package net.sf.saxon.query;
import net.sf.saxon.Configuration;
import net.sf.saxon.Platform;
import net.sf.saxon.trans.XPathException;
import javax.xml.transform.stream.StreamSource;
import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;
import java.net.URLConnection;
/**
* This class is the standard ModuleURIResolver used to implement the "import module" declaration
* in a Query Prolog. It is used when no user-defined ModuleURIResolver has been specified, or when
* the user-defined ModuleURIResolver decides to delegate to the standard ModuleURIResolver.
*
* @author Michael H. Kay
*/
public class StandardModuleURIResolver implements ModuleURIResolver {
private static StandardModuleURIResolver THE_INSTANCE = new StandardModuleURIResolver();
/**
* Get the singular instance of this class
* @return the singular instance of this class
*/
public static StandardModuleURIResolver getInstance() {
return THE_INSTANCE;
}
/**
* Create a StandardModuleURIResolver
*/
protected StandardModuleURIResolver() {
}
/**
* Resolve a module URI and associated location hints.
* @param moduleURI The module namespace URI of the module to be imported; or null when
* loading a non-library module.
* @param baseURI The base URI of the module containing the "import module" declaration;
* null if no base URI is known
* @param locations The set of URIs specified in the "at" clause of "import module",
* which serve as location hints for the module
* @return an array of StreamSource objects each identifying the contents of a module to be
* imported. Each StreamSource must contain a
* non-null absolute System ID which will be used as the base URI of the imported module,
* and either an InputSource or a Reader representing the text of the module.
* @throws XPathException (error XQST0059) if the module cannot be located
*/
public StreamSource[] resolve(String moduleURI, String baseURI, String[] locations) throws XPathException {
if (locations.length == 0) {
XPathException err = new XPathException("Cannot locate module for namespace " + moduleURI);
err.setErrorCode("XQST0059");
err.setIsStaticError(true);
throw err;
} else {
// One or more locations given: import modules from all these locations
Platform platform = Configuration.getPlatform();
StreamSource[] sources = new StreamSource[locations.length];
for (int m=0; m<locations.length; m++) {
String href = locations[m];
URI absoluteURI;
try {
absoluteURI = platform.makeAbsolute(href, baseURI);
} catch (URISyntaxException err) {
XPathException se = new XPathException("Cannot resolve relative URI " + href, err);
se.setErrorCode("XQST0059");
se.setIsStaticError(true);
throw se;
}
sources[m] = getQuerySource(absoluteURI);
}
return sources;
}
}
/**
* Get a StreamSource object representing the source of a query, given its URI.
* This method attempts to discover the encoding by reading any HTTP headers.
* If the encoding can be determined, it returns a StreamSource containing a Reader that
* performs the required decoding. Otherwise, it returns a StreamSource containing an
* InputSource, leaving the caller to sort out encoding problems.
* @param absoluteURI the absolute URI of the source query
* @return a StreamSource containing a Reader or InputSource, as well as a systemID representing
* the base URI of the query.
* @throws XPathException if the URIs are invalid or cannot be resolved or dereferenced, or
* if any I/O error occurs
*/
protected StreamSource getQuerySource(URI absoluteURI)
throws XPathException {
try {
InputStream is;
URL absoluteURL = absoluteURI.toURL();
URLConnection connection = absoluteURL.openConnection();
connection.connect();
is = connection.getInputStream();
if (!is.markSupported()) {
is = new BufferedInputStream(is);
}
// Get any external (HTTP) encoding label.
String contentType;
String encoding = null;
// The file:// URL scheme gives no useful information...
if (!"file".equals(connection.getURL().getProtocol())) {
// Use the contentType from the HTTP header if available
contentType = connection.getContentType();
if (contentType != null) {
int pos = contentType.indexOf("charset");
if (pos>=0) {
pos = contentType.indexOf('=', pos + 7);
if (pos>=0) {
contentType = contentType.substring(pos + 1);
}
if ((pos = contentType.indexOf(';')) > 0) {
contentType = contentType.substring(0, pos);
}
// attributes can have comment fields (RFC 822)
if ((pos = contentType.indexOf('(')) > 0) {
contentType = contentType.substring(0, pos);
}
// ... and values may be quoted
if ((pos = contentType.indexOf('"')) > 0) {
contentType = contentType.substring(pos + 1,
contentType.indexOf('"', pos + 2));
}
encoding = contentType.trim();
}
}
}
StreamSource ss = new StreamSource();
if (encoding == null) {
ss.setInputStream(is);
} else {
ss.setReader(new InputStreamReader(is, encoding));
}
ss.setSystemId(absoluteURL.toString());
return ss;
} catch (IOException err) {
XPathException se = new XPathException(err);
se.setErrorCode("XQST0059");
se.setIsStaticError(true);
throw se;
}
}
}
//
// The contents of this file are subject to the Mozilla Public License Version 1.0 (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.mozilla.org/MPL/
//
// Software distributed under the License is distributed on an "AS IS" basis,
// WITHOUT WARRANTY OF ANY KIND, either express or implied.
// See the License for the specific language governing rights and limitations under the License.
//
// The Original Code is: all this file.
//
// The Initial Developer of the Original Code is Michael H. Kay
//
// Portions created by (your name) are Copyright (C) (your legal entity). All Rights Reserved.
//
// Contributor(s): none.
//