org.apache.nutch.webapp.common.BaseSearch.java Source code

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Here is the source code for org.apache.nutch.webapp.common.BaseSearch.java

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/*
 * 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.webapp.common;

import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.nutch.plugin.Extension;
import org.apache.nutch.plugin.ExtensionPoint;
import org.apache.nutch.webapp.extension.PostSearchExtensionPoint;
import org.apache.nutch.webapp.extension.PreSearchExtensionPoint;
import org.apache.nutch.webapp.extension.SearchExtensionPoint;

public class BaseSearch {

    public static final Log LOG = LogFactory.getLog(BaseSearch.class);

    protected PreSearchExtensionPoint[] presearch;

    protected SearchExtensionPoint[] search;

    protected PostSearchExtensionPoint[] postsearch;

    protected Collection setup(String xPoint, Configuration conf) {
        LOG.info("setting up:" + xPoint);

        HashMap filters = new HashMap();
        try {
            ExtensionPoint point = serviceLocator.getPluginRepository().getExtensionPoint(xPoint);
            if (point != null) {
                Extension[] extensions = point.getExtensions();
                for (int i = 0; i < extensions.length; i++) {
                    Extension extension = extensions[i];
                    Object extensionInstance = extension.getExtensionInstance();
                    if (!filters.containsKey(extensionInstance.getClass().getName())) {
                        filters.put(extensionInstance.getClass().getName(), extensionInstance);
                    }
                }
                return filters.values();
            }
        } catch (Exception e) {
            LOG.info("Error setting up extensions :" + e);
        }
        return Collections.EMPTY_LIST;

    }

    private ServiceLocator serviceLocator;

    /**
     * Construct new BaseSearch object
     */
    public BaseSearch(ServiceLocator locator) {
        this.serviceLocator = locator;
        Collection pre = getPreSearchExtensions(serviceLocator.getConfiguration());
        presearch = new PreSearchExtensionPoint[pre.size()];
        pre.toArray(presearch);

        Collection searchC = getSearchExtensions(serviceLocator.getConfiguration());
        search = new SearchExtensionPoint[searchC.size()];
        searchC.toArray(search);

        Collection post = getPostSearchExtensions(serviceLocator.getConfiguration());
        postsearch = new PostSearchExtensionPoint[post.size()];
        post.toArray(postsearch);
    }

    public Collection getPreSearchExtensions(Configuration conf) {
        if (conf.getObject(PreSearchExtensionPoint.X_POINT_ID) == null) {
            conf.setObject(PreSearchExtensionPoint.X_POINT_ID, setup(PreSearchExtensionPoint.X_POINT_ID, conf));
        }

        return (Collection) conf.getObject(PreSearchExtensionPoint.X_POINT_ID);
    }

    public Collection getSearchExtensions(Configuration conf) {
        if (conf.getObject(SearchExtensionPoint.X_POINT_ID) == null) {
            conf.setObject(SearchExtensionPoint.X_POINT_ID, setup(SearchExtensionPoint.X_POINT_ID, conf));
        }
        return (Collection) conf.getObject(SearchExtensionPoint.X_POINT_ID);
    }

    public Collection getPostSearchExtensions(Configuration conf) {
        if (conf.getObject(PostSearchExtensionPoint.X_POINT_ID) == null) {
            conf.setObject(PostSearchExtensionPoint.X_POINT_ID, setup(PostSearchExtensionPoint.X_POINT_ID, conf));
        }
        return (Collection) conf.getObject(PostSearchExtensionPoint.X_POINT_ID);
    }

    /**
     * Call plugins participating PreSearch activities.
     */
    void callPreSearch(ServiceLocator locator) {
        LOG.info("presearch");
        for (int i = 0; i < presearch.length; i++) {
            presearch[i].doPreSearch(serviceLocator);
        }
    }

    /**
     * Call plugins participating Search activities.
     */
    void callSearch() {
        for (int i = 0; i < search.length; i++) {
            search[i].doSearch(serviceLocator);
        }
    }

    /**
     * Call plugins participating postSearch activities.
     */
    void callPostSearch(ServiceLocator locator) {
        LOG.info("postsearch");
        for (int i = 0; i < postsearch.length; i++) {
            postsearch[i].doPostSearch(serviceLocator);
        }
    }

    /**
     * Entry point to execute the search.
     */
    public void doSearch() {
        // create context
        callPreSearch(serviceLocator);
        serviceLocator.getSearch().performSearch();
        // callSearch();
        callPostSearch(serviceLocator);
    }
}