de.fme.topx.webscript.TopXSearchWebscript.java Source code

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Here is the source code for de.fme.topx.webscript.TopXSearchWebscript.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 de.fme.topx.webscript;

import java.io.IOException;
import java.util.List;

import javax.servlet.http.HttpServletResponse;

import org.apache.commons.lang.StringUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.codehaus.jackson.map.ObjectMapper;
import org.springframework.extensions.webscripts.AbstractWebScript;
import org.springframework.extensions.webscripts.WebScriptRequest;
import org.springframework.extensions.webscripts.WebScriptResponse;

import de.fme.topx.component.TopXSearchComponent;
import de.fme.topx.model.Node;

/**
 * the search webscript delivers the search results from the
 * {@link TopXSearchComponent} as json response.
 * 
 * @author jgoldhammer
 * 
 */
public class TopXSearchWebscript extends AbstractWebScript {

    private static final String DEFAULT_MAX_ITEMS = "10";
    TopXSearchComponent searchComponent;
    private ObjectMapper mapper;
    private final static Log LOG = LogFactory.getLog(TopXSearchWebscript.class);

    public TopXSearchComponent getSearchComponent() {
        return searchComponent;
    }

    public void setSearchComponent(TopXSearchComponent searchComponent) {
        this.searchComponent = searchComponent;
    }

    public void init() {
        // instance should be cached for performance reasons.
        mapper = new ObjectMapper();
    }

    /**
     * executes the search- checks input parameter, executes the search and
     * sends back the json result.
     * 
     * (non-Javadoc)
     * 
     * @see org.springframework.extensions.webscripts.WebScript#execute(org.springframework.extensions.webscripts.WebScriptRequest,
     *      org.springframework.extensions.webscripts.WebScriptResponse)
     */
    @Override
    public void execute(WebScriptRequest req, WebScriptResponse response) throws IOException {
        // get input parameter
        String queryType = req.getParameter("queryType");
        String parentId = req.getParameter("parentId");
        String maxItems = req.getParameter("maxItems") != null ? req.getParameter("maxItems") : DEFAULT_MAX_ITEMS;
        LOG.debug("Incoming request: queryType=" + queryType + ", parentId=" + parentId + ", maxItems=" + maxItems
                + "");

        if (StringUtils.isBlank(queryType)) {
            response.setStatus(HttpServletResponse.SC_BAD_REQUEST);
        } else {
            try {
                List<Node> results = searchComponent.submitSearch(queryType, maxItems, parentId);
                generateJson(results, response);
            } catch (Throwable e) {
                LOG.error("Encountered exception while searching and generating json ", e);
                response.setStatus(HttpServletResponse.SC_BAD_REQUEST);
            }
        }
    }

    /**
     * generates the json for the list of results.
     * 
     * @param results
     *            the list of nodes
     * @param response
     *            the outputstream where json should write in.
     * @throws IOException
     *             if json generation fails.
     */
    private void generateJson(List<Node> results, WebScriptResponse response) throws IOException {
        mapper.writeValue(response.getOutputStream(), results);
    }

}