universe@7: /*
universe@7: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
universe@34: *
universe@24: * Copyright 2018 Mike Becker. All rights reserved.
universe@34: *
universe@7: * Redistribution and use in source and binary forms, with or without
universe@7: * modification, are permitted provided that the following conditions are met:
universe@7: *
universe@7: * 1. Redistributions of source code must retain the above copyright
universe@7: * notice, this list of conditions and the following disclaimer.
universe@7: *
universe@7: * 2. Redistributions in binary form must reproduce the above copyright
universe@7: * notice, this list of conditions and the following disclaimer in the
universe@7: * documentation and/or other materials provided with the distribution.
universe@7: *
universe@7: * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
universe@7: * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
universe@7: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
universe@7: * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
universe@7: * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
universe@7: * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
universe@7: * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
universe@7: * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
universe@7: * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
universe@7: * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
universe@7: * POSSIBILITY OF SUCH DAMAGE.
universe@34: *
universe@7: */
universe@7: package de.uapcore.lightpit;
universe@7:
universe@167: import de.uapcore.lightpit.dao.DataAccessObject;
universe@167: import de.uapcore.lightpit.dao.PostgresDataAccessObject;
universe@33: import org.slf4j.Logger;
universe@33: import org.slf4j.LoggerFactory;
universe@33:
universe@7: import javax.servlet.ServletException;
universe@7: import javax.servlet.http.HttpServlet;
universe@7: import javax.servlet.http.HttpServletRequest;
universe@7: import javax.servlet.http.HttpServletResponse;
universe@13: import javax.servlet.http.HttpSession;
universe@33: import java.io.IOException;
universe@83: import java.lang.reflect.*;
universe@38: import java.sql.Connection;
universe@38: import java.sql.SQLException;
universe@33: import java.util.*;
universe@63: import java.util.function.Function;
universe@163: import java.util.stream.Collectors;
universe@7:
universe@7: /**
universe@7: * A special implementation of a HTTPServlet which is focused on implementing
universe@79: * the necessary functionality for LightPIT pages.
universe@7: */
universe@9: public abstract class AbstractLightPITServlet extends HttpServlet {
universe@34:
universe@10: private static final Logger LOG = LoggerFactory.getLogger(AbstractLightPITServlet.class);
universe@34:
universe@158: private static final String SITE_JSP = jspPath("site");
universe@33:
universe@10: /**
universe@11: * Invocation mapping gathered from the {@link RequestMapping} annotations.
universe@34: *
universe@18: * Paths in this map must always start with a leading slash, although
universe@18: * the specification in the annotation must not start with a leading slash.
universe@34: *
universe@34: * The reason for this is the different handling of empty paths in
universe@18: * {@link HttpServletRequest#getPathInfo()}.
universe@11: */
universe@130: private final Map> mappings = new HashMap<>();
universe@11:
universe@11: /**
universe@78: * Returns the name of the resource bundle associated with this servlet.
universe@86: *
universe@78: * @return the resource bundle base name
universe@78: */
universe@78: protected abstract String getResourceBundleName();
universe@78:
universe@38:
universe@34: /**
universe@38: * Creates a set of data access objects for the specified connection.
universe@33: *
universe@38: * @param connection the SQL connection
universe@38: * @return a set of data access objects
universe@17: */
universe@167: private DataAccessObject createDataAccessObjects(Connection connection) {
universe@151: final var df = (DataSourceProvider) getServletContext().getAttribute(DataSourceProvider.Companion.getSC_ATTR_NAME());
universe@158: if (df.getDialect() == DataSourceProvider.Dialect.Postgres) {
universe@167: return new PostgresDataAccessObject(connection);
universe@38: }
universe@151: throw new UnsupportedOperationException("Non-exhaustive if-else - this is a bug.");
universe@17: }
universe@33:
universe@167: private void invokeMapping(Map.Entry mapping, HttpServletRequest req, HttpServletResponse resp, DataAccessObject dao) throws IOException {
universe@130: final var pathPattern = mapping.getKey();
universe@130: final var method = mapping.getValue();
universe@11: try {
universe@14: LOG.trace("invoke {}#{}", method.getDeclaringClass().getName(), method.getName());
universe@42: final var paramTypes = method.getParameterTypes();
universe@42: final var paramValues = new Object[paramTypes.length];
universe@42: for (int i = 0; i < paramTypes.length; i++) {
universe@42: if (paramTypes[i].isAssignableFrom(HttpServletRequest.class)) {
universe@42: paramValues[i] = req;
universe@42: } else if (paramTypes[i].isAssignableFrom(HttpServletResponse.class)) {
universe@42: paramValues[i] = resp;
universe@42: }
universe@167: if (paramTypes[i].isAssignableFrom(DataAccessObject.class)) {
universe@42: paramValues[i] = dao;
universe@42: }
universe@130: if (paramTypes[i].isAssignableFrom(PathParameters.class)) {
universe@130: paramValues[i] = pathPattern.obtainPathParameters(sanitizeRequestPath(req));
universe@130: }
universe@42: }
universe@157: method.invoke(this, paramValues);
universe@73: } catch (InvocationTargetException ex) {
universe@73: LOG.error("invocation of method {}::{} failed: {}",
universe@73: method.getDeclaringClass().getName(), method.getName(), ex.getTargetException().getMessage());
universe@73: LOG.debug("Details: ", ex.getTargetException());
universe@73: resp.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, ex.getTargetException().getMessage());
universe@12: } catch (ReflectiveOperationException | ClassCastException ex) {
universe@73: LOG.error("invocation of method {}::{} failed: {}",
universe@73: method.getDeclaringClass().getName(), method.getName(), ex.getMessage());
universe@38: LOG.debug("Details: ", ex);
universe@73: resp.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, ex.getMessage());
universe@11: }
universe@11: }
universe@11:
universe@11: @Override
universe@11: public void init() throws ServletException {
universe@78: scanForRequestMappings();
universe@33:
universe@12: LOG.trace("{} initialized", getServletName());
universe@12: }
universe@12:
universe@12: private void scanForRequestMappings() {
universe@12: try {
universe@11: Method[] methods = getClass().getDeclaredMethods();
universe@11: for (Method method : methods) {
universe@11: Optional mapping = Optional.ofNullable(method.getAnnotation(RequestMapping.class));
universe@11: if (mapping.isPresent()) {
universe@130: if (mapping.get().requestPath().isBlank()) {
universe@130: LOG.warn("{} is annotated with {} but request path is empty",
universe@130: method.getName(), RequestMapping.class.getSimpleName()
universe@130: );
universe@130: continue;
universe@130: }
universe@130:
universe@11: if (!Modifier.isPublic(method.getModifiers())) {
universe@11: LOG.warn("{} is annotated with {} but is not public",
universe@11: method.getName(), RequestMapping.class.getSimpleName()
universe@11: );
universe@11: continue;
universe@11: }
universe@11: if (Modifier.isAbstract(method.getModifiers())) {
universe@11: LOG.warn("{} is annotated with {} but is abstract",
universe@11: method.getName(), RequestMapping.class.getSimpleName()
universe@11: );
universe@11: continue;
universe@11: }
universe@12:
universe@42: boolean paramsInjectible = true;
universe@42: for (var param : method.getParameterTypes()) {
universe@42: paramsInjectible &= HttpServletRequest.class.isAssignableFrom(param)
universe@167: || HttpServletResponse.class.isAssignableFrom(param)
universe@167: || PathParameters.class.isAssignableFrom(param)
universe@167: || DataAccessObject.class.isAssignableFrom(param);
universe@42: }
universe@42: if (paramsInjectible) {
universe@130: try {
universe@130: PathPattern pathPattern = new PathPattern(mapping.get().requestPath());
universe@12:
universe@131: final var methodMappings = mappings.computeIfAbsent(mapping.get().method(), k -> new HashMap<>());
universe@131: final var currentMapping = methodMappings.putIfAbsent(pathPattern, method);
universe@131: if (currentMapping != null) {
universe@131: LOG.warn("Cannot map {} {} to {} in class {} - this would override the mapping to {}",
universe@130: mapping.get().method(),
universe@131: mapping.get().requestPath(),
universe@131: method.getName(),
universe@131: getClass().getSimpleName(),
universe@131: currentMapping.getName()
universe@130: );
universe@130: }
universe@130:
universe@130: LOG.debug("{} {} maps to {}::{}",
universe@11: mapping.get().method(),
universe@130: mapping.get().requestPath(),
universe@130: getClass().getSimpleName(),
universe@130: method.getName()
universe@130: );
universe@130: } catch (IllegalArgumentException ex) {
universe@130: LOG.warn("Request mapping for {} failed: path pattern '{}' is syntactically invalid",
universe@130: method.getName(), mapping.get().requestPath()
universe@11: );
universe@11: }
universe@11: } else {
universe@130: LOG.warn("{} is annotated with {} but has the wrong parameters - only HttpServletRequest, HttpServletResponse, PathParameters, and DataAccessObjects are allowed",
universe@11: method.getName(), RequestMapping.class.getSimpleName()
universe@11: );
universe@11: }
universe@11: }
universe@11: }
universe@12: } catch (SecurityException ex) {
universe@12: LOG.error("Scan for request mappings on declared methods failed.", ex);
universe@11: }
universe@11: }
universe@11:
universe@11: @Override
universe@11: public void destroy() {
universe@11: mappings.clear();
universe@11: LOG.trace("{} destroyed", getServletName());
universe@11: }
universe@34:
universe@11: /**
universe@74: * Sets the name of the content page.
universe@34: *
universe@13: * It is sufficient to specify the name without any extension. The extension
universe@13: * is added automatically if not specified.
universe@34: *
universe@74: * @param req the servlet request object
universe@74: * @param pageName the name of the content page
universe@74: * @see Constants#REQ_ATTR_CONTENT_PAGE
universe@11: */
universe@74: protected void setContentPage(HttpServletRequest req, String pageName) {
universe@158: req.setAttribute(Constants.REQ_ATTR_CONTENT_PAGE, jspPath(pageName));
universe@13: }
universe@34:
universe@13: /**
universe@96: * Sets the navigation menu.
universe@71: *
universe@109: * @param req the servlet request object
universe@109: * @param jspName the name of the menu's jsp file
universe@96: * @see Constants#REQ_ATTR_NAVIGATION
universe@71: */
universe@109: protected void setNavigationMenu(HttpServletRequest req, String jspName) {
universe@158: req.setAttribute(Constants.REQ_ATTR_NAVIGATION, jspPath(jspName));
universe@71: }
universe@71:
universe@71: /**
universe@47: * @param req the servlet request object
universe@47: * @param location the location where to redirect
universe@47: * @see Constants#REQ_ATTR_REDIRECT_LOCATION
universe@47: */
universe@63: protected void setRedirectLocation(HttpServletRequest req, String location) {
universe@47: if (location.startsWith("./")) {
universe@158: location = location.replaceFirst("\\./", baseHref(req));
universe@47: }
universe@47: req.setAttribute(Constants.REQ_ATTR_REDIRECT_LOCATION, location);
universe@47: }
universe@47:
universe@47: /**
universe@163: * Specifies the names of additional stylesheets used by this Servlet.
universe@34: *
universe@13: * It is sufficient to specify the name without any extension. The extension
universe@13: * is added automatically if not specified.
universe@34: *
universe@163: * @param req the servlet request object
universe@163: * @param stylesheets the names of the stylesheets
universe@13: */
universe@163: public void setStylesheet(HttpServletRequest req, String ... stylesheets) {
universe@163: req.setAttribute(Constants.REQ_ATTR_STYLESHEET, Arrays
universe@163: .stream(stylesheets)
universe@163: .map(s -> enforceExt(s, ".css"))
universe@163: .collect(Collectors.toUnmodifiableList()));
universe@10: }
universe@34:
universe@47: /**
universe@86: * Sets the view model object.
universe@86: * The type must match the expected type in the JSP file.
universe@86: *
universe@86: * @param req the servlet request object
universe@86: * @param viewModel the view model object
universe@86: */
universe@86: public void setViewModel(HttpServletRequest req, Object viewModel) {
universe@86: req.setAttribute(Constants.REQ_ATTR_VIEWMODEL, viewModel);
universe@86: }
universe@86:
universe@131: private Optional parseParameter(String paramValue, Class clazz) {
universe@131: if (paramValue == null) return Optional.empty();
universe@131: if (clazz.equals(Boolean.class)) {
universe@168: if (paramValue.equalsIgnoreCase("false") || paramValue.equals("0")) {
universe@131: return Optional.of((T) Boolean.FALSE);
universe@131: } else {
universe@131: return Optional.of((T) Boolean.TRUE);
universe@131: }
universe@131: }
universe@131: if (clazz.equals(String.class)) return Optional.of((T) paramValue);
universe@131: if (java.sql.Date.class.isAssignableFrom(clazz)) {
universe@131: try {
universe@131: return Optional.of((T) java.sql.Date.valueOf(paramValue));
universe@131: } catch (IllegalArgumentException ex) {
universe@131: return Optional.empty();
universe@131: }
universe@131: }
universe@131: try {
universe@131: final Constructor ctor = clazz.getConstructor(String.class);
universe@131: return Optional.of(ctor.newInstance(paramValue));
universe@131: } catch (ReflectiveOperationException e) {
universe@131: // does not type check and is not convertible - treat as if the parameter was never set
universe@131: return Optional.empty();
universe@131: }
universe@131: }
universe@131:
universe@86: /**
universe@47: * Obtains a request parameter of the specified type.
universe@47: * The specified type must have a single-argument constructor accepting a string to perform conversion.
universe@47: * The constructor of the specified type may throw an exception on conversion failures.
universe@47: *
universe@71: * @param req the servlet request object
universe@47: * @param clazz the class object of the expected type
universe@71: * @param name the name of the parameter
universe@71: * @param the expected type
universe@47: * @return the parameter value or an empty optional, if no parameter with the specified name was found
universe@47: */
universe@71: protected Optional getParameter(HttpServletRequest req, Class clazz, String name) {
universe@83: if (clazz.isArray()) {
universe@83: final String[] paramValues = req.getParameterValues(name);
universe@83: int len = paramValues == null ? 0 : paramValues.length;
universe@83: final var array = (T) Array.newInstance(clazz.getComponentType(), len);
universe@86: for (int i = 0; i < len; i++) {
universe@83: try {
universe@83: final Constructor> ctor = clazz.getComponentType().getConstructor(String.class);
universe@83: Array.set(array, i, ctor.newInstance(paramValues[i]));
universe@83: } catch (ReflectiveOperationException e) {
universe@83: throw new RuntimeException(e);
universe@83: }
universe@83: }
universe@83: return Optional.of(array);
universe@83: } else {
universe@131: return parseParameter(req.getParameter(name), clazz);
universe@80: }
universe@47: }
universe@47:
universe@63: /**
universe@63: * Tries to look up an entity with a key obtained from a request parameter.
universe@63: *
universe@71: * @param req the servlet request object
universe@63: * @param clazz the class representing the type of the request parameter
universe@71: * @param name the name of the request parameter
universe@71: * @param find the find function (typically a DAO function)
universe@71: * @param the type of the request parameter
universe@71: * @param the type of the looked up entity
universe@63: * @return the retrieved entity or an empty optional if there is no such entity or the request parameter was missing
universe@63: * @throws SQLException if the find function throws an exception
universe@63: */
universe@167: protected Optional findByParameter(HttpServletRequest req, Class clazz, String name, Function super T, ? extends R> find) {
universe@63: final var param = getParameter(req, clazz, name);
universe@63: if (param.isPresent()) {
universe@63: return Optional.ofNullable(find.apply(param.get()));
universe@63: } else {
universe@63: return Optional.empty();
universe@63: }
universe@63: }
universe@63:
universe@168: protected void setAttributeFromParameter(HttpServletRequest req, String name) {
universe@168: final var parm = req.getParameter(name);
universe@168: if (parm != null) {
universe@168: req.setAttribute(name, parm);
universe@168: }
universe@168: }
universe@168:
universe@45: private String sanitizeRequestPath(HttpServletRequest req) {
universe@45: return Optional.ofNullable(req.getPathInfo()).orElse("/");
universe@45: }
universe@45:
universe@130: private Optional> findMapping(HttpMethod method, HttpServletRequest req) {
universe@130: return Optional.ofNullable(mappings.get(method)).flatMap(rm ->
universe@130: rm.entrySet().stream().filter(
universe@130: kv -> kv.getKey().matches(sanitizeRequestPath(req))
universe@130: ).findAny()
universe@130: );
universe@11: }
universe@34:
universe@157: protected void renderSite(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
universe@157: req.getRequestDispatcher(SITE_JSP).forward(req, resp);
universe@12: }
universe@34:
universe@158: protected Optional availableLanguages() {
universe@158: return Optional.ofNullable(getServletContext().getInitParameter(Constants.CTX_ATTR_LANGUAGES)).map((x) -> x.split("\\s*,\\s*"));
universe@158: }
universe@158:
universe@158: private static String baseHref(HttpServletRequest req) {
universe@158: return String.format("%s://%s:%d%s/",
universe@158: req.getScheme(),
universe@158: req.getServerName(),
universe@158: req.getServerPort(),
universe@158: req.getContextPath());
universe@158: }
universe@158:
universe@158: private static String enforceExt(String filename, String ext) {
universe@158: return filename.endsWith(ext) ? filename : filename + ext;
universe@158: }
universe@158:
universe@158: private static String jspPath(String filename) {
universe@158: return enforceExt(Constants.JSP_PATH_PREFIX + filename, ".jsp");
universe@158: }
universe@158:
universe@38: private void doProcess(HttpMethod method, HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
universe@160: // the very first thing to do is to force UTF-8
universe@160: req.setCharacterEncoding("UTF-8");
universe@27:
universe@13: // choose the requested language as session language (if available) or fall back to english, otherwise
universe@20: HttpSession session = req.getSession();
universe@13: if (session.getAttribute(Constants.SESSION_ATTR_LANGUAGE) == null) {
universe@158: Optional> availableLanguages = availableLanguages().map(Arrays::asList);
universe@13: Optional reqLocale = Optional.of(req.getLocale());
universe@13: Locale sessionLocale = reqLocale.filter((rl) -> availableLanguages.map((al) -> al.contains(rl.getLanguage())).orElse(false)).orElse(Locale.ENGLISH);
universe@13: session.setAttribute(Constants.SESSION_ATTR_LANGUAGE, sessionLocale);
universe@34: LOG.debug("Setting language for new session {}: {}", session.getId(), sessionLocale.getDisplayLanguage());
universe@14: } else {
universe@15: Locale sessionLocale = (Locale) session.getAttribute(Constants.SESSION_ATTR_LANGUAGE);
universe@15: resp.setLocale(sessionLocale);
universe@15: LOG.trace("Continuing session {} with language {}", session.getId(), sessionLocale);
universe@13: }
universe@34:
universe@21: // set some internal request attributes
universe@158: final String fullPath = req.getServletPath() + Optional.ofNullable(req.getPathInfo()).orElse("");
universe@158: req.setAttribute(Constants.REQ_ATTR_BASE_HREF, baseHref(req));
universe@53: req.setAttribute(Constants.REQ_ATTR_PATH, fullPath);
universe@78: req.setAttribute(Constants.REQ_ATTR_RESOURCE_BUNDLE, getResourceBundleName());
universe@34:
universe@53: // if this is an error path, bypass the normal flow
universe@53: if (fullPath.startsWith("/error/")) {
universe@53: final var mapping = findMapping(method, req);
universe@53: if (mapping.isPresent()) {
universe@157: invokeMapping(mapping.get(), req, resp, null);
universe@53: }
universe@53: return;
universe@53: }
universe@53:
universe@38: // obtain a connection and create the data access objects
universe@151: final var db = (DataSourceProvider) req.getServletContext().getAttribute(DataSourceProvider.Companion.getSC_ATTR_NAME());
universe@53: final var ds = db.getDataSource();
universe@53: if (ds == null) {
universe@53: resp.sendError(HttpServletResponse.SC_SERVICE_UNAVAILABLE, "JNDI DataSource lookup failed. See log for details.");
universe@53: return;
universe@53: }
universe@53: try (final var connection = ds.getConnection()) {
universe@38: final var dao = createDataAccessObjects(connection);
universe@39: try {
universe@39: connection.setAutoCommit(false);
universe@39: // call the handler, if available, or send an HTTP 404 error
universe@39: final var mapping = findMapping(method, req);
universe@39: if (mapping.isPresent()) {
universe@157: invokeMapping(mapping.get(), req, resp, dao);
universe@39: } else {
universe@39: resp.sendError(HttpServletResponse.SC_NOT_FOUND);
universe@39: }
universe@39: connection.commit();
universe@39: } catch (SQLException ex) {
universe@39: LOG.warn("Database transaction failed (Code {}): {}", ex.getErrorCode(), ex.getMessage());
universe@39: LOG.debug("Details: ", ex);
universe@54: resp.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, "Unhandled Transaction Error - Code: " + ex.getErrorCode());
universe@39: connection.rollback();
universe@38: }
universe@38: } catch (SQLException ex) {
universe@39: LOG.error("Severe Database Exception (Code {}): {}", ex.getErrorCode(), ex.getMessage());
universe@38: LOG.debug("Details: ", ex);
universe@54: resp.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, "Database Error - Code: " + ex.getErrorCode());
universe@12: }
universe@12: }
universe@34:
universe@7: @Override
universe@7: protected final void doGet(HttpServletRequest req, HttpServletResponse resp)
universe@7: throws ServletException, IOException {
universe@12: doProcess(HttpMethod.GET, req, resp);
universe@7: }
universe@7:
universe@7: @Override
universe@7: protected final void doPost(HttpServletRequest req, HttpServletResponse resp)
universe@7: throws ServletException, IOException {
universe@12: doProcess(HttpMethod.POST, req, resp);
universe@7: }
universe@7: }