Align server filter pipeline with main FilterChainImpl and HttpResponseBuilder

Author: viktorlindell12

src/main/java/org/example/filter/FilterChainImpl.java

@@ -1,24 +1,27 @@
 package org.example.filter;
 
-import org.example.http.HttpResponseBuilder;
 import org.example.httpparser.HttpRequest;
-
+import org.example.http.HttpResponseBuilder;
 
 import java.util.List;
-
-/*
-* The default class of FilterChain,
-* Contains a list of filters. For each of the filter, will execute the doFilter method.
-*
- */
+import java.util.function.BiConsumer;
 
 public class FilterChainImpl implements FilterChain {
 
     private final List<Filter> filters;
+    private final BiConsumer<HttpRequest, HttpResponseBuilder> terminalHandler;
     private int index = 0;
 
     public FilterChainImpl(List<Filter> filters) {
+        this(filters, (req, resp) -> {
+            // default no-op (preserves previous behavior)
+        });
+    }
+
+    public FilterChainImpl(List<Filter> filters,
+                           BiConsumer<HttpRequest, HttpResponseBuilder> terminalHandler) {
         this.filters = filters;
+        this.terminalHandler = terminalHandler;
     }
 
     @Override
@@ -27,7 +30,7 @@ public void doFilter(HttpRequest request, HttpResponseBuilder response) {
             Filter next = filters.get(index++);
             next.doFilter(request, response, this);
         } else {
-            // TODO: when no more filters, should execute the request
+            terminalHandler.accept(request, response);
         }
     }
 }

src/main/java/org/example/server/ConfigurableFilterPipeline.java

@@ -1,8 +1,14 @@
 package org.example.server;
 
+import org.example.filter.Filter;
+import org.example.filter.FilterChainImpl;
+import org.example.httpparser.HttpRequest;
+import org.example.http.HttpResponseBuilder;
+
 import java.util.ArrayList;
 import java.util.Comparator;
 import java.util.List;
+import java.util.function.BiConsumer;
 
 public class ConfigurableFilterPipeline {
 
@@ -12,7 +18,8 @@ public ConfigurableFilterPipeline(List<FilterRegistration> registrations) {
         this.registrations = registrations;
     }
 
-    public HttpResponse execute(HttpRequest request, TerminalHandler handler) {
+    public HttpResponseBuilder execute(HttpRequest request,
+                                       BiConsumer<HttpRequest, HttpResponseBuilder> terminalHandler) {
 
         List<FilterRegistration> globalRegs = new ArrayList<>();
         List<FilterRegistration> routeRegs = new ArrayList<>();
@@ -21,7 +28,7 @@ public HttpResponse execute(HttpRequest request, TerminalHandler handler) {
             if (reg.isGlobal()) {
                 globalRegs.add(reg);
             } else {
-                if (matchesAny(reg.routePatterns(), request.path())) {
+                if (matchesAny(reg.routePatterns(), request.getPath())) {
                     routeRegs.add(reg);
                 }
             }
@@ -33,19 +40,21 @@ public HttpResponse execute(HttpRequest request, TerminalHandler handler) {
         globalRegs.sort(byOrder);
         routeRegs.sort(byOrder);
 
-        List<HttpFilter> allFilters = new ArrayList<>(globalRegs.size() + routeRegs.size());
+        List<Filter> allFilters = new ArrayList<>(globalRegs.size() + routeRegs.size());
         for (FilterRegistration reg : globalRegs) {
             allFilters.add(reg.filter());
         }
         for (FilterRegistration reg : routeRegs) {
             allFilters.add(reg.filter());
         }
 
-        return buildChain(allFilters, handler).next(request);
+        HttpResponseBuilder response = new HttpResponseBuilder();
+        new FilterChainImpl(allFilters, terminalHandler).doFilter(request, response);
+        return response;
     }
 
     private boolean matchesAny(List<String> patterns, String path) {
-        if (patterns == null) return false;
+        if (patterns == null || path == null) return false;
 
         for (String pattern : patterns) {
             if (RoutePattern.matches(pattern, path)) {
@@ -55,77 +64,4 @@ private boolean matchesAny(List<String> patterns, String path) {
 
         return false;
     }
-
-    private FilterChain buildChain(List<HttpFilter> filters, TerminalHandler handler) {
-
-        FilterChain chain = new FilterChain() {
-            @Override
-            public HttpResponse next(HttpRequest request) {
-                return handler.handle(request);
-            }
-        };
-
-        for (int i = filters.size() - 1; i >= 0; i--) {
-
-            HttpFilter currentFilter = filters.get(i);
-            FilterChain nextChain = chain;
-
-            chain = new FilterChain() {
-                @Override
-                public HttpResponse next(HttpRequest request) {
-                    return currentFilter.handle(request, nextChain);
-                }
-            };
-        }
-
-        return chain;
-    }
-}
-
-class HttpRequest {
-    private final String method;
-    private final String path;
-
-    public HttpRequest(String method, String path) {
-        this.method = method;
-        this.path = path;
-    }
-
-    public String path() {
-        return path;
-    }
-
-    public String getMethod() {
-        return method;
-    }
-}
-
-class HttpResponse {
-    private final int statusCode;
-    private final String body;
-
-    public HttpResponse(int statusCode, String body) {
-        this.statusCode = statusCode;
-        this.body = body;
-    }
-
-    public int getStatusCode() {
-        return statusCode;
-    }
-
-    public String getBody() {
-        return body;
-    }
-}
-
-interface HttpFilter {
-    HttpResponse handle(HttpRequest request, FilterChain chain);
-}
-
-interface FilterChain {
-    HttpResponse next(HttpRequest request);
-}
-
-interface TerminalHandler {
-    HttpResponse handle(HttpRequest request);
 }

src/main/java/org/example/server/FilterRegistration.java

@@ -1,9 +1,11 @@
 package org.example.server;
 
+import org.example.filter.Filter;
+
 import java.util.List;
 
 public record FilterRegistration(
-        HttpFilter filter,
+        Filter filter,
         int order,
         List<String> routePatterns
 ) {