/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2010-2011, Open Source Geospatial Foundation (OSGeo)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*/
package org.geotools.xml;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.logging.Logger;
import org.apache.xml.resolver.Catalog;
import org.apache.xml.resolver.CatalogManager;
/**
* Support for application schema resolution in an <a
* href="http://www.oasis-open.org/committees/entity/spec-2001-08-06.html">OASIS Catalog</a> (with
* URI resolution semantics).
*
* @author Ben Caradoc-Davies (CSIRO Earth Science and Resource Engineering)
* @see
*
*
* @source $URL$
*/
public class AppSchemaCatalog {
private static final Logger LOGGER = org.geotools.util.logging.Logging
.getLogger(AppSchemaCatalog.class.getPackage().getName());
private final Catalog catalog;
/**
* Use {@link #build(URL)} to construct an instance.
*
* @param catalog
*/
private AppSchemaCatalog(Catalog catalog) {
this.catalog = catalog;
}
/**
* Return schema location resolved in the catalog if possible. <tt>rewriteURI</tt> semantics are
* used.
*
* @param location
* typically an absolute http/https URL.
* @return null if location not found in the catalog
*/
public String resolveLocation(String location) {
String resolvedLocation = null;
try {
resolvedLocation = catalog.resolveURI(location);
} catch (Exception e) {
throw new RuntimeException(e);
}
if (resolvedLocation != null) {
InputStream input = null;
try {
// verify existence of resource
// could be a file, jar resource, or other
input = (new URL(resolvedLocation)).openStream();
// catalog hit
LOGGER.fine("Catalog resolved " + location + " to " + resolvedLocation);
} catch (IOException e) {
// catalog miss
LOGGER.fine("Catalog did not resolve " + location + " to " + resolvedLocation
+ " despite matching catalog entry because an error occurred: "
+ e.getMessage());
resolvedLocation = null;
} finally {
if (input != null) {
try {
input.close();
} catch (IOException e) {
// we tried
}
}
}
}
return resolvedLocation;
}
/**
* Build a private {@link Catalog}, that is, not the static instance that {@link CatalogManager}
* returns by default.
*
* <p>
*
* Care must be taken to use only private {@link Catalog} instances if there will ever be more
* than one OASIS Catalog used in a single class loader (i.e. a single maven test run),
* otherwise {@link Catalog} contents will be an amalgam of the entries of both OASIS Catalog
* files, with likely unintended or incorrect results. See GEOT-2497.
*
* @param catalogLocation
* URL of OASIS Catalog
* @return a private Catalog
*/
static Catalog buildPrivateCatalog(URL catalogLocation) {
CatalogManager catalogManager = new CatalogManager();
catalogManager.setUseStaticCatalog(false);
catalogManager.setVerbosity(0);
catalogManager.setIgnoreMissingProperties(true);
Catalog catalog = catalogManager.getCatalog();
try {
catalog.parseCatalog(catalogLocation);
} catch (IOException e) {
throw new RuntimeException("Error trying to load OASIS catalog from URL "
+ catalogLocation.toString(), e);
}
return catalog;
}
/**
* Build an catalog using the given OASIS Catalog file URL.
*
* @param catalogLocation
* local file URL to an OASIS cCtalog
* @return
*/
public static AppSchemaCatalog build(URL catalogLocation) {
return new AppSchemaCatalog(buildPrivateCatalog(catalogLocation));
}
}