/*
* Copyright 2009 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.google.gwt.uibinder.rebind;
import com.google.gwt.core.ext.TreeLogger;
import com.google.gwt.dev.resource.Resource;
import com.google.gwt.dev.resource.ResourceOracle;
import com.google.gwt.dev.util.Util;
import com.google.gwt.dev.util.collect.Sets;
import org.xml.sax.EntityResolver;
import org.xml.sax.InputSource;
import java.io.IOException;
import java.io.InputStream;
import java.io.StringReader;
import java.util.Collections;
import java.util.Set;
/**
* Makes the sax xml parser use the {@link ResourceOracle}.
* <p>
* Does special case handling of GWT specific DTDs to be fetched from our
* download site. If the requested uri starts with
* <code>http://dl.google.com/gwt/DTD/</code> (or one or two others), provides
* the contents from a built in resource rather than allowing sax to make a
* network request.
*/
class GwtResourceEntityResolver implements EntityResolver {
private static final Set<String> EXTERNAL_PREFIXES = Collections.unmodifiableSet(Sets.create(new String[] {
"http://google-web-toolkit.googlecode.com/files/",
"http://dl.google.com/gwt/DTD/", "https://dl-ssl.google.com/gwt/DTD/"}));
private static final String RESOURCES = "com/google/gwt/uibinder/resources/";
private String pathBase;
private final ResourceOracle resourceOracle;
private final TreeLogger logger;
public GwtResourceEntityResolver(TreeLogger logger, ResourceOracle resourceOracle,
String pathBase) {
this.logger = logger;
this.resourceOracle = resourceOracle;
this.pathBase = pathBase;
}
@Override
public InputSource resolveEntity(String publicId, String systemId) {
String matchingPrefix = findMatchingPrefix(systemId);
Resource resource = null;
if (matchingPrefix != null) {
resource =
resourceOracle.getResource(RESOURCES + systemId.substring(matchingPrefix.length()));
}
if (resource == null) {
resource = resourceOracle.getResource(pathBase + systemId);
}
if (resource != null) {
String content;
try {
InputStream resourceStream = resource.openContents();
content = Util.readStreamAsString(resourceStream);
} catch (IOException ex) {
logger.log(TreeLogger.ERROR, "Error reading resource: " + resource.getLocation());
throw new RuntimeException(ex);
}
InputSource inputSource = new InputSource(new StringReader(content));
inputSource.setPublicId(publicId);
inputSource.setSystemId(resource.getPath());
return inputSource;
}
/*
* Let Sax find it on the interweb.
*/
return null;
}
private String findMatchingPrefix(String systemId) {
for (String prefix : EXTERNAL_PREFIXES) {
if (systemId.startsWith(prefix)) {
return prefix;
}
}
return null;
}
}