edu.cornell.mannlib.vitro.webapp.servlet.ConceptSearchServlet.java Source code

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Here is the source code for edu.cornell.mannlib.vitro.webapp.servlet.ConceptSearchServlet.java

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/* $This file is distributed under the terms of the license in /doc/license.txt$ */

package edu.cornell.mannlib.vitro.webapp.servlet;

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

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.lang.StringUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;

import edu.cornell.mannlib.semservices.bo.Concept;
import edu.cornell.mannlib.semservices.bo.ConceptInfo;
import edu.cornell.mannlib.semservices.bo.SemanticServicesError;
import edu.cornell.mannlib.vitro.webapp.controller.VitroHttpServlet;
import edu.cornell.mannlib.vitro.webapp.controller.VitroRequest;
import edu.cornell.mannlib.vitro.webapp.utils.ConceptSearchService.ConceptSearchServiceUtils;

public class ConceptSearchServlet extends VitroHttpServlet {

    private static final long serialVersionUID = 1L;
    private static final Log log = LogFactory.getLog(ConceptSearchServlet.class);

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        super.doGet(req, resp);
    }

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        super.doGet(req, resp);
        VitroRequest vreq = new VitroRequest(req);

        try {
            ServletContext ctx = vreq.getSession().getServletContext();
            //Captures both concept list and any errors if they exist
            ConceptInfo conceptInfo = new ConceptInfo();
            conceptInfo.setSemanticServicesError(null);

            //Json output should be written out
            List<Concept> results = null;
            try {
                results = ConceptSearchServiceUtils.getSearchResults(ctx, vreq);
            } catch (Exception ex) {
                SemanticServicesError semanticServicesError = new SemanticServicesError("Exception encountered ",
                        ex.getMessage(), "fatal");
                log.error("An error occurred retrieving search results", ex);
                conceptInfo.setSemanticServicesError(semanticServicesError);
            }
            conceptInfo.setConceptList(results);

            String json = renderJson(conceptInfo);

            json = StringUtils.replaceChars(json, "\r\t\n", "");
            PrintWriter writer = resp.getWriter();
            resp.setContentType("application/json");
            writer.write(json);
            writer.close();

        } catch (Exception ex) {
            log.warn(ex, ex);
        }
    }

    protected String renderJson(ConceptInfo conceptInfo) {

        ObjectMapper mapper = new ObjectMapper();
        try {
            return mapper.writeValueAsString(conceptInfo);
        } catch (JsonProcessingException e) {
            // TODO Auto-generated catch block
            log.error("An error occurred in rendering conceptInfo as json ", e);
            return null;
        }
    }

}