1.1 --- a/src/java/de/uapcore/lightpit/AbstractLightPITServlet.java Sat Dec 16 20:19:28 2017 +0100
1.2 +++ b/src/java/de/uapcore/lightpit/AbstractLightPITServlet.java Sun Dec 17 01:45:28 2017 +0100
1.3 @@ -29,6 +29,12 @@
1.4 package de.uapcore.lightpit;
1.5
1.6 import java.io.IOException;
1.7 +import java.lang.reflect.Method;
1.8 +import java.lang.reflect.Modifier;
1.9 +import java.util.HashMap;
1.10 +import java.util.Map;
1.11 +import java.util.Optional;
1.12 +import java.util.function.BiConsumer;
1.13 import javax.servlet.ServletException;
1.14 import javax.servlet.http.HttpServlet;
1.15 import javax.servlet.http.HttpServletRequest;
1.16 @@ -43,9 +49,23 @@
1.17 public abstract class AbstractLightPITServlet extends HttpServlet {
1.18
1.19 private static final Logger LOG = LoggerFactory.getLogger(AbstractLightPITServlet.class);
1.20 +
1.21 + /**
1.22 + * Store a reference to the annotation for quicker access.
1.23 + */
1.24 + private Optional<LightPITModule> moduleInfo = Optional.empty();
1.25
1.26 + /**
1.27 + * The EL proxy is necessary, because the EL resolver cannot handle annotation properties.
1.28 + */
1.29 + private Optional<LightPITModule.ELProxy> moduleInfoELProxy = Optional.empty();
1.30
1.31 /**
1.32 + * Invocation mapping gathered from the {@link RequestMapping} annotations.
1.33 + */
1.34 + private final Map<HttpMethod, Map<String, BiConsumer<HttpServletRequest, HttpServletResponse>>> mappings = new HashMap<>();
1.35 +
1.36 + /**
1.37 * Gives implementing modules access to the {@link ModuleManager}.
1.38 * @return the module manager
1.39 */
1.40 @@ -53,25 +73,114 @@
1.41 return (ModuleManager) getServletContext().getAttribute(ModuleManager.SC_ATTR_NAME);
1.42 }
1.43
1.44 - private void addPathInformation(HttpServletRequest req) {
1.45 - final String path = req.getServletPath()+"/"+req.getPathInfo();
1.46 - req.setAttribute(Constants.REQ_ATTR_PATH, path);
1.47 + private void invokeMapping(Method method, HttpServletRequest req, HttpServletResponse resp) {
1.48 + try {
1.49 + LOG.debug("invoke {}", method.getName());
1.50 + method.invoke(this, req, resp);
1.51 + } catch (ReflectiveOperationException ex) {
1.52 + LOG.error(String.format("invocation of method %s failed", method.getName()), ex);
1.53 + }
1.54 + }
1.55 +
1.56 + @Override
1.57 + public void init() throws ServletException {
1.58 + moduleInfo = Optional.ofNullable(this.getClass().getAnnotation(LightPITModule.class));
1.59 + moduleInfoELProxy = moduleInfo.map(LightPITModule.ELProxy::convert);
1.60 +
1.61 + if (moduleInfo.isPresent()) {
1.62 + Method[] methods = getClass().getDeclaredMethods();
1.63 + for (Method method : methods) {
1.64 + Optional<RequestMapping> mapping = Optional.ofNullable(method.getAnnotation(RequestMapping.class));
1.65 + if (mapping.isPresent()) {
1.66 + if (!Modifier.isPublic(method.getModifiers())) {
1.67 + LOG.warn("{} is annotated with {} but is not public",
1.68 + method.getName(), RequestMapping.class.getSimpleName()
1.69 + );
1.70 + continue;
1.71 + }
1.72 + if (Modifier.isAbstract(method.getModifiers())) {
1.73 + LOG.warn("{} is annotated with {} but is abstract",
1.74 + method.getName(), RequestMapping.class.getSimpleName()
1.75 + );
1.76 + continue;
1.77 + }
1.78 +
1.79 + Class<?>[] params = method.getParameterTypes();
1.80 + if (params.length == 2
1.81 + && HttpServletRequest.class.isAssignableFrom(params[0])
1.82 + && HttpServletResponse.class.isAssignableFrom(params[1])) {
1.83 +
1.84 + if (mappings.computeIfAbsent(mapping.get().method(), k -> new HashMap<>()).
1.85 + putIfAbsent(mapping.get().requestPath(),
1.86 + (req, resp) -> invokeMapping(method, req, resp)) != null) {
1.87 + LOG.warn("{} {} has multiple mappings",
1.88 + mapping.get().method(),
1.89 + mapping.get().requestPath()
1.90 + );
1.91 + }
1.92 +
1.93 + LOG.info("{} {} maps to {}",
1.94 + mapping.get().method(),
1.95 + mapping.get().requestPath(),
1.96 + method.getName()
1.97 + );
1.98 + } else {
1.99 + LOG.warn("{} is annotated with {} but has the wrong signature - (HttpServletRequest,HttpServletResponse) required",
1.100 + method.getName(), RequestMapping.class.getSimpleName()
1.101 + );
1.102 + }
1.103 + }
1.104 + }
1.105 + }
1.106 +
1.107 + LOG.trace("{} initialized", getServletName());
1.108 + }
1.109 +
1.110 + @Override
1.111 + public void destroy() {
1.112 + mappings.clear();
1.113 + LOG.trace("{} destroyed", getServletName());
1.114 + }
1.115 +
1.116 +
1.117 + /**
1.118 + * Sets several requests attributes, that can be used by the JSP.
1.119 + *
1.120 + * @param req the servlet request object
1.121 + * @see Constants#REQ_ATTR_PATH
1.122 + * @see Constants#REQ_ATTR_MODULE_CLASSNAME
1.123 + * @see Constants#REQ_ATTR_MODULE_INFO
1.124 + */
1.125 + private void setGenericRequestAttributes(HttpServletRequest req) {
1.126 + req.setAttribute(Constants.REQ_ATTR_PATH, Functions.fullPath(req));
1.127 +
1.128 + req.setAttribute(Constants.REQ_ATTR_MODULE_CLASSNAME, this.getClass().getName());
1.129 +
1.130 + moduleInfoELProxy.ifPresent((proxy) -> req.setAttribute(Constants.REQ_ATTR_MODULE_INFO, proxy));
1.131 }
1.132
1.133 private void forwardToFullView(HttpServletRequest req, HttpServletResponse resp)
1.134 throws IOException, ServletException {
1.135
1.136 - addPathInformation(req);
1.137 -
1.138 - final ModuleManager mm = getModuleManager();
1.139 - req.setAttribute(Constants.REQ_ATTR_MENU, mm.getMainMenu());
1.140 -
1.141 + setGenericRequestAttributes(req);
1.142 + req.setAttribute(Constants.REQ_ATTR_MENU, getModuleManager().getMainMenu());
1.143 req.getRequestDispatcher(Functions.jspPath("full.jsp")).forward(req, resp);
1.144 }
1.145
1.146 + private Optional<BiConsumer<HttpServletRequest, HttpServletResponse>> findMapping(HttpMethod method, HttpServletRequest req) {
1.147 + return Optional.ofNullable(mappings.get(method)).map(
1.148 + (rm) -> rm.get(Optional.ofNullable(req.getPathInfo()).orElse(""))
1.149 + );
1.150 + }
1.151 +
1.152 @Override
1.153 protected final void doGet(HttpServletRequest req, HttpServletResponse resp)
1.154 throws ServletException, IOException {
1.155 +
1.156 + findMapping(HttpMethod.GET, req).ifPresent((consumer) -> consumer.accept(req, resp));
1.157 +
1.158 + // TODO: let the invoked handler decide (signature must be changed from a BiConsumer to a BiFunction)
1.159 + // TODO: we should call a default handler, if no specific mapping could be found
1.160 forwardToFullView(req, resp);
1.161 }
1.162
1.163 @@ -79,6 +188,8 @@
1.164 protected final void doPost(HttpServletRequest req, HttpServletResponse resp)
1.165 throws ServletException, IOException {
1.166
1.167 + findMapping(HttpMethod.POST, req).ifPresent((consumer) -> consumer.accept(req, resp));
1.168 +
1.169 forwardToFullView(req, resp);
1.170 }
1.171 }
