Java tutorial
/******************************************************************************* * Copyright 2016 JSL Solucoes LTDA - https://jslsolucoes.com * * Licensed 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 com.jslsolucoes.tagria.lib.servlet; import java.io.IOException; import java.io.InputStream; import java.text.SimpleDateFormat; import java.util.Locale; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.jsp.jstl.core.Config; import org.apache.commons.codec.digest.DigestUtils; import org.apache.commons.io.IOUtils; import org.joda.time.DateTime; import org.joda.time.Seconds; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.google.gson.Gson; import com.google.gson.GsonBuilder; import com.jslsolucoes.tagria.lib.grid.exporter.impl.CsvExporter; import com.jslsolucoes.tagria.lib.grid.exporter.impl.ExcelExporter; import com.jslsolucoes.tagria.lib.grid.exporter.impl.PdfExporter; import com.jslsolucoes.tagria.lib.grid.exporter.impl.XmlExporter; import com.jslsolucoes.tagria.lib.grid.exporter.model.Table; import com.jslsolucoes.tagria.lib.util.TagUtil; @SuppressWarnings("serial") @WebServlet(name = "tagria", urlPatterns = "/tagria/*", loadOnStartup = 1) public class Tagria extends HttpServlet { private static final Integer CACHE_EXPIRES_DAY = 365; private static Logger logger = LoggerFactory.getLogger(Tagria.class); @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String uri = request.getRequestURI().replaceAll(";jsessionid=.*", ""); String etag = DigestUtils.sha256Hex(uri); if (uri.endsWith("blank")) { response.setStatus(HttpServletResponse.SC_OK); return; } if (uri.endsWith("locale")) { Config.set(request.getSession(), Config.FMT_LOCALE, Locale.forLanguageTag(request.getParameter("locale"))); response.setStatus(HttpServletResponse.SC_OK); return; } if (request.getHeader("If-None-Match") != null && etag.equals(request.getHeader("If-None-Match"))) { response.setStatus(HttpServletResponse.SC_NOT_MODIFIED); return; } String charset = "utf-8"; if (TagUtil.getInitParam(TagriaConfigParameter.ENCODING) != null) { charset = TagUtil.getInitParam(TagriaConfigParameter.ENCODING); } response.setCharacterEncoding(charset); try { DateTime today = new DateTime(); DateTime expires = new DateTime().plusDays(CACHE_EXPIRES_DAY); if (uri.endsWith(".css")) { response.setContentType("text/css"); } else if (uri.endsWith(".js")) { response.setContentType("text/javascript"); } else if (uri.endsWith(".png")) { response.setContentType("image/png"); } SimpleDateFormat sdf = new SimpleDateFormat("E, dd MMM yyyy HH:mm:ss 'GMT'", Locale.ENGLISH); if (Boolean.valueOf(TagUtil.getInitParam(TagriaConfigParameter.CDN_ENABLED))) { response.setHeader(HttpHeaderParameter.ACCESS_CONTROL_ALLOW_ORIGIN.getName(), "*"); } response.setHeader(HttpHeaderParameter.ETAG.getName(), etag); response.setHeader(HttpHeaderParameter.EXPIRES.getName(), sdf.format(expires.toDate())); response.setHeader(HttpHeaderParameter.CACHE_CONTROL.getName(), "public,max-age=" + Seconds.secondsBetween(today, expires).getSeconds()); String url = "/com/jslsolucoes" + uri.replaceFirst(request.getContextPath(), "").replaceAll(";jsessionid=.*", ""); InputStream in = getClass().getResourceAsStream(url); IOUtils.copy(in, response.getOutputStream()); in.close(); } catch (Exception exception) { logger.error("Could not load resource", exception); response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR); } } @Override protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { try { Gson gson = new GsonBuilder().create(); String json = request.getParameter("json"); String type = request.getParameter("type"); Table table = gson.fromJson(json, Table.class); response.setHeader("Content-Disposition", "attachment; filename=grid." + type); if ("pdf".equals(type)) { response.setContentType("application/pdf"); PdfExporter exporter = new PdfExporter(table); exporter.doExport(response.getOutputStream()); } else if ("csv".equals(type)) { response.setContentType("text/csv"); CsvExporter exporter = new CsvExporter(table); exporter.doExport(response.getOutputStream()); } else if ("xml".equals(type)) { response.setContentType("text/xml"); XmlExporter exporter = new XmlExporter(table); exporter.doExport(response.getOutputStream()); } else if ("xls".equals(type)) { response.setContentType("application/vnd.ms-excel"); ExcelExporter exporter = new ExcelExporter(table); exporter.doExport(response.getOutputStream()); } } catch (Exception exception) { logger.error("Could not export data", exception); response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR); } } }