/**
* Sets the properties of this URL using the provided arguments. Only a {@code URLStreamHandler}
* can use this method to set fields of the existing URL instance. A URL is generally constant.
*
* @param protocol the protocol to be set.
* @param host the host name to be set.
* @param port the port number to be set.
* @param authority the authority to be set.
* @param userInfo the user-info to be set.
* @param path the path to be set.
* @param query the query to be set.
* @param ref the reference to be set.
*/
protected void set(
String protocol,
String host,
int port,
String authority,
String userInfo,
String path,
String query,
String ref) {
String filePart = path;
if (query != null && !query.isEmpty()) {
if (filePart != null) {
filePart = filePart + "?" + query;
} else {
filePart = "?" + query;
}
}
set(protocol, host, port, filePart, ref);
this.authority = authority;
this.userInfo = userInfo;
this.path = path;
this.query = query;
}
/**
* Creates a new URL to the specified resource {@code spec}. This URL is relative to the given
* {@code context}. The {@code handler} will be used to parse the URL string representation. If
* this argument is {@code null} the default {@code URLStreamHandler} will be used. If the
* protocol of the parsed URL does not match with the protocol of the context URL, then the newly
* created URL is absolute and bases only on the given URL represented by {@code spec}. Otherwise
* the protocol is defined by the context URL.
*
* @param context the URL which is used as the context.
* @param spec the URL string representation which has to be parsed.
* @param handler the specific stream handler to be used by this URL.
* @throws IOException if the given string {@code spec} could not be parsed as a URL or an invalid
* protocol has been found.
*/
public URL(URL context, String spec) throws MalformedURLException {
if (spec == null) {
throw new MalformedURLException();
}
spec = spec.trim();
this.spec = spec;
// The spec includes a protocol if it includes a colon character
// before the first occurrence of a slash character. Note that,
// "protocol" is the field which holds this URLs protocol.
int index;
try {
index = spec.indexOf(':');
} catch (NullPointerException e) {
throw new MalformedURLException(e.toString());
}
int startIPv6Addr = spec.indexOf('[');
if (index >= 0) {
if ((startIPv6Addr == -1) || (index < startIPv6Addr)) {
protocol = spec.substring(0, index);
// According to RFC 2396 scheme part should match
// the following expression:
// alpha *( alpha | digit | "+" | "-" | "." )
char c = protocol.charAt(0);
boolean valid = ('a' <= c && c <= 'z') || ('A' <= c && c <= 'Z');
for (int i = 1; valid && (i < protocol.length()); i++) {
c = protocol.charAt(i);
valid =
('a' <= c && c <= 'z')
|| ('A' <= c && c <= 'Z')
|| ('0' <= c && c <= '9')
|| (c == '+')
|| (c == '-')
|| (c == '.');
}
if (!valid) {
protocol = null;
index = -1;
} else {
// Ignore case in protocol names.
// Scheme is defined by ASCII characters.
protocol = protocol.toLowerCase();
}
}
}
if (protocol != null) {
// If the context was specified, and it had the same protocol
// as the spec, then fill in the receiver's slots from the values
// in the context but still allow them to be over-ridden later
// by the values in the spec.
if (context != null && protocol.equals(context.getProtocol())) {
String cPath = context.getPath();
if (cPath != null && cPath.startsWith("/")) {
set(
protocol,
context.getHost(),
context.getPort(),
context.getAuthority(),
context.getUserInfo(),
cPath,
context.getQuery(),
null);
}
}
} else {
// If the spec did not include a protocol, then the context
// *must* be specified. Fill in the receiver's slots from the
// values in the context, but still allow them to be over-ridden
// by the values in the ("relative") spec.
if (context == null) {
throw new MalformedURLException("Protocol not found: " + spec);
}
set(
context.getProtocol(),
context.getHost(),
context.getPort(),
context.getAuthority(),
context.getUserInfo(),
context.getPath(),
context.getQuery(),
null);
}
if (port < -1) {
throw new MalformedURLException("Port out of range: " + port);
}
}