/*
* @(#)URL.java 1.106 05/03/12
*
* Copyright 1990-2007 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
*
* This program 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.
*
* This program 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 at /legal/license.txt).
*
* 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 Sun Microsystems, Inc., 4150 Network Circle, Santa
* Clara, CA 95054 or visit www.sun.com if you need additional
* information or have any questions.
*
*/
package com.sun.perseus.platform;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Hashtable;
/**
* Class <code>URL</code> 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:
* <blockquote>
* <a href="http://archive.ncsa.uiuc.edu/SDG/Software/Mosaic/Demo/url-primer.html">
* <i>http://archive.ncsa.uiuc.edu/SDG/Software/Mosaic/Demo/url-primer.html</i></a>
* </blockquote>
* <p>
* In general, a URL can be broken into several parts. The previous
* example of a URL indicates that the protocol to use is
* <code>http</code> (HyperText Transfer Protocol) and that the
* information resides on a host machine named
* <code>www.ncsa.uiuc.edu</code>. The information on that host
* machine is named <code>/SDG/Software/Mosaic/Demo/url-primer.html</code>. 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</code> is <code>80</code>. An alternative port could be
* specified as:
* <blockquote><pre>
* http://archive.ncsa.uiuc.edu:80/SDG/Software/Mosaic/Demo/url-primer.html
* </pre></blockquote>
* <p>
* The syntax of <code>URL</code> is defined by <a
* href="http://www.ietf.org/rfc/rfc2396.txt""><i>RFC 2396: Uniform
* Resource Identifiers (URI): Generic Syntax</i></a>, amended by <a
* href="http://www.ietf.org/rfc/rfc2732.txt"><i>RFC 2732: Format for
* Literal IPv6 Addresses in URLs</i></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://java.sun.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</code> 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://java.sun.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://java.sun.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.
*
*/
public final class PURL {
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</code> is
* defined as <code>path[?query]</code>
* @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 Object hostAddress;
/* Our hash code.
* @serial
*/
private int hashCode = -1;
/**
* Creates a <code>URL</code> object from the <code>String</code>
* representation.
* <p>
* This constructor is equivalent to a call to the two-argument
* constructor with a <code>null</code> first argument.
*
* @param spec the <code>String</code> to parse as a URL.
* @exception Error If the string specifies an
* unknown protocol.
* @see java.net.URL#URL(java.net.URL, java.lang.String)
*/
public PURL(String spec) throws Error {
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 "Uniform Resource Identifiers : Generic * Syntax" :
* <blockquote><pre>
* <scheme>://<authority><path>?<query>#<fragment>
* </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
* "/" 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 occurences of ".." and ".".
* <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</code> to parse as a URL.
* @exception Error if no protocol is specified, or an
* unknown protocol is found.
* @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 PURL(PURL context, String spec) throws Error {
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</code> to parse as a URL.
* @param handler the stream handler for the URL.
* @exception Error if no protocol is specified, or an
* unknown protocol is found.
* @exception SecurityException
* if a security manager exists and its
* <code>checkPermission</code> 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 PURL(PURL context, String spec, Object handler)
throws Error
{
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 = spec.substring(start, i).toLowerCase();
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))) {
// 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 Error("no protocol: "+original);
}
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;
}
}
PURLStreamHandler.parseURL(this, spec, start, limit);
} catch(Error e) {
throw e;
} catch(Exception e) {
throw new Error(e.getMessage());
}
}
/*
* 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.isLowerCase(c) ||
Character.isUpperCase(c)))
return false;
for (int i = 1; i < len; i++) {
c = protocol.charAt(i);
if (!(Character.isLowerCase(c) ||
Character.isUpperCase(c) ||
Character.isDigit(c))
&& c != '.' && c != '+' &&
c != '-') {
return false;
}
}
return true;
}
/**
* 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
*/
protected 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
*/
protected 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</code>.
*
* @return the query part of this <code>URL</code>,
* 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</code>.
*
* @return the path part of this <code>URL</code>, 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</code>.
*
* @return the userInfo part of this <code>URL</code>, or
* <CODE>null</CODE> if one does not exist
*/
public String getUserInfo() {
return userInfo;
}
/**
* Gets the authority part of this <code>URL</code>.
*
* @return the authority part of this <code>URL</code>
* @since 1.3
*/
public String getAuthority() {
return authority;
}
/**
* Gets the port number of this <code>URL</code>.
*
* @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</code>. 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
*/
public int getDefaultPort() {
return -1;
//return handler.getDefaultPort();
}
/**
* Gets the protocol name of this <code>URL</code>.
*
* @return the protocol of this <code>URL</code>.
*/
public String getProtocol() {
return protocol;
}
/**
* Gets the host name of this <code>URL</code>, 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 (<tt>'['</tt> and <tt>']'</tt>).
*
* @return the host name of this <code>URL</code>.
*/
public String getHost() {
return host;
}
/**
* Gets the file name of this <code>URL</code>.
* 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</code>,
* 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</code>.
*
* @return the anchor (also known as the "reference") of this
* <code>URL</code>, or <CODE>null</CODE> if one does not exist
*/
public String getRef() {
return ref;
}
/**
* Constructs a string representation of this <code>URL</code>. The
* string is created by calling the <code>toExternalForm</code>
* 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</code>. The
* string is created by calling the <code>toExternalForm</code>
* 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 PURLStreamHandler.toExternalForm(this);
}
}
class Parts {
String path, query, ref;
Parts(String file) {
int ind = file.indexOf('#');
ref = ind < 0 ? null: file.substring(ind + 1);
file = ind < 0 ? file: file.substring(0, ind);
int q = file.lastIndexOf('?');
if (q != -1) {
query = file.substring(q+1);
path = file.substring(0, q);
} else {
path = file;
}
}
String getPath() {
return path;
}
String getQuery() {
return query;
}
String getRef() {
return ref;
}
}
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