LightPIT: comparison src/main/java/de/uapcore/lightpit/AbstractLightPITServlet.java

-:833e0385572a
+:51aa5e267c7f
 import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
 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 {@link LightPITModule}s.
 */
 /**
 * The EL proxy is necessary, because the EL resolver cannot handle annotation properties.
 */
 private LightPITModule.ELProxy moduleInfo = null;
+@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
 *
 * @param req          the servlet request object
 * @param fragmentName the name of the fragment
 * @see Constants#DYN_FRAGMENT_PATH_PREFIX
 */
-public void setDynamicFragment(HttpServletRequest req, String fragmentName) {
+protected void setDynamicFragment(HttpServletRequest req, String fragmentName) {
 req.setAttribute(Constants.REQ_ATTR_FRAGMENT, Functions.dynFragmentPath(fragmentName));
 }
 /**
 * @param req      the servlet request object
 * @param location the location where to redirect
 * @see Constants#REQ_ATTR_REDIRECT_LOCATION
 */
-public void setRedirectLocation(HttpServletRequest req, String 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);
 }
 * @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
 */
-public<T> Optional<T> getParameter(HttpServletRequest req, Class<T> clazz, String name) {
+protected<T> Optional<T> getParameter(HttpServletRequest req, Class<T> clazz, String name) {
 final String paramValue = req.getParameter(name);
 if (paramValue == null) return Optional.empty();
 if (clazz.equals(String.class)) return Optional.of((T)paramValue);
 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 {

Mercurial > hg > LightPIT / file comparison

comparison: src/main/java/de/uapcore/lightpit/AbstractLightPITServlet.java

src/main/java/de/uapcore/lightpit/AbstractLightPITServlet.java