D-Net

package eu.dnetlib.data.search.web.servlet;

import eu.dnetlib.api.data.SearchService;

import eu.dnetlib.data.search.app.SearchServiceImpl;

import eu.dnetlib.domain.data.FormattedSearchResult;

import org.apache.commons.lang.IncompleteArgumentException;

import org.apache.commons.lang.StringEscapeUtils;

import org.apache.log4j.Logger;

import org.springframework.context.ApplicationContext;

import org.springframework.web.context.support.WebApplicationContextUtils;

import javax.servlet.ServletConfig;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import java.io.PrintWriter;

import java.util.ArrayList;

import java.util.Collection;

@SuppressWarnings("serial")

public class SearchServlet extends HttpServlet{

	private SearchServiceImpl searchService = null;

	private ApplicationContext context = null;

	private static Logger logger = Logger.getLogger(SearchService.class); 

	public void init(ServletConfig config) throws ServletException {

		super.init(config);

		context = WebApplicationContextUtils.getWebApplicationContext(getServletContext());

		searchService = (SearchServiceImpl) context.getBean("searchService");

	}

	@Override

	public void doGet(HttpServletRequest request, HttpServletResponse response) {		

		PrintWriter writer = null;

		FormattedSearchResult formattedSearchResult = null;

		String action = request.getParameter("action");

		if (action == null) {

			throw new UnsupportedOperationException("Undefined action.");

		}

		String query = request.getParameter("query");

		if (query == null) {

			throw new IncompleteArgumentException("Undefined query. Search request");

		}

		String format = (request.getParameter("format") != null) ?

				request.getParameter("format") : "xml";

		String locale = request.getParameter("locale");

		int page = readParameter(request, "page", 1); 					

		int size = readParameter(request, "size", 10);

		String sTransformer = request.getParameter("sTransformer");

		String rTransformer = request.getParameter("rTransformer");

		Collection<String> fields = readParameter(request, "fields");

		response.setContentType("text/xml;charset=UTF-8");

		try {			

			writer = response.getWriter();	

			if(action.equals("search")) {				

				if (sTransformer == null) {

					throw new IncompleteArgumentException("Undefined search transformer. Search request");

				}				

				formattedSearchResult = searchService.search(query, sTransformer, format, locale, page, size);

			} else if(action.equals("refine")) {

				if(rTransformer == null) {

					throw new IncompleteArgumentException("Undefined refine transformer. Refine request");

				}

				if(fields == null) {

					throw new IncompleteArgumentException("Undefined refine fields. Refine request");

				}

				formattedSearchResult = searchService.refine(query, rTransformer, format, locale, fields);

			} else if(action.equals("searchNrefine")) {								

				if(sTransformer == null) {

					throw new IncompleteArgumentException("Undefined search transformer. Search and Refine request");

				}

				if(rTransformer == null) {

					throw new IncompleteArgumentException("Undefined refine transformer. Search and Refine request");

				}

				if(fields == null) {

					throw new IncompleteArgumentException("Undefined refine fields. Search and Refine request");

				}

				formattedSearchResult = searchService.searchNrefine(query, sTransformer, rTransformer, format, locale, page, size, fields);

			} else {

				throw new UnsupportedOperationException("The action " + action + " is not supported.");

			}

			writer.append(formattedSearchResult.getFormattedResult());	

		} catch (Exception e) {			

			writer.append("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");

			writer.append("<error>");

			writer.append("<exception>").append(StringEscapeUtils.escapeXml(e.getClass().getName())).append("</exception>");

			if (e.getMessage() != null) {

				writer.append("<message>").append(StringEscapeUtils.escapeXml(e.getMessage())).append("</message>");

			}

			if (e.getCause() != null) {

				writer.append("<cause>").append(StringEscapeUtils.escapeXml(e.getCause().toString())).append("</cause>");

			}

			StackTraceElement[] trace = e.getStackTrace();

			writer.append("<trace>");

			for (int i = 0; i < trace.length; i++) {

				writer.append(StringEscapeUtils.escapeXml(trace[i].toString())).append("\n");

			}

			writer.append("</trace>");

			writer.append("</error>");

		} finally {

			writer.close();

		}

	}

	private Collection<String> readParameter(HttpServletRequest request, String parameterName) {

		Collection<String> fields = null;

		String[] paramfields = request.getParameterValues(parameterName);

		if (paramfields != null) {

			fields = new ArrayList<String>(); 

			for (int i=0; i<paramfields.length; i++)

				fields.add(paramfields[i]);

		}

		return fields;

	}

	public int readParameter(HttpServletRequest request, String parameterName, int defaultValue) {

		String param = request.getParameter(parameterName);

		return (param != null)?Integer.parseInt(param):defaultValue;

	}

}