org.apache.tomcat.util.net.URL Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.tomcat.util.net;
import java.io.Serializable;
import java.net.MalformedURLException;
/**
* URL is designed to provide public APIs for parsing
* and synthesizing Uniform Resource Locators as similar as possible to the
* APIs of java.net.URL, but without the ability to open a
* stream or connection. One of the consequences of this is that you can
* construct URLs for protocols for which a URLStreamHandler is not
* available (such as an "https" URL when JSSE is not installed).
*
* WARNING - This class assumes that the string
* representation of a URL conforms to the spec argument
* as described in RFC 2396 "Uniform Resource Identifiers: Generic Syntax":
*
* <scheme>//<authority><path>?<query>#<fragment>
*
*
* FIXME - This class really ought to end up in a Commons
* package someplace.
*
* @author Craig R. McClanahan
* @version $Id: URL.java 939309 2010-04-29 13:54:26Z kkolinko $
*/
public final class URL implements Serializable {
// ----------------------------------------------------------- Constructors
/**
* Create a URL object from the specified String representation.
*
* @param spec String representation of the URL
*
* @exception MalformedURLException if the string representation
* cannot be parsed successfully
*/
public URL(String spec) throws MalformedURLException {
this(null, spec);
}
/**
* Create a URL object by parsing a string representation relative
* to a specified context. Based on logic from JDK 1.3.1's
* java.net.URL.
*
* @param context URL against which the relative representation
* is resolved
* @param spec String representation of the URL (usually relative)
*
* @exception MalformedURLException if the string representation
* cannot be parsed successfully
*/
public URL(URL context, String spec) throws MalformedURLException {
String original = spec;
int i, limit, c;
int start = 0;
String newProtocol = null;
boolean aRef = false;
try {
// Eliminate leading and trailing whitespace
limit = spec.length();
while ((limit > 0) && (spec.charAt(limit - 1) <= ' ')) {
limit--;
}
while ((start < limit) && (spec.charAt(start) <= ' ')) {
start++;
}
// If the string representation starts with "url:", skip it
if (spec.regionMatches(true, start, "url:", 0, 4)) {
start += 4;
}
// Is this a ref relative to the context URL?
if ((start < spec.length()) && (spec.charAt(start) == '#')) {
aRef = true;
}
// Parse out the new protocol
for (i = start; !aRef && (i < limit) ; i++) {
c = spec.charAt(i);
if (c == ':') {
String s = spec.substring(start, i).toLowerCase();
// Assume all protocols are valid
newProtocol = s;
start = i + 1;
break;
} else if( c == '#' ) {
aRef = true;
} else if( !isSchemeChar((char)c) ) {
break;
}
}
// Only use our context if the protocols match
protocol = newProtocol;
if ((context != null) && ((newProtocol == null) ||
newProtocol.equalsIgnoreCase(context.getProtocol()))) {
// 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.getPath() != null) &&
(context.getPath().startsWith("/")))
newProtocol = null;
if (newProtocol == null) {
protocol = context.getProtocol();
authority = context.getAuthority();
userInfo = context.getUserInfo();
host = context.getHost();
port = context.getPort();
file = context.getFile();
int question = file.lastIndexOf("?");
if (question < 0)
path = file;
else
path = file.substring(0, question);
}
}
if (protocol == null)
throw new MalformedURLException("no protocol: " + original);
// Parse out any ref portion of the spec
i = spec.indexOf('#', start);
if (i >= 0) {
ref = spec.substring(i + 1, limit);
limit = i;
}
// Parse the remainder of the spec in a protocol-specific fashion
parse(spec, start, limit);
if (context != null)
normalize();
} catch (MalformedURLException e) {
throw e;
} catch (Exception e) {
throw new MalformedURLException(e.toString());
}
}
/**
* Create a URL object from the specified components. The default port
* number for the specified protocol will be used.
*
* @param protocol Name of the protocol to use
* @param host Name of the host addressed by this protocol
* @param file Filename on the specified host
*
* @exception MalformedURLException is never thrown, but present for
* compatible APIs
*/
public URL(String protocol, String host, String file)
throws MalformedURLException {
this(protocol, host, -1, file);
}
/**
* Create a URL object from the specified components. Specifying a port
* number of -1 indicates that the URL should use the default port for
* that protocol. Based on logic from JDK 1.3.1's
* java.net.URL.
*
* @param protocol Name of the protocol to use
* @param host Name of the host addressed by this protocol
* @param port Port number, or -1 for the default port for this protocol
* @param file Filename on the specified host
*
* @exception MalformedURLException is never thrown, but present for
* compatible APIs
*/
public URL(String protocol, String host, int port, String file)
throws MalformedURLException {
this.protocol = protocol;
this.host = host;
this.port = port;
int hash = file.indexOf('#');
this.file = hash < 0 ? file : file.substring(0, hash);
this.ref = hash < 0 ? null : file.substring(hash + 1);
int question = file.lastIndexOf('?');
if (question >= 0) {
query = file.substring(question + 1);
path = file.substring(0, question);
} else
path = file;
if ((host != null) && (host.length() > 0))
authority = (port == -1) ? host : host + ":" + port;
}
// ----------------------------------------------------- Instance Variables
/**
* The authority part of the URL.
*/
private String authority = null;
/**
* The filename part of the URL.
*/
private String file = null;
/**
* The host name part of the URL.
*/
private String host = null;
/**
* The path part of the URL.
*/
private String path = null;
/**
* The port number part of the URL.
*/
private int port = -1;
/**
* The protocol name part of the URL.
*/
private String protocol = null;
/**
* The query part of the URL.
*/
private String query = null;
/**
* The reference part of the URL.
*/
private String ref = null;
/**
* The user info part of the URL.
*/
private String userInfo = null;
// --------------------------------------------------------- Public Methods
/**
* Compare two URLs for equality. The result is true if and
* only if the argument is not null, and is a URL object
* that represents the same URL as this object. Two
* URLs are equal if they have the same protocol and
* reference the same host, the same port number on the host,
* and the same file and anchor on the host.
*
* @param obj The URL to compare against
*/
@Override
public boolean equals(Object obj) {
if (obj == null)
return (false);
if (!(obj instanceof URL))
return (false);
URL other = (URL) obj;
if (!sameFile(other))
return (false);
return (compare(ref, other.getRef()));
}
/**
* Return the authority part of the URL.
*/
public String getAuthority() {
return (this.authority);
}
/**
* Return the filename part of the URL. NOTE - For
* compatibility with java.net.URL, this value includes
* the query string if there was one. For just the path portion,
* call getPath() instead.
*/
public String getFile() {
if (file == null)
return ("");
return (this.file);
}
/**
* Return the host name part of the URL.
*/
public String getHost() {
return (this.host);
}
/**
* Return the path part of the URL.
*/
public String getPath() {
if (this.path == null)
return ("");
return (this.path);
}
/**
* Return the port number part of the URL.
*/
public int getPort() {
return (this.port);
}
/**
* Return the protocol name part of the URL.
*/
public String getProtocol() {
return (this.protocol);
}
/**
* Return the query part of the URL.
*/
public String getQuery() {
return (this.query);
}
/**
* Return the reference part of the URL.
*/
public String getRef() {
return (this.ref);
}
/**
* Return the user info part of the URL.
*/
public String getUserInfo() {
return (this.userInfo);
}
/**
* Normalize the path (and therefore file)
* portions of this URL.
*
* NOTE - This method is not part of the public API
* of java.net.URL, but is provided as a value added
* service of this implementation.
*
* @exception MalformedURLException if a normalization error occurs,
* such as trying to move about the hierarchical root
*/
public void normalize() throws MalformedURLException {
// Special case for null path
if (path == null) {
if (query != null)
file = "?" + query;
else
file = "";
return;
}
// Create a place for the normalized path
String normalized = path;
if (normalized.equals("/.")) {
path = "/";
if (query != null)
file = path + "?" + query;
else
file = path;
return;
}
// Normalize the slashes and add leading slash if necessary
if (normalized.indexOf('\\') >= 0)
normalized = normalized.replace('\\', '/');
if (!normalized.startsWith("/"))
normalized = "/" + normalized;
// Resolve occurrences of "//" in the normalized path
while (true) {
int index = normalized.indexOf("//");
if (index < 0)
break;
normalized = normalized.substring(0, index) +
normalized.substring(index + 1);
}
// Resolve occurrences of "/./" in the normalized path
while (true) {
int index = normalized.indexOf("/./");
if (index < 0)
break;
normalized = normalized.substring(0, index) +
normalized.substring(index + 2);
}
// Resolve occurrences of "/../" in the normalized path
while (true) {
int index = normalized.indexOf("/../");
if (index < 0)
break;
if (index == 0)
throw new MalformedURLException
("Invalid relative URL reference");
int index2 = normalized.lastIndexOf('/', index - 1);
normalized = normalized.substring(0, index2) +
normalized.substring(index + 3);
}
// Resolve occurrences of "/." at the end of the normalized path
if (normalized.endsWith("/."))
normalized = normalized.substring(0, normalized.length() - 1);
// Resolve occurrences of "/.." at the end of the normalized path
if (normalized.endsWith("/..")) {
int index = normalized.length() - 3;
int index2 = normalized.lastIndexOf('/', index - 1);
if (index2 < 0)
throw new MalformedURLException
("Invalid relative URL reference");
normalized = normalized.substring(0, index2 + 1);
}
// Return the normalized path that we have completed
path = normalized;
if (query != null)
file = path + "?" + query;
else
file = path;
}
/**
* Compare two URLs, excluding the "ref" fields. Returns true
* if this URL and the other argument both refer
* to the same resource. The two URLs might not both contain
* the same anchor.
*/
public boolean sameFile(URL other) {
if (!compare(protocol, other.getProtocol()))
return (false);
if (!compare(host, other.getHost()))
return (false);
if (port != other.getPort())
return (false);
if (!compare(file, other.getFile()))
return (false);
return (true);
}
/**
* Return a string representation of this URL. This follow the rules in
* RFC 2396, Section 5.2, Step 7.
*/
public String toExternalForm() {
StringBuilder sb = new StringBuilder();
if (protocol != null) {
sb.append(protocol);
sb.append(":");
}
if (authority != null) {
sb.append("//");
sb.append(authority);
}
if (path != null)
sb.append(path);
if (query != null) {
sb.append('?');
sb.append(query);
}
if (ref != null) {
sb.append('#');
sb.append(ref);
}
return (sb.toString());
}
/**
* Return a string representation of this object.
*/
@Override
public String toString() {
StringBuilder sb = new StringBuilder("URL[");
sb.append("authority=");
sb.append(authority);
sb.append(", file=");
sb.append(file);
sb.append(", host=");
sb.append(host);
sb.append(", port=");
sb.append(port);
sb.append(", protocol=");
sb.append(protocol);
sb.append(", query=");
sb.append(query);
sb.append(", ref=");
sb.append(ref);
sb.append(", userInfo=");
sb.append(userInfo);
sb.append("]");
return (sb.toString());
// return (toExternalForm());
}
// -------------------------------------------------------- Private Methods
/**
* Compare to String values for equality, taking appropriate care if one
* or both of the values are null.
*
* @param first First string
* @param second Second string
*/
private boolean compare(String first, String second) {
if (first == null) {
if (second == null)
return (true);
else
return (false);
} else {
if (second == null)
return (false);
else
return (first.equals(second));
}
}
/**
* Parse the specified portion of the string representation of a URL,
* assuming that it has a format similar to that for http.
*
*
FIXME - This algorithm can undoubtedly be optimized
* for performance. However, that needs to wait until after sufficient
* unit tests are implemented to guarantee correct behavior with no
* regressions.
*
* @param spec String representation being parsed
* @param start Starting offset, which will be just after the ':' (if
* there is one) that determined the protocol name
* @param limit Ending position, which will be the position of the '#'
* (if there is one) that delimited the anchor
*
* @exception MalformedURLException if a parsing error occurs
*/
private void parse(String spec, int start, int limit)
throws MalformedURLException {
// Trim the query string (if any) off the tail end
int question = spec.lastIndexOf('?', limit - 1);
if ((question >= 0) && (question < limit)) {
query = spec.substring(question + 1, limit);
limit = question;
} else {
query = null;
}
// Parse the authority section
if (spec.indexOf("//", start) == start) {
int pathStart = spec.indexOf("/", start + 2);
if ((pathStart >= 0) && (pathStart < limit)) {
authority = spec.substring(start + 2, pathStart);
start = pathStart;
} else {
authority = spec.substring(start + 2, limit);
start = limit;
}
if (authority.length() > 0) {
int at = authority.indexOf('@');
if( at >= 0 ) {
userInfo = authority.substring(0,at);
}
int ipv6 = authority.indexOf('[',at+1);
int hStart = at+1;
if( ipv6 >= 0 ) {
hStart = ipv6;
ipv6 = authority.indexOf(']', ipv6);
if( ipv6 < 0 ) {
throw new MalformedURLException(
"Closing ']' not found in IPV6 address: " + authority);
} else {
at = ipv6-1;
}
}
int colon = authority.indexOf(':', at+1);
if (colon >= 0) {
try {
port =
Integer.parseInt(authority.substring(colon + 1));
} catch (NumberFormatException e) {
throw new MalformedURLException(e.toString());
}
host = authority.substring(hStart, colon);
} else {
host = authority.substring(hStart);
port = -1;
}
}
}
// Parse the path section
if (spec.indexOf("/", start) == start) { // Absolute path
path = spec.substring(start, limit);
if (query != null)
file = path + "?" + query;
else
file = path;
return;
}
// Resolve relative path against our context's file
if (path == null) {
if (query != null)
file = "?" + query;
else
file = null;
return;
}
if (!path.startsWith("/"))
throw new MalformedURLException
("Base path does not start with '/'");
if (!path.endsWith("/"))
path += "/../";
path += spec.substring(start, limit);
if (query != null)
file = path + "?" + query;
else
file = path;
return;
}
/**
* Determine if the character is allowed in the scheme of a URI.
* See RFC 2396, Section 3.1
*/
public static boolean isSchemeChar(char c) {
return Character.isLetterOrDigit(c) ||
c == '+' || c == '-' || c == '.';
}
}