Sun, 21 Jun 2020 11:10:30 +0200
smaller issue summary progress bars
/* * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER. * * Copyright 2018 Mike Becker. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * */ package de.uapcore.lightpit; import de.uapcore.lightpit.dao.DataAccessObjects; import de.uapcore.lightpit.dao.postgres.PGDataAccessObjects; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; import java.io.IOException; import java.lang.reflect.*; import java.sql.Connection; import java.sql.SQLException; import java.util.*; import java.util.function.Function; /** * A special implementation of a HTTPServlet which is focused on implementing * the necessary functionality for LightPIT pages. */ public abstract class AbstractLightPITServlet extends HttpServlet { private static final Logger LOG = LoggerFactory.getLogger(AbstractLightPITServlet.class); private static final String SITE_JSP = Functions.jspPath("site"); @FunctionalInterface protected interface SQLFindFunction<K, T> { T apply(K key) throws SQLException; default <V> SQLFindFunction<V, T> compose(Function<? super V, ? extends K> before) throws SQLException { Objects.requireNonNull(before); return (v) -> this.apply(before.apply(v)); } default <V> SQLFindFunction<K, V> andThen(Function<? super T, ? extends V> after) throws SQLException { Objects.requireNonNull(after); return (t) -> after.apply(this.apply(t)); } static <K> Function<K, K> identity() { return (t) -> t; } } /** * Invocation mapping gathered from the {@link RequestMapping} annotations. * <p> * Paths in this map must always start with a leading slash, although * the specification in the annotation must not start with a leading slash. * <p> * The reason for this is the different handling of empty paths in * {@link HttpServletRequest#getPathInfo()}. */ private final Map<HttpMethod, Map<String, Method>> mappings = new HashMap<>(); /** * Returns the name of the resource bundle associated with this servlet. * * @return the resource bundle base name */ protected abstract String getResourceBundleName(); /** * Creates a set of data access objects for the specified connection. * * @param connection the SQL connection * @return a set of data access objects */ private DataAccessObjects createDataAccessObjects(Connection connection) throws SQLException { final var df = (DatabaseFacade) getServletContext().getAttribute(DatabaseFacade.SC_ATTR_NAME); if (df.getSQLDialect() == DatabaseFacade.Dialect.Postgres) { return new PGDataAccessObjects(connection); } throw new AssertionError("Non-exhaustive if-else - this is a bug."); } private ResponseType invokeMapping(Method method, HttpServletRequest req, HttpServletResponse resp, DataAccessObjects dao) throws IOException { try { LOG.trace("invoke {}#{}", method.getDeclaringClass().getName(), method.getName()); final var paramTypes = method.getParameterTypes(); final var paramValues = new Object[paramTypes.length]; for (int i = 0; i < paramTypes.length; i++) { if (paramTypes[i].isAssignableFrom(HttpServletRequest.class)) { paramValues[i] = req; } else if (paramTypes[i].isAssignableFrom(HttpServletResponse.class)) { paramValues[i] = resp; } if (paramTypes[i].isAssignableFrom(DataAccessObjects.class)) { paramValues[i] = dao; } } return (ResponseType) method.invoke(this, paramValues); } catch (InvocationTargetException ex) { LOG.error("invocation of method {}::{} failed: {}", method.getDeclaringClass().getName(), method.getName(), ex.getTargetException().getMessage()); LOG.debug("Details: ", ex.getTargetException()); resp.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, ex.getTargetException().getMessage()); return ResponseType.NONE; } catch (ReflectiveOperationException | ClassCastException ex) { LOG.error("invocation of method {}::{} failed: {}", method.getDeclaringClass().getName(), method.getName(), ex.getMessage()); LOG.debug("Details: ", ex); resp.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, ex.getMessage()); return ResponseType.NONE; } } @Override public void init() throws ServletException { scanForRequestMappings(); LOG.trace("{} initialized", getServletName()); } private void scanForRequestMappings() { try { Method[] methods = getClass().getDeclaredMethods(); for (Method method : methods) { Optional<RequestMapping> mapping = Optional.ofNullable(method.getAnnotation(RequestMapping.class)); if (mapping.isPresent()) { if (!Modifier.isPublic(method.getModifiers())) { LOG.warn("{} is annotated with {} but is not public", method.getName(), RequestMapping.class.getSimpleName() ); continue; } if (Modifier.isAbstract(method.getModifiers())) { LOG.warn("{} is annotated with {} but is abstract", method.getName(), RequestMapping.class.getSimpleName() ); continue; } if (!ResponseType.class.isAssignableFrom(method.getReturnType())) { LOG.warn("{} is annotated with {} but has the wrong return type - 'ResponseType' required", method.getName(), RequestMapping.class.getSimpleName() ); continue; } boolean paramsInjectible = true; for (var param : method.getParameterTypes()) { paramsInjectible &= HttpServletRequest.class.isAssignableFrom(param) || HttpServletResponse.class.isAssignableFrom(param) || DataAccessObjects.class.isAssignableFrom(param); } if (paramsInjectible) { String requestPath = "/" + mapping.get().requestPath(); if (mappings .computeIfAbsent(mapping.get().method(), k -> new HashMap<>()) .putIfAbsent(requestPath, method) != null) { LOG.warn("{} {} has multiple mappings", mapping.get().method(), mapping.get().requestPath() ); } LOG.debug("{} {} maps to {}::{}", mapping.get().method(), requestPath, getClass().getSimpleName(), method.getName() ); } else { LOG.warn("{} is annotated with {} but has the wrong parameters - only HttpServletRequest. HttpServletResponse, and DataAccessObjects are allowed", method.getName(), RequestMapping.class.getSimpleName() ); } } } } catch (SecurityException ex) { LOG.error("Scan for request mappings on declared methods failed.", ex); } } @Override public void destroy() { mappings.clear(); LOG.trace("{} destroyed", getServletName()); } /** * Sets the name of the content page. * <p> * It is sufficient to specify the name without any extension. The extension * is added automatically if not specified. * * @param req the servlet request object * @param pageName the name of the content page * @see Constants#REQ_ATTR_CONTENT_PAGE */ protected void setContentPage(HttpServletRequest req, String pageName) { req.setAttribute(Constants.REQ_ATTR_CONTENT_PAGE, Functions.jspPath(pageName)); } /** * Sets the breadcrumbs menu. * * @param req the servlet request object * @param breadcrumbs the menu entries for the breadcrumbs menu * @see Constants#REQ_ATTR_BREADCRUMBS */ protected void setBreadcrumbs(HttpServletRequest req, List<MenuEntry> breadcrumbs) { req.setAttribute(Constants.REQ_ATTR_BREADCRUMBS, breadcrumbs); } /** * @param req the servlet request object * @param location the location where to redirect * @see Constants#REQ_ATTR_REDIRECT_LOCATION */ protected void setRedirectLocation(HttpServletRequest req, String location) { if (location.startsWith("./")) { location = location.replaceFirst("\\./", Functions.baseHref(req)); } req.setAttribute(Constants.REQ_ATTR_REDIRECT_LOCATION, location); } /** * Specifies the name of an additional stylesheet used by the module. * <p> * Setting an additional stylesheet is optional, but quite common for HTML * output. * <p> * It is sufficient to specify the name without any extension. The extension * is added automatically if not specified. * * @param req the servlet request object * @param stylesheet the name of the stylesheet */ public void setStylesheet(HttpServletRequest req, String stylesheet) { req.setAttribute(Constants.REQ_ATTR_STYLESHEET, Functions.enforceExt(stylesheet, ".css")); } /** * Sets the view model object. * The type must match the expected type in the JSP file. * * @param req the servlet request object * @param viewModel the view model object */ public void setViewModel(HttpServletRequest req, Object viewModel) { req.setAttribute(Constants.REQ_ATTR_VIEWMODEL, viewModel); } /** * Obtains a request parameter of the specified type. * The specified type must have a single-argument constructor accepting a string to perform conversion. * The constructor of the specified type may throw an exception on conversion failures. * * @param req the servlet request object * @param clazz the class object of the expected type * @param name the name of the parameter * @param <T> the expected type * @return the parameter value or an empty optional, if no parameter with the specified name was found */ protected <T> Optional<T> getParameter(HttpServletRequest req, Class<T> clazz, String name) { if (clazz.isArray()) { final String[] paramValues = req.getParameterValues(name); int len = paramValues == null ? 0 : paramValues.length; final var array = (T) Array.newInstance(clazz.getComponentType(), len); for (int i = 0; i < len; i++) { try { final Constructor<?> ctor = clazz.getComponentType().getConstructor(String.class); Array.set(array, i, ctor.newInstance(paramValues[i])); } catch (ReflectiveOperationException e) { throw new RuntimeException(e); } } return Optional.of(array); } else { final String paramValue = req.getParameter(name); if (paramValue == null) return Optional.empty(); if (clazz.equals(Boolean.class)) { if (paramValue.toLowerCase().equals("false") || paramValue.equals("0")) { return Optional.of((T) Boolean.FALSE); } else { return Optional.of((T) Boolean.TRUE); } } if (clazz.equals(String.class)) return Optional.of((T) paramValue); if (java.sql.Date.class.isAssignableFrom(clazz)) { try { return Optional.of((T) java.sql.Date.valueOf(paramValue)); } catch (IllegalArgumentException ex) { return Optional.empty(); } } try { final Constructor<T> ctor = clazz.getConstructor(String.class); return Optional.of(ctor.newInstance(paramValue)); } catch (ReflectiveOperationException e) { throw new RuntimeException(e); } } } /** * Tries to look up an entity with a key obtained from a request parameter. * * @param req the servlet request object * @param clazz the class representing the type of the request parameter * @param name the name of the request parameter * @param find the find function (typically a DAO function) * @param <T> the type of the request parameter * @param <R> the type of the looked up entity * @return the retrieved entity or an empty optional if there is no such entity or the request parameter was missing * @throws SQLException if the find function throws an exception */ protected <T, R> Optional<R> findByParameter(HttpServletRequest req, Class<T> clazz, String name, SQLFindFunction<? super T, ? extends R> find) throws SQLException { final var param = getParameter(req, clazz, name); if (param.isPresent()) { return Optional.ofNullable(find.apply(param.get())); } else { return Optional.empty(); } } private void forwardToFullView(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException { final String lightpitBundle = "localization.lightpit"; final var mainMenu = List.of( new MenuEntry(new ResourceKey(lightpitBundle, "menu.projects"), "projects/"), new MenuEntry(new ResourceKey(lightpitBundle, "menu.users"), "teams/"), new MenuEntry(new ResourceKey(lightpitBundle, "menu.languages"), "language/") ); for (var entry : mainMenu) { if (Functions.fullPath(req).startsWith("/" + entry.getPathName())) { entry.setActive(true); } } req.setAttribute(Constants.REQ_ATTR_MENU, mainMenu); req.getRequestDispatcher(SITE_JSP).forward(req, resp); } private String sanitizeRequestPath(HttpServletRequest req) { return Optional.ofNullable(req.getPathInfo()).orElse("/"); } private Optional<Method> findMapping(HttpMethod method, HttpServletRequest req) { return Optional.ofNullable(mappings.get(method)).map(rm -> rm.get(sanitizeRequestPath(req))); } private void forwardAsSpecified(ResponseType type, HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { switch (type) { case NONE: return; case HTML: forwardToFullView(req, resp); return; // TODO: implement remaining response types default: throw new AssertionError("ResponseType switch is not exhaustive - this is a bug!"); } } private void doProcess(HttpMethod method, HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { // choose the requested language as session language (if available) or fall back to english, otherwise HttpSession session = req.getSession(); if (session.getAttribute(Constants.SESSION_ATTR_LANGUAGE) == null) { Optional<List<String>> availableLanguages = Functions.availableLanguages(getServletContext()).map(Arrays::asList); Optional<Locale> reqLocale = Optional.of(req.getLocale()); Locale sessionLocale = reqLocale.filter((rl) -> availableLanguages.map((al) -> al.contains(rl.getLanguage())).orElse(false)).orElse(Locale.ENGLISH); session.setAttribute(Constants.SESSION_ATTR_LANGUAGE, sessionLocale); LOG.debug("Setting language for new session {}: {}", session.getId(), sessionLocale.getDisplayLanguage()); } else { Locale sessionLocale = (Locale) session.getAttribute(Constants.SESSION_ATTR_LANGUAGE); resp.setLocale(sessionLocale); LOG.trace("Continuing session {} with language {}", session.getId(), sessionLocale); } // set some internal request attributes final String fullPath = Functions.fullPath(req); req.setAttribute(Constants.REQ_ATTR_BASE_HREF, Functions.baseHref(req)); req.setAttribute(Constants.REQ_ATTR_PATH, fullPath); req.setAttribute(Constants.REQ_ATTR_RESOURCE_BUNDLE, getResourceBundleName()); // if this is an error path, bypass the normal flow if (fullPath.startsWith("/error/")) { final var mapping = findMapping(method, req); if (mapping.isPresent()) { forwardAsSpecified(invokeMapping(mapping.get(), req, resp, null), req, resp); } return; } // obtain a connection and create the data access objects final var db = (DatabaseFacade) req.getServletContext().getAttribute(DatabaseFacade.SC_ATTR_NAME); final var ds = db.getDataSource(); if (ds == null) { resp.sendError(HttpServletResponse.SC_SERVICE_UNAVAILABLE, "JNDI DataSource lookup failed. See log for details."); return; } try (final var connection = ds.getConnection()) { final var dao = createDataAccessObjects(connection); try { connection.setAutoCommit(false); // call the handler, if available, or send an HTTP 404 error final var mapping = findMapping(method, req); if (mapping.isPresent()) { forwardAsSpecified(invokeMapping(mapping.get(), req, resp, dao), req, resp); } else { resp.sendError(HttpServletResponse.SC_NOT_FOUND); } connection.commit(); } catch (SQLException ex) { LOG.warn("Database transaction failed (Code {}): {}", ex.getErrorCode(), ex.getMessage()); LOG.debug("Details: ", ex); resp.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, "Unhandled Transaction Error - Code: " + ex.getErrorCode()); connection.rollback(); } } catch (SQLException ex) { LOG.error("Severe Database Exception (Code {}): {}", ex.getErrorCode(), ex.getMessage()); LOG.debug("Details: ", ex); resp.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, "Database Error - Code: " + ex.getErrorCode()); } } @Override protected final void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { doProcess(HttpMethod.GET, req, resp); } @Override protected final void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { doProcess(HttpMethod.POST, req, resp); } }