/**
* URL utilities class that makes it easy to create new URLs based off of old URLs without having to
* assemble or parse them yourself.
*
* @version $Revision: 1.1 $
* @author Daniel Gredler
* @author Martin Tamme
* @author Sudhan Moghe
* @author Marc Guillemot
* @author Ahmed Ashour
* @author Ronald Brill
*/
public final class UrlUtils {
private static final BitSet PATH_ALLOWED_CHARS = new BitSet(256);
private static final BitSet QUERY_ALLOWED_CHARS = new BitSet(256);
private static final BitSet ANCHOR_ALLOWED_CHARS = new BitSet(256);
private static final URLCreator URL_CREATOR = URLCreator.getCreator();
/** URI allowed char initialization; based on HttpClient 3.1's URI bit sets. */
static {
final BitSet reserved = new BitSet(256);
reserved.set(';');
reserved.set('/');
reserved.set('?');
reserved.set(':');
reserved.set('@');
reserved.set('&');
reserved.set('=');
reserved.set('+');
reserved.set('$');
reserved.set(',');
final BitSet mark = new BitSet(256);
mark.set('-');
mark.set('_');
mark.set('.');
mark.set('!');
mark.set('~');
mark.set('*');
mark.set('\'');
mark.set('(');
mark.set(')');
final BitSet alpha = new BitSet(256);
for (int i = 'a'; i <= 'z'; i++) {
alpha.set(i);
}
for (int i = 'A'; i <= 'Z'; i++) {
alpha.set(i);
}
final BitSet digit = new BitSet(256);
for (int i = '0'; i <= '9'; i++) {
digit.set(i);
}
final BitSet alphanumeric = new BitSet(256);
alphanumeric.or(alpha);
alphanumeric.or(digit);
final BitSet unreserved = new BitSet(256);
unreserved.or(alphanumeric);
unreserved.or(mark);
final BitSet hex = new BitSet(256);
hex.or(digit);
for (int i = 'a'; i <= 'f'; i++) {
hex.set(i);
}
for (int i = 'A'; i <= 'F'; i++) {
hex.set(i);
}
final BitSet escaped = new BitSet(256);
escaped.set('%');
escaped.or(hex);
final BitSet uric = new BitSet(256);
uric.or(reserved);
uric.or(unreserved);
uric.or(escaped);
final BitSet pchar = new BitSet(256);
pchar.or(unreserved);
pchar.or(escaped);
pchar.set(':');
pchar.set('@');
pchar.set('&');
pchar.set('=');
pchar.set('+');
pchar.set('$');
pchar.set(',');
final BitSet param = pchar;
final BitSet segment = new BitSet(256);
segment.or(pchar);
segment.set(';');
segment.or(param);
final BitSet pathSegments = new BitSet(256);
pathSegments.set('/');
pathSegments.or(segment);
final BitSet absPath = new BitSet(256);
absPath.set('/');
absPath.or(pathSegments);
final BitSet allowedAbsPath = new BitSet(256);
allowedAbsPath.or(absPath);
final BitSet allowedFragment = new BitSet(256);
allowedFragment.or(uric);
// allowedFragment.clear('%');
final BitSet allowedQuery = new BitSet(256);
allowedQuery.or(uric);
PATH_ALLOWED_CHARS.or(allowedAbsPath);
QUERY_ALLOWED_CHARS.or(allowedQuery);
ANCHOR_ALLOWED_CHARS.or(allowedFragment);
}
/** Disallow instantiation of this class. */
private UrlUtils() {
// Empty.
}
/**
* Constructs a URL instance based on the specified URL string, taking into account the fact that
* the specified URL string may represent an <tt>"about:..."</tt> URL, a <tt>"javascript:..."</tt>
* URL, or a <tt>data:...</tt> URL.
*
* <p>The caller should be sure that URL strings passed to this method will parse correctly as
* URLs, as this method never expects to have to handle {@link MalformedURLException}s.
*
* @param url the URL string to convert into a URL instance
* @return the constructed URL instance
*/
public static URL toUrlSafe(final String url) {
try {
return toUrlUnsafe(url);
} catch (final MalformedURLException e) {
// Should never happen.
throw new RuntimeException(e);
}
}
/**
* Constructs a URL instance based on the specified URL string, taking into account the fact that
* the specified URL string may represent an <tt>"about:..."</tt> URL, a <tt>"javascript:..."</tt>
* URL, or a <tt>data:...</tt> URL.
*
* <p>Unlike {@link #toUrlSafe(String)}, the caller need not be sure that URL strings passed to
* this method will parse correctly as URLs.
*
* @param url the URL string to convert into a URL instance
* @return the constructed URL instance
* @throws MalformedURLException if the URL string cannot be converted to a URL instance
*/
public static URL toUrlUnsafe(final String url) throws MalformedURLException {
WebAssert.notNull("url", url);
return URL_CREATOR.toUrlUnsafeClassic(url);
}
/**
* Encodes illegal characters in the specified URL's path, query string and anchor according to
* the URL encoding rules observed in real browsers.
*
* <p>For example, this method changes <tt>"http://first/?a=b c"</tt> to
* <tt>"http://first/?a=b%20c"</tt>.
*
* @param url the URL to encode
* @param minimalQueryEncoding whether or not to perform minimal query encoding, like IE does
* @return the encoded URL
* @deprecated as of 2.12, please use {@link #encodeUrl(URL, boolean, String)} instead
*/
@Deprecated
public static URL encodeUrl(final URL url, final boolean minimalQueryEncoding) {
return encodeUrl(url, minimalQueryEncoding, TextUtil.DEFAULT_CHARSET);
}
/**
* Encodes illegal characters in the specified URL's path, query string and anchor according to
* the URL encoding rules observed in real browsers.
*
* <p>For example, this method changes <tt>"http://first/?a=b c"</tt> to
* <tt>"http://first/?a=b%20c"</tt>.
*
* @param url the URL to encode
* @param minimalQueryEncoding whether or not to perform minimal query encoding, like IE does
* @param charset the charset
* @return the encoded URL
*/
public static URL encodeUrl(
final URL url, final boolean minimalQueryEncoding, final String charset) {
final String p = url.getProtocol();
if ("javascript".equalsIgnoreCase(p)
|| "about".equalsIgnoreCase(p)
|| "data".equalsIgnoreCase(p)) {
// Special exception.
return url;
}
try {
String path = url.getPath();
if (path != null) {
path = encode(path, PATH_ALLOWED_CHARS, "UTF-8");
}
String query = url.getQuery();
if (query != null) {
if (minimalQueryEncoding) {
query = org.apache.commons.lang3.StringUtils.replace(query, " ", "%20");
} else {
query = encode(query, QUERY_ALLOWED_CHARS, charset);
}
}
String anchor = url.getRef();
if (anchor != null) {
anchor = encode(anchor, ANCHOR_ALLOWED_CHARS, "UTF-8");
}
return createNewUrl(url.getProtocol(), url.getHost(), url.getPort(), path, anchor, query);
} catch (final MalformedURLException e) {
// Impossible... I think.
throw new RuntimeException(e);
}
}
/**
* Encodes and escapes the specified URI anchor string.
*
* @param anchor the anchor string to encode and escape
* @return the encoded and escaped anchor string
*/
public static String encodeAnchor(String anchor) {
if (anchor != null) {
anchor = encode(anchor, ANCHOR_ALLOWED_CHARS, "UTF-8");
}
return anchor;
}
/**
* Unescapes and decodes the specified string.
*
* @param escaped the string to be unescaped and decoded
* @return the unescaped and decoded string
*/
public static String decode(final String escaped) {
try {
final byte[] bytes = escaped.getBytes("US-ASCII");
final byte[] bytes2 = URLCodec.decodeUrl(bytes);
return new String(bytes2, "UTF-8");
} catch (final UnsupportedEncodingException e) {
// Should never happen.
throw new RuntimeException(e);
} catch (final DecoderException e) {
// Should never happen.
throw new RuntimeException(e);
}
}
/**
* Escapes and encodes the specified string. Based on HttpClient 3.1's <tt>URIUtil.encode()</tt>
* method.
*
* @param unescaped the string to encode
* @param allowed allowed characters that shouldn't be escaped
* @param charset the charset to use
* @return the escaped string
*/
private static String encode(final String unescaped, final BitSet allowed, final String charset) {
try {
final byte[] bytes = unescaped.getBytes(charset);
final byte[] bytes2 = URLCodec.encodeUrl(allowed, bytes);
return new String(bytes2, "US-ASCII");
} catch (final UnsupportedEncodingException e) {
// Should never happen.
throw new RuntimeException(e);
}
}
/**
* Creates and returns a new URL identical to the specified URL, except using the specified
* protocol.
*
* @param u the URL on which to base the returned URL
* @param newProtocol the new protocol to use in the returned URL
* @return a new URL identical to the specified URL, except using the specified protocol
* @throws MalformedURLException if there is a problem creating the new URL
*/
public static URL getUrlWithNewProtocol(final URL u, final String newProtocol)
throws MalformedURLException {
return createNewUrl(newProtocol, u.getAuthority(), u.getPath(), u.getRef(), u.getQuery());
}
/**
* Creates and returns a new URL identical to the specified URL, except using the specified host.
*
* @param u the URL on which to base the returned URL
* @param newHost the new host to use in the returned URL
* @return a new URL identical to the specified URL, except using the specified host
* @throws MalformedURLException if there is a problem creating the new URL
*/
public static URL getUrlWithNewHost(final URL u, final String newHost)
throws MalformedURLException {
return createNewUrl(
u.getProtocol(), newHost, u.getPort(), u.getPath(), u.getRef(), u.getQuery());
}
/**
* Creates and returns a new URL identical to the specified URL, except using the specified host.
*
* @param u the URL on which to base the returned URL
* @param newHost the new host to use in the returned URL
* @param newPort the new port to use in the returned URL
* @return a new URL identical to the specified URL, except using the specified host
* @throws MalformedURLException if there is a problem creating the new URL
*/
public static URL getUrlWithNewHostAndPort(final URL u, final String newHost, final int newPort)
throws MalformedURLException {
return createNewUrl(u.getProtocol(), newHost, newPort, u.getPath(), u.getRef(), u.getQuery());
}
/**
* Creates and returns a new URL identical to the specified URL, except using the specified port.
*
* @param u the URL on which to base the returned URL
* @param newPort the new port to use in the returned URL
* @return a new URL identical to the specified URL, except using the specified port
* @throws MalformedURLException if there is a problem creating the new URL
*/
public static URL getUrlWithNewPort(final URL u, final int newPort) throws MalformedURLException {
return createNewUrl(
u.getProtocol(), u.getHost(), newPort, u.getPath(), u.getRef(), u.getQuery());
}
/**
* Creates and returns a new URL identical to the specified URL, except using the specified path.
*
* @param u the URL on which to base the returned URL
* @param newPath the new path to use in the returned URL
* @return a new URL identical to the specified URL, except using the specified path
* @throws MalformedURLException if there is a problem creating the new URL
*/
public static URL getUrlWithNewPath(final URL u, final String newPath)
throws MalformedURLException {
return createNewUrl(u.getProtocol(), u.getAuthority(), newPath, u.getRef(), u.getQuery());
}
/**
* Creates and returns a new URL identical to the specified URL, except using the specified
* reference.
*
* @param u the URL on which to base the returned URL
* @param newRef the new reference to use in the returned URL
* @return a new URL identical to the specified URL, except using the specified reference
* @throws MalformedURLException if there is a problem creating the new URL
*/
public static URL getUrlWithNewRef(final URL u, final String newRef)
throws MalformedURLException {
return createNewUrl(u.getProtocol(), u.getAuthority(), u.getPath(), newRef, u.getQuery());
}
/**
* Creates and returns a new URL identical to the specified URL, except using the specified query
* string.
*
* @param u the URL on which to base the returned URL
* @param newQuery the new query string to use in the returned URL
* @return a new URL identical to the specified URL, except using the specified query string
* @throws MalformedURLException if there is a problem creating the new URL
*/
public static URL getUrlWithNewQuery(final URL u, final String newQuery)
throws MalformedURLException {
return createNewUrl(u.getProtocol(), u.getAuthority(), u.getPath(), u.getRef(), newQuery);
}
/**
* Creates a new URL based on the specified fragments.
*
* @param protocol the protocol to use (may not be <tt>null</tt>)
* @param host the host to use (may not be <tt>null</tt>)
* @param port the port to use (may be <tt>-1</tt> if no port is specified)
* @param path the path to use (may be <tt>null</tt> and may omit the initial <tt>'/'</tt>)
* @param ref the reference to use (may be <tt>null</tt> and must not include the <tt>'#'</tt>)
* @param query the query to use (may be <tt>null</tt> and must not include the <tt>'?'</tt>)
* @return a new URL based on the specified fragments
* @throws MalformedURLException if there is a problem creating the new URL
*/
private static URL createNewUrl(
final String protocol,
final String host,
final int port,
final String path,
final String ref,
final String query)
throws MalformedURLException {
final StringBuilder s = new StringBuilder();
s.append(protocol);
s.append("://");
s.append(host);
if (port != -1) {
s.append(":").append(port);
}
if (path != null && path.length() > 0) {
if (!('/' == path.charAt(0))) {
s.append("/");
}
s.append(path);
}
if (query != null) {
s.append("?").append(query);
}
if (ref != null) {
if (!((ref.length() > 0) && ('#' == ref.charAt(0)))) {
s.append("#");
}
s.append(ref);
}
final URL url = new URL(s.toString());
return url;
}
/**
* Creates a new URL based on the specified fragments.
*
* @param protocol the protocol to use (may not be <tt>null</tt>)
* @param authority the authority to use (may not be <tt>null</tt>)
* @param path the path to use (may be <tt>null</tt> and may omit the initial <tt>'/'</tt>)
* @param ref the reference to use (may be <tt>null</tt> and must not include the <tt>'#'</tt>)
* @param query the query to use (may be <tt>null</tt> and must not include the <tt>'?'</tt>)
* @return a new URL based on the specified fragments
* @throws MalformedURLException if there is a problem creating the new URL
*/
private static URL createNewUrl(
final String protocol,
final String authority,
final String path,
final String ref,
final String query)
throws MalformedURLException {
// pre-compute length of StringBuffer
int len = protocol.length() + 1;
if (authority != null && authority.length() > 0) {
len += 2 + authority.length();
}
if (path != null) {
len += path.length();
}
if (query != null) {
len += 1 + query.length();
}
if (ref != null) {
len += 1 + ref.length();
}
final StringBuffer s = new StringBuffer(len);
s.append(protocol);
s.append(":");
if (authority != null && authority.length() > 0) {
s.append("//");
s.append(authority);
}
if (path != null) {
s.append(path);
}
if (query != null) {
s.append('?');
s.append(query);
}
if (ref != null) {
if (!((ref.length() > 0) && ('#' == ref.charAt(0)))) {
s.append("#");
}
s.append(ref);
}
final URL url = new URL(s.toString());
return url;
}
/**
* Resolves a given relative URL against a base URL. See <a
* href="http://www.faqs.org/rfcs/rfc1808.html">RFC1808</a> Section 4 for more details.
*
* @param baseUrl The base URL in which to resolve the specification.
* @param relativeUrl The relative URL to resolve against the base URL.
* @return the resolved specification.
*/
public static String resolveUrl(final String baseUrl, final String relativeUrl) {
if (baseUrl == null) {
throw new IllegalArgumentException("Base URL must not be null");
}
if (relativeUrl == null) {
throw new IllegalArgumentException("Relative URL must not be null");
}
final Url url = resolveUrl(parseUrl(baseUrl.trim()), relativeUrl.trim());
return url.toString();
}
/**
* Resolves a given relative URL against a base URL. See <a
* href="http://www.faqs.org/rfcs/rfc1808.html">RFC1808</a> Section 4 for more details.
*
* @param baseUrl The base URL in which to resolve the specification.
* @param relativeUrl The relative URL to resolve against the base URL.
* @return the resolved specification.
*/
public static String resolveUrl(final URL baseUrl, final String relativeUrl) {
if (baseUrl == null) {
throw new IllegalArgumentException("Base URL must not be null");
}
return resolveUrl(baseUrl.toExternalForm(), relativeUrl);
}
/**
* Parses a given specification using the algorithm depicted in <a
* href="http://www.faqs.org/rfcs/rfc1808.html">RFC1808</a>:
*
* <p>Section 2.4: Parsing a URL
*
* <p>An accepted method for parsing URLs is useful to clarify the generic-RL syntax of Section
* 2.2 and to describe the algorithm for resolving relative URLs presented in Section 4. This
* section describes the parsing rules for breaking down a URL (relative or absolute) into the
* component parts described in Section 2.1. The rules assume that the URL has already been
* separated from any surrounding text and copied to a "parse string". The rules are listed in the
* order in which they would be applied by the parser.
*
* @param spec The specification to parse.
* @return the parsed specification.
*/
private static Url parseUrl(final String spec) {
final Url url = new Url();
int startIndex = 0;
int endIndex = spec.length();
// Section 2.4.1: Parsing the Fragment Identifier
//
// If the parse string contains a crosshatch "#" character, then the
// substring after the first (left-most) crosshatch "#" and up to the
// end of the parse string is the <fragment> identifier. If the
// crosshatch is the last character, or no crosshatch is present, then
// the fragment identifier is empty. The matched substring, including
// the crosshatch character, is removed from the parse string before
// continuing.
//
// Note that the fragment identifier is not considered part of the URL.
// However, since it is often attached to the URL, parsers must be able
// to recognize and set aside fragment identifiers as part of the
// process.
final int crosshatchIndex = StringUtils.indexOf(spec, '#', startIndex, endIndex);
if (crosshatchIndex >= 0) {
url.fragment_ = spec.substring(crosshatchIndex + 1, endIndex);
endIndex = crosshatchIndex;
}
// Section 2.4.2: Parsing the Scheme
//
// If the parse string contains a colon ":" after the first character
// and before any characters not allowed as part of a scheme name (i.e.,
// any not an alphanumeric, plus "+", period ".", or hyphen "-"), the
// <scheme> of the URL is the substring of characters up to but not
// including the first colon. These characters and the colon are then
// removed from the parse string before continuing.
final int colonIndex = StringUtils.indexOf(spec, ':', startIndex, endIndex);
if (colonIndex > 0) {
final String scheme = spec.substring(startIndex, colonIndex);
if (isValidScheme(scheme)) {
url.scheme_ = scheme;
startIndex = colonIndex + 1;
}
}
// Section 2.4.3: Parsing the Network Location/Login
//
// If the parse string begins with a double-slash "//", then the
// substring of characters after the double-slash and up to, but not
// including, the next slash "/" character is the network location/login
// (<net_loc>) of the URL. If no trailing slash "/" is present, the
// entire remaining parse string is assigned to <net_loc>. The double-
// slash and <net_loc> are removed from the parse string before
// continuing.
//
// Note: We also accept a question mark "?" or a semicolon ";" character as
// delimiters for the network location/login (<net_loc>) of the URL.
final int locationStartIndex;
int locationEndIndex;
if (spec.startsWith("//", startIndex)) {
locationStartIndex = startIndex + 2;
locationEndIndex = StringUtils.indexOf(spec, '/', locationStartIndex, endIndex);
if (locationEndIndex >= 0) {
startIndex = locationEndIndex;
}
} else {
locationStartIndex = -1;
locationEndIndex = -1;
}
// Section 2.4.4: Parsing the Query Information
//
// If the parse string contains a question mark "?" character, then the
// substring after the first (left-most) question mark "?" and up to the
// end of the parse string is the <query> information. If the question
// mark is the last character, or no question mark is present, then the
// query information is empty. The matched substring, including the
// question mark character, is removed from the parse string before
// continuing.
final int questionMarkIndex = StringUtils.indexOf(spec, '?', startIndex, endIndex);
if (questionMarkIndex >= 0) {
if ((locationStartIndex >= 0) && (locationEndIndex < 0)) {
// The substring of characters after the double-slash and up to, but not
// including, the question mark "?" character is the network location/login
// (<net_loc>) of the URL.
locationEndIndex = questionMarkIndex;
startIndex = questionMarkIndex;
}
url.query_ = spec.substring(questionMarkIndex + 1, endIndex);
endIndex = questionMarkIndex;
}
// Section 2.4.5: Parsing the Parameters
//
// If the parse string contains a semicolon ";" character, then the
// substring after the first (left-most) semicolon ";" and up to the end
// of the parse string is the parameters (<params>). If the semicolon
// is the last character, or no semicolon is present, then <params> is
// empty. The matched substring, including the semicolon character, is
// removed from the parse string before continuing.
final int semicolonIndex = StringUtils.indexOf(spec, ';', startIndex, endIndex);
if (semicolonIndex >= 0) {
if ((locationStartIndex >= 0) && (locationEndIndex < 0)) {
// The substring of characters after the double-slash and up to, but not
// including, the semicolon ";" character is the network location/login
// (<net_loc>) of the URL.
locationEndIndex = semicolonIndex;
startIndex = semicolonIndex;
}
url.parameters_ = spec.substring(semicolonIndex + 1, endIndex);
endIndex = semicolonIndex;
}
// Section 2.4.6: Parsing the Path
//
// After the above steps, all that is left of the parse string is the
// URL <path> and the slash "/" that may precede it. Even though the
// initial slash is not part of the URL path, the parser must remember
// whether or not it was present so that later processes can
// differentiate between relative and absolute paths. Often this is
// done by simply storing the preceding slash along with the path.
if ((locationStartIndex >= 0) && (locationEndIndex < 0)) {
// The entire remaining parse string is assigned to the network
// location/login (<net_loc>) of the URL.
locationEndIndex = endIndex;
} else if (startIndex < endIndex) {
url.path_ = spec.substring(startIndex, endIndex);
}
// Set the network location/login (<net_loc>) of the URL.
if ((locationStartIndex >= 0) && (locationEndIndex >= 0)) {
url.location_ = spec.substring(locationStartIndex, locationEndIndex);
}
return url;
}
/*
* Returns true if specified string is a valid scheme name.
*/
private static boolean isValidScheme(final String scheme) {
final int length = scheme.length();
if (length < 1) {
return false;
}
char c = scheme.charAt(0);
if (!Character.isLetter(c)) {
return false;
}
for (int i = 1; i < length; i++) {
c = scheme.charAt(i);
if (!Character.isLetterOrDigit(c) && c != '.' && c != '+' && c != '-') {
return false;
}
}
return true;
}
/**
* Resolves a given relative URL against a base URL using the algorithm depicted in <a
* href="http://www.faqs.org/rfcs/rfc1808.html">RFC1808</a>:
*
* <p>Section 4: Resolving Relative URLs
*
* <p>This section describes an example algorithm for resolving URLs within a context in which the
* URLs may be relative, such that the result is always a URL in absolute form. Although this
* algorithm cannot guarantee that the resulting URL will equal that intended by the original
* author, it does guarantee that any valid URL (relative or absolute) can be consistently
* transformed to an absolute form given a valid base URL.
*
* @param baseUrl The base URL in which to resolve the specification.
* @param relativeUrl The relative URL to resolve against the base URL.
* @return the resolved specification.
*/
private static Url resolveUrl(final Url baseUrl, final String relativeUrl) {
final Url url = parseUrl(relativeUrl);
// Step 1: The base URL is established according to the rules of
// Section 3. If the base URL is the empty string (unknown),
// the embedded URL is interpreted as an absolute URL and
// we are done.
if (baseUrl == null) {
return url;
}
// Step 2: Both the base and embedded URLs are parsed into their
// component parts as described in Section 2.4.
// a) If the embedded URL is entirely empty, it inherits the
// entire base URL (i.e., is set equal to the base URL)
// and we are done.
if (relativeUrl.isEmpty()) {
return new Url(baseUrl);
}
// b) If the embedded URL starts with a scheme name, it is
// interpreted as an absolute URL and we are done.
if (url.scheme_ != null) {
return url;
}
// c) Otherwise, the embedded URL inherits the scheme of
// the base URL.
url.scheme_ = baseUrl.scheme_;
// Step 3: If the embedded URL's <net_loc> is non-empty, we skip to
// Step 7. Otherwise, the embedded URL inherits the <net_loc>
// (if any) of the base URL.
if (url.location_ != null) {
return url;
}
url.location_ = baseUrl.location_;
// Step 4: If the embedded URL path is preceded by a slash "/", the
// path is not relative and we skip to Step 7.
if ((url.path_ != null) && ((url.path_.length() > 0) && ('/' == url.path_.charAt(0)))) {
url.path_ = removeLeadingSlashPoints(url.path_);
return url;
}
// Step 5: If the embedded URL path is empty (and not preceded by a
// slash), then the embedded URL inherits the base URL path,
// and
if (url.path_ == null) {
url.path_ = baseUrl.path_;
// a) if the embedded URL's <params> is non-empty, we skip to
// step 7; otherwise, it inherits the <params> of the base
// URL (if any) and
if (url.parameters_ != null) {
return url;
}
url.parameters_ = baseUrl.parameters_;
// b) if the embedded URL's <query> is non-empty, we skip to
// step 7; otherwise, it inherits the <query> of the base
// URL (if any) and we skip to step 7.
if (url.query_ != null) {
return url;
}
url.query_ = baseUrl.query_;
return url;
}
// Step 6: The last segment of the base URL's path (anything
// following the rightmost slash "/", or the entire path if no
// slash is present) is removed and the embedded URL's path is
// appended in its place. The following operations are
// then applied, in order, to the new path:
final String basePath = baseUrl.path_;
String path = "";
if (basePath != null) {
final int lastSlashIndex = basePath.lastIndexOf('/');
if (lastSlashIndex >= 0) {
path = basePath.substring(0, lastSlashIndex + 1);
}
} else {
path = "/";
}
path = path.concat(url.path_);
// a) All occurrences of "./", where "." is a complete path
// segment, are removed.
int pathSegmentIndex;
while ((pathSegmentIndex = path.indexOf("/./")) >= 0) {
path = path.substring(0, pathSegmentIndex + 1).concat(path.substring(pathSegmentIndex + 3));
}
// b) If the path ends with "." as a complete path segment,
// that "." is removed.
if (path.endsWith("/.")) {
path = path.substring(0, path.length() - 1);
}
// c) All occurrences of "<segment>/../", where <segment> is a
// complete path segment not equal to "..", are removed.
// Removal of these path segments is performed iteratively,
// removing the leftmost matching pattern on each iteration,
// until no matching pattern remains.
while ((pathSegmentIndex = path.indexOf("/../")) > 0) {
final String pathSegment = path.substring(0, pathSegmentIndex);
final int slashIndex = pathSegment.lastIndexOf('/');
if (slashIndex >= 0) {
if (!"..".equals(pathSegment.substring(slashIndex))) {
path = path.substring(0, slashIndex + 1).concat(path.substring(pathSegmentIndex + 4));
}
} else {
path = path.substring(pathSegmentIndex + 4);
}
}
// d) If the path ends with "<segment>/..", where <segment> is a
// complete path segment not equal to "..", that
// "<segment>/.." is removed.
if (path.endsWith("/..")) {
final String pathSegment = path.substring(0, path.length() - 3);
final int slashIndex = pathSegment.lastIndexOf('/');
if (slashIndex >= 0) {
path = path.substring(0, slashIndex + 1);
}
}
path = removeLeadingSlashPoints(path);
url.path_ = path;
// Step 7: The resulting URL components, including any inherited from
// the base URL, are recombined to give the absolute form of
// the embedded URL.
return url;
}
/** "/.." at the beginning should be removed as browsers do (not in RFC) */
private static String removeLeadingSlashPoints(String path) {
while (path.startsWith("/..")) {
path = path.substring(3);
}
return path;
}
/**
* Class <tt>Url</tt> represents a Uniform Resource Locator.
*
* @author Martin Tamme
*/
private static class Url {
private String scheme_;
private String location_;
private String path_;
private String parameters_;
private String query_;
private String fragment_;
/** Creates a <tt>Url</tt> object. */
public Url() {}
/**
* Creates a <tt>Url</tt> object from the specified <tt>Url</tt> object.
*
* @param url a <tt>Url</tt> object.
*/
public Url(final Url url) {
scheme_ = url.scheme_;
location_ = url.location_;
path_ = url.path_;
parameters_ = url.parameters_;
query_ = url.query_;
fragment_ = url.fragment_;
}
/**
* Returns a string representation of the <tt>Url</tt> object.
*
* @return a string representation of the <tt>Url</tt> object.
*/
@Override
public String toString() {
final StringBuilder sb = new StringBuilder();
if (scheme_ != null) {
sb.append(scheme_);
sb.append(':');
}
if (location_ != null) {
sb.append("//");
sb.append(location_);
}
if (path_ != null) {
sb.append(path_);
}
if (parameters_ != null) {
sb.append(';');
sb.append(parameters_);
}
if (query_ != null) {
sb.append('?');
sb.append(query_);
}
if (fragment_ != null) {
sb.append('#');
sb.append(fragment_);
}
return sb.toString();
}
}
}
/**
* Constructs a URL instance based on the specified URL string, taking into account the fact that
* the specified URL string may represent an <tt>"about:..."</tt> URL, a <tt>"javascript:..."</tt>
* URL, or a <tt>data:...</tt> URL.
*
* <p>Unlike {@link #toUrlSafe(String)}, the caller need not be sure that URL strings passed to
* this method will parse correctly as URLs.
*
* @param url the URL string to convert into a URL instance
* @return the constructed URL instance
* @throws MalformedURLException if the URL string cannot be converted to a URL instance
*/
public static URL toUrlUnsafe(final String url) throws MalformedURLException {
WebAssert.notNull("url", url);
return URL_CREATOR.toUrlUnsafeClassic(url);
}
