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////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Copyright (c) 2018-2022 Saxonica Limited
// This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.
// If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
// This Source Code Form is "Incompatible With Secondary Licenses", as defined by the Mozilla Public License, v. 2.0.
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
package net.sf.saxon.lib;
import net.sf.saxon.Configuration;
import net.sf.saxon.functions.ResolveURI;
import net.sf.saxon.trans.XPathException;
import javax.xml.transform.Source;
import javax.xml.transform.TransformerException;
import javax.xml.transform.stream.StreamSource;
import java.net.URISyntaxException;
import java.util.ArrayList;
import java.util.List;
/**
* 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.
* It relies on location hints being supplied in the "import module" declaration, and attempts
* to locate a module by dereferencing the URI given as the location hint. It accepts standard
* URIs recognized by the Java URL class, including the jar URI scheme; it also
* accepts classpath URIs as defined in the Spring framework.
*/
public class StandardModuleURIResolver implements ModuleURIResolver {
Configuration config = null;
/**
* Create a StandardModuleURIResolver. If this constructor is used, a configuration must
* be supplied in a subsequent call. The constructor is provided to allow instantiation
* from a Configuration file.
*/
public StandardModuleURIResolver() {
}
/**
* Create a StandardModuleURIResolver, with a supplied configuration
* @param config the Saxon Configuration object
*/
public StandardModuleURIResolver(Configuration config) {
this.config = config;
}
/**
* Set the Configuration that this resolver uses. Has no effect if the configuration
* has already been supplied by the constructor.
* @param config the Saxon Configuration object
*/
public void setConfiguration(Configuration config) {
if (this.config == null) {
this.config = config;
}
}
/**
* Resolve a module URI and associated location hints.
* The logic of this is as follows:
*
* - First, call the configuration-level ResourceResolver to resolve the module URI
* as a namespace (via the method resolveModuleURI, which can be overridden in a subclass).
*
* - If this returns null and there are no location hints, throw XQST0059.
* - Otherwise attempt to resolve each of the supplied location hints in turn,
* using first the configuration-level ResourceResolver and then the fallback DirectResourceResolver,
* via the method resolveLocationHint, which can be overridden in a subclass. Return an array containing
* any non-null results; if there are none, throw XQST0059.
*
*
* @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
*/
@Override
public StreamSource[] resolve(String moduleURI, String baseURI, String[] locations) throws XPathException {
if (config == null) {
throw new NullPointerException("No Configuration available in StandardModuleResolver");
}
StreamSource source = resolveModuleURI(moduleURI, baseURI);
if (source != null) {
return new StreamSource[]{source};
}
if (locations.length == 0) {
XPathException err = new XPathException("Cannot locate module for namespace " + moduleURI);
err.setErrorCode("XQST0059");
err.setIsStaticError(true);
throw err;
}
// One or more locations given: import modules from all these locations
List moduleSources = new ArrayList<>();
for (String hint : locations) {
StreamSource ss = resolveLocationHint(baseURI, hint);
if (ss != null) {
moduleSources.add(ss);
}
}
return moduleSources.toArray(new StreamSource[]{});
}
/**
* Attempt to resolve the module namespace URI without the help of location hints.
* @param moduleURI the namespace URI of the module being imported
* @param baseURI the base URI of the module containing the "import module" declaration
* @return a StreamSource delivering the contents of the module.
*/
protected StreamSource resolveModuleURI(String moduleURI, String baseURI) {
try {
Source source = null;
if (config != null) {
ResourceRequest rr = new ResourceRequest();
rr.uri = moduleURI;
rr.uriIsNamespace = true;
rr.baseUri = baseURI;
rr.nature = ResourceRequest.XQUERY_NATURE;
source = config.getResourceResolver().resolve(rr);
}
if (source != null) {
return toStreamSource(source);
}
} catch (TransformerException e) {
// nevermind
}
return null;
}
private StreamSource toStreamSource(Source src) {
return (StreamSource)src; // TODO: handle SAXSource.
}
/**
* Resolve a location hint appearing in an "import module" declaration
* @param baseURI the base URI of the "import module" declaration
* @param locationHint the location hint, as written
* @return either a StreamSource representing the content of the module, or null
* @throws XPathException if the URI is invalid or can't be resolved (but not if the
* module simply doesn't exist at that location)
*/
protected StreamSource resolveLocationHint(String baseURI, String locationHint) throws XPathException {
ResourceRequest rr = new ResourceRequest();
rr.baseUri = baseURI;
rr.relativeUri = locationHint;
rr.nature = ResourceRequest.XQUERY_NATURE;
try {
rr.uri = ResolveURI.makeAbsolute(rr.relativeUri, baseURI).toString();
return (StreamSource) rr.resolve(config.getResourceResolver(), new DirectResourceResolver(config));
} catch (URISyntaxException err) {
XPathException se = new XPathException("Cannot resolve relative URI " + rr.relativeUri, err);
se.setErrorCode("XQST0059");
se.setIsStaticError(true);
throw se;
}
}
// /**
// * 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
// */
//
// /*@NotNull*/
// protected StreamSource getQuerySource(URI absoluteURI)
// throws XPathException {
//
// String encoding = null;
// try {
// InputStream is = null;
// if ("classpath".equals(absoluteURI.getScheme())) {
// String path = absoluteURI.getPath();
// if (config != null) {
// is = config.getDynamicLoader().getResourceAsStream(path);
// }
// if (is == null) {
// XPathException se = new XPathException("Cannot locate module " + path + " on class path");
// se.setErrorCode("XQST0059");
// se.setIsStaticError(true);
// throw se;
// }
// } else {
// URLConnection connection = Loader.urlConnection(absoluteURI.toURL());
// is = connection.getInputStream();
//
// // Get any external (HTTP) encoding label.
// String contentType;
//
// // 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();
// }
// }
// }
// }
//
// if (!is.markSupported()) {
// is = new BufferedInputStream(is);
// }
//
//
// StreamSource ss = new StreamSource();
// if (encoding == null) {
// ss.setInputStream(is);
// } else {
// ss.setReader(new InputStreamReader(is, encoding));
// }
// ss.setSystemId(absoluteURI.toString());
// return ss;
// } catch (IOException err) {
// XPathException se = new XPathException(err);
// se.setErrorCode("XQST0059");
// se.setIsStaticError(true);
// throw se;
// }
//
// }
}