Simplify before filter

Author: jknack

jooby/src/main/java/io/jooby/Route.java

@@ -86,21 +86,40 @@ public interface Decorator {
    * @author edgar
    * @since 2.0.0
    */
-  public interface Before extends Decorator {
-    @Nonnull @Override default Handler apply(@Nonnull Handler next) {
+  public interface Before {
+    /**
+     * Execute application code before next handler.
+     *
+     * @param ctx Web context.
+     * @throws Exception If something goes wrong.
+     */
+    void apply(@Nonnull Context ctx) throws Exception;
+
+    /**
+     * Chain this filter with next one and produces a new before filter.
+     *
+     * @param next Next decorator.
+     * @return A new decorator.
+     */
+    @Nonnull default Before then(@Nonnull Before next) {
       return ctx -> {
-        before(ctx);
-        return next.apply(ctx);
+        apply(ctx);
+        next.apply(ctx);
       };
     }
 
     /**
-     * Execute application code before next handler.
+     * Chain this decorator with a handler and produces a new handler.
      *
-     * @param ctx Web context.
-     * @throws Exception If something goes wrong.
+     * @param next Next handler.
+     * @return A new handler.
      */
-    void before(@Nonnull Context ctx) throws Exception;
+    @Nonnull default Handler then(@Nonnull Handler next) {
+      return ctx -> {
+        apply(ctx);
+        return next.apply(ctx);
+      };
+    }
   }
 
   /**
@@ -205,7 +224,7 @@ public interface Handler extends Serializable {
 
   private List<String> pathKeys;
 
-  private Decorator before;
+  private Before before;
 
   private Handler handler;
 
@@ -241,7 +260,7 @@ public Route(@Nonnull String method,
       @Nonnull List<String> pathKeys,
       @Nonnull Type returnType,
       @Nonnull Handler handler,
-      @Nullable Decorator before,
+      @Nullable Before before,
       @Nullable After after,
       @Nonnull Renderer renderer,
       @Nonnull Map<String, Parser> parsers) {
@@ -281,7 +300,7 @@ public Route(@Nonnull String method,
       @Nonnull String pattern,
       @Nonnull Type returnType,
       @Nonnull Handler handler,
-      @Nullable Decorator before,
+      @Nullable Before before,
       @Nullable After after,
       @Nonnull Renderer renderer,
       @Nonnull Map<String, Parser> parsers) {
@@ -350,7 +369,7 @@ public Route(@Nonnull String method,
    *
    * @return Before pipeline or <code>null</code>.
    */
-  public @Nullable Decorator getBefore() {
+  public @Nullable Before getBefore() {
     return before;
   }
 

jooby/src/main/java/io/jooby/internal/RouterImpl.java

@@ -63,6 +63,7 @@ private static class Stack {
     private String pattern;
     private Executor executor;
     private List<Route.Decorator> filters = new ArrayList<>();
+    private List<Route.Before> beforeList = new ArrayList<>();
     private List<Route.After> afters = new ArrayList<>();
 
     public Stack(String pattern) {
@@ -77,6 +78,10 @@ public void then(Route.After after) {
       afters.add(after);
     }
 
+    public void then(Route.Before before) {
+      beforeList.add(before);
+    }
+
     public Stream<Route.Decorator> toFilter() {
       return filters.stream();
     }
@@ -85,9 +90,14 @@ public Stream<Route.After> toAfter() {
       return afters.stream();
     }
 
+    public Stream<Route.Before> toBefore() {
+      return beforeList.stream();
+    }
+
     public void clear() {
       this.filters.clear();
       this.afters.clear();
+      this.beforeList.clear();
       executor = null;
     }
 
@@ -295,7 +305,8 @@ public Router renderer(@Nonnull MediaType contentType, @Nonnull Renderer rendere
   }
 
   @Nonnull @Override public Router before(@Nonnull Route.Before before) {
-    return decorator(before);
+    stack.peekLast().then(before);
+    return this;
   }
 
   @Nonnull @Override public Router error(@Nonnull ErrorHandler handler) {
@@ -351,10 +362,9 @@ private Route defineRoute(@Nonnull String method, @Nonnull String pattern,
         .collect(Collectors.toList());
 
     /** Before: */
-    Route.Decorator before = null;
-    for (Route.Decorator filter : filters) {
-      before = before == null ? filter : before.then(filter);
-    }
+    Route.Before before = stack.stream()
+        .flatMap(Stack::toBefore)
+        .reduce(null, (it, next) -> it == null ? next : it.then(next));
 
     /** Pipeline: */
     //    Route.Handler pipeline = before == null ? handler : before.then(handler);
@@ -405,7 +415,7 @@ private Route defineRoute(@Nonnull String method, @Nonnull String pattern,
         route.setReturnType(analyzer.returnType(route.getHandle()));
       }
       /** Pipeline: */
-      Route.Decorator before = route.getBefore();
+      Route.Before before = route.getBefore();
       if (route.getProduces().size() > 0) {
         before = before == null ? ACCEPT : ACCEPT.then(before);
       }