--- a/src/java/de/uapcore/lightpit/AbstractLightPITServlet.java Sat Dec 16 20:19:28 2017 +0100
+++ b/src/java/de/uapcore/lightpit/AbstractLightPITServlet.java Sun Dec 17 01:45:28 2017 +0100
@@ -29,6 +29,12 @@
package de.uapcore.lightpit;
import java.io.IOException;
+import java.lang.reflect.Method;
+import java.lang.reflect.Modifier;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Optional;
+import java.util.function.BiConsumer;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
@@ -43,9 +49,23 @@
public abstract class AbstractLightPITServlet extends HttpServlet {
private static final Logger LOG = LoggerFactory.getLogger(AbstractLightPITServlet.class);
+
+ /**
+ * Store a reference to the annotation for quicker access.
+ */
+ private Optional<LightPITModule> moduleInfo = Optional.empty();
+ /**
+ * The EL proxy is necessary, because the EL resolver cannot handle annotation properties.
+ */
+ private Optional<LightPITModule.ELProxy> moduleInfoELProxy = Optional.empty();
/**
+ * Invocation mapping gathered from the {@link RequestMapping} annotations.
+ */
+ private final Map<HttpMethod, Map<String, BiConsumer<HttpServletRequest, HttpServletResponse>>> mappings = new HashMap<>();
+
+ /**
* Gives implementing modules access to the {@link ModuleManager}.
* @return the module manager
*/
@@ -53,25 +73,114 @@
return (ModuleManager) getServletContext().getAttribute(ModuleManager.SC_ATTR_NAME);
}
- private void addPathInformation(HttpServletRequest req) {
- final String path = req.getServletPath()+"/"+req.getPathInfo();
- req.setAttribute(Constants.REQ_ATTR_PATH, path);
+ private void invokeMapping(Method method, HttpServletRequest req, HttpServletResponse resp) {
+ try {
+ LOG.debug("invoke {}", method.getName());
+ method.invoke(this, req, resp);
+ } catch (ReflectiveOperationException ex) {
+ LOG.error(String.format("invocation of method %s failed", method.getName()), ex);
+ }
+ }
+
+ @Override
+ public void init() throws ServletException {
+ moduleInfo = Optional.ofNullable(this.getClass().getAnnotation(LightPITModule.class));
+ moduleInfoELProxy = moduleInfo.map(LightPITModule.ELProxy::convert);
+
+ if (moduleInfo.isPresent()) {
+ 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;
+ }
+
+ Class<?>[] params = method.getParameterTypes();
+ if (params.length == 2
+ && HttpServletRequest.class.isAssignableFrom(params[0])
+ && HttpServletResponse.class.isAssignableFrom(params[1])) {
+
+ if (mappings.computeIfAbsent(mapping.get().method(), k -> new HashMap<>()).
+ putIfAbsent(mapping.get().requestPath(),
+ (req, resp) -> invokeMapping(method, req, resp)) != null) {
+ LOG.warn("{} {} has multiple mappings",
+ mapping.get().method(),
+ mapping.get().requestPath()
+ );
+ }
+
+ LOG.info("{} {} maps to {}",
+ mapping.get().method(),
+ mapping.get().requestPath(),
+ method.getName()
+ );
+ } else {
+ LOG.warn("{} is annotated with {} but has the wrong signature - (HttpServletRequest,HttpServletResponse) required",
+ method.getName(), RequestMapping.class.getSimpleName()
+ );
+ }
+ }
+ }
+ }
+
+ LOG.trace("{} initialized", getServletName());
+ }
+
+ @Override
+ public void destroy() {
+ mappings.clear();
+ LOG.trace("{} destroyed", getServletName());
+ }
+
+
+ /**
+ * Sets several requests attributes, that can be used by the JSP.
+ *
+ * @param req the servlet request object
+ * @see Constants#REQ_ATTR_PATH
+ * @see Constants#REQ_ATTR_MODULE_CLASSNAME
+ * @see Constants#REQ_ATTR_MODULE_INFO
+ */
+ private void setGenericRequestAttributes(HttpServletRequest req) {
+ req.setAttribute(Constants.REQ_ATTR_PATH, Functions.fullPath(req));
+
+ req.setAttribute(Constants.REQ_ATTR_MODULE_CLASSNAME, this.getClass().getName());
+
+ moduleInfoELProxy.ifPresent((proxy) -> req.setAttribute(Constants.REQ_ATTR_MODULE_INFO, proxy));
}
private void forwardToFullView(HttpServletRequest req, HttpServletResponse resp)
throws IOException, ServletException {
- addPathInformation(req);
-
- final ModuleManager mm = getModuleManager();
- req.setAttribute(Constants.REQ_ATTR_MENU, mm.getMainMenu());
-
+ setGenericRequestAttributes(req);
+ req.setAttribute(Constants.REQ_ATTR_MENU, getModuleManager().getMainMenu());
req.getRequestDispatcher(Functions.jspPath("full.jsp")).forward(req, resp);
}
+ private Optional<BiConsumer<HttpServletRequest, HttpServletResponse>> findMapping(HttpMethod method, HttpServletRequest req) {
+ return Optional.ofNullable(mappings.get(method)).map(
+ (rm) -> rm.get(Optional.ofNullable(req.getPathInfo()).orElse(""))
+ );
+ }
+
@Override
protected final void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
+
+ findMapping(HttpMethod.GET, req).ifPresent((consumer) -> consumer.accept(req, resp));
+
+ // TODO: let the invoked handler decide (signature must be changed from a BiConsumer to a BiFunction)
+ // TODO: we should call a default handler, if no specific mapping could be found
forwardToFullView(req, resp);
}
@@ -79,6 +188,8 @@
protected final void doPost(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
+ findMapping(HttpMethod.POST, req).ifPresent((consumer) -> consumer.accept(req, resp));
+
forwardToFullView(req, resp);
}
}