/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 org.apache.nutch.net;
import java.util.ArrayList;
import java.util.HashMap;
import org.apache.nutch.plugin.Extension;
import org.apache.nutch.plugin.ExtensionPoint;
import org.apache.nutch.plugin.PluginRuntimeException;
import org.apache.nutch.plugin.PluginRepository;
import org.apache.hadoop.conf.Configuration;
/** Creates and caches {@link URLFilter} implementing plugins.*/
public class URLFilters {
public static final String URLFILTER_ORDER = "urlfilter.order";
private URLFilter[] filters;
public URLFilters(Configuration conf) {
String order = conf.get(URLFILTER_ORDER);
this.filters = (URLFilter[]) conf.getObject(URLFilter.class.getName());
if (this.filters == null) {
String[] orderedFilters = null;
if (order != null && !order.trim().equals("")) {
orderedFilters = order.split("\\s+");
}
try {
ExtensionPoint point = PluginRepository.get(conf).getExtensionPoint(
URLFilter.X_POINT_ID);
if (point == null)
throw new RuntimeException(URLFilter.X_POINT_ID + " not found.");
Extension[] extensions = point.getExtensions();
HashMap filterMap = new HashMap();
for (int i = 0; i < extensions.length; i++) {
Extension extension = extensions[i];
URLFilter filter = (URLFilter) extension.getExtensionInstance();
if (!filterMap.containsKey(filter.getClass().getName())) {
filterMap.put(filter.getClass().getName(), filter);
}
}
if (orderedFilters == null) {
conf.setObject(URLFilter.class.getName(), filterMap.values().toArray(
new URLFilter[0]));
} else {
ArrayList filters = new ArrayList();
for (int i = 0; i < orderedFilters.length; i++) {
URLFilter filter = (URLFilter) filterMap.get(orderedFilters[i]);
if (filter != null) {
filters.add(filter);
}
}
conf.setObject(URLFilter.class.getName(), filters
.toArray(new URLFilter[filters.size()]));
}
} catch (PluginRuntimeException e) {
throw new RuntimeException(e);
}
this.filters = (URLFilter[]) conf.getObject(URLFilter.class.getName());
}
}
/** Run all defined filters. Assume logical AND. */
public String filter(String urlString) throws URLFilterException {
for (int i = 0; i < this.filters.length; i++) {
if (urlString == null)
return null;
urlString = this.filters[i].filter(urlString);
}
return urlString;
}
}