHandler(URL u) {
 return u.handler;
 }
 }
 );
 }
}

final class UrlDeserializedState {
 private final String protocol;
 private final String host;
 private final int port;
 private final String authority;
 private final String file;
 private final String ref;
 private final int hashCode;

 public UrlDeserializedState(String protocol,
 String host, int port,
 String authority, String file,
 String ref, int hashCode) {
 this.protocol = protocol;
 this.host = host;
 this.port = port;
 this.authority = authority;
 this.file = file;
 this.ref = ref;
 this.hashCode = hashCode;
 }

 String getProtocol() {
 return protocol;
 }

 String getHost() {
 return host;
 }

 String getAuthority () {
 return authority;
 }

 int getPort() {
 return port;
 }

 String getFile () {
 return file;
 }

 String getRef () {
 return ref;
 }

 int getHashCode () {
 return hashCode;
 }

 String reconstituteUrlString() {

 // pre-compute length of StringBuffer
 int len = protocol.length() + 1;
 if (authority != null && !authority.isEmpty())
 len += 2 + authority.length();
 if (file != null) {
 len += file.length();
 }
 if (ref != null)
 len += 1 + ref.length();
 StringBuilder result = new StringBuilder(len);
 result.append(protocol);
 result.append(":");
 if (authority != null && !authority.isEmpty()) {
 result.append("//");
 result.append(authority);
 }
 if (file != null) {
 result.append(file);
 }
 if (ref != null) {
 result.append("#");
 result.append(ref);
 }
 return result.toString();
 }
}