Issue #5137 - Adding test case to demonstrate usage.

+ Partially reverting change in commit 31175e9 Signed-off-by: Joakim Erdfelt <joakim.erdfelt@gmail.com>
jetty · Sep 16, 2020 · 61ffdc2 · 61ffdc2
1 parent 31175e9
commit 61ffdc2
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Showing 5 changed files with 355 additions and 24 deletions.
diff --git a/jetty-servlet/src/main/java/org/eclipse/jetty/servlet/BaseHolder.java b/jetty-servlet/src/main/java/org/eclipse/jetty/servlet/BaseHolder.java
@@ -19,6 +19,7 @@
 package org.eclipse.jetty.servlet;
 
 import java.io.IOException;
+import java.util.function.BiFunction;
 import javax.servlet.ServletContext;
 import javax.servlet.UnavailableException;
 
@@ -185,25 +186,30 @@ public synchronized boolean isInstance()
         return _instance != null;
     }
 
-    protected T wrap(T component, Class<? extends BaseWrapFunction<T>> wrapperType)
+    protected <C, W> C wrap(final C component, final Class<W> wrapperFunctionType, final BiFunction<W, C, C> function)
     {
+        C ret = component;
         ServletContextHandler contextHandler = getServletHandler().getServletContextHandler();
         if (contextHandler != null)
         {
-            for (BaseWrapFunction<T> wrapperFunction : contextHandler.getBeans(wrapperType))
-                component = wrapperFunction.wrap(component);
+            for (W wrapperFunction : contextHandler.getBeans(wrapperFunctionType))
+            {
+                ret = function.apply(wrapperFunction, ret);
+            }
         }
-        return component;
+        return ret;
     }
 
-    protected T unwrap(T component)
+    protected <C> C unwrap(final C component)
     {
-        while (component instanceof Wrapped)
+        C ret = component;
+
+        while (ret instanceof Wrapped)
         {
             // noinspection unchecked,rawtypes
-            component = (T)((Wrapped<T>)component).getWrapped();
+            ret = (C)((Wrapped)ret).getWrapped();
         }
-        return component;
+        return ret;
     }
 
     @Override
@@ -218,13 +224,8 @@ public String dump()
         return Dumpable.dump(this);
     }
 
-    public interface BaseWrapFunction<T>
-    {
-        T wrap(T component);
-    }
-
-    interface Wrapped<T>
+    interface Wrapped<C>
     {
-        T getWrapped();
+        C getWrapped();
     }
 }
diff --git a/jetty-servlet/src/main/java/org/eclipse/jetty/servlet/FilterHolder.java b/jetty-servlet/src/main/java/org/eclipse/jetty/servlet/FilterHolder.java
@@ -132,7 +132,7 @@ public void initialize() throws Exception
                     throw ex;
                 }
             }
-            _filter = wrap(_filter, WrapFunction.class);
+            _filter = wrap(_filter, WrapFunction.class, WrapFunction::wrapFilter);
             _config = new Config();
             if (LOG.isDebugEnabled())
                 LOG.debug("Filter.init {}", _filter);
@@ -297,8 +297,16 @@ public String getFilterName()
      * (before their {@link Filter#init(FilterConfig)} method is called)
      * </p>
      */
-    public interface WrapFunction extends BaseWrapFunction<Filter>
-    {}
+    public interface WrapFunction
+    {
+        /**
+         * Optionally wrap the Filter.
+         *
+         * @param filter the Filter being passed in.
+         * @return the Filter (extend from {@link FilterHolder.Wrapper} if you do wrap the Filter)
+         */
+        Filter wrapFilter(Filter filter);
+    }
 
     public static class Wrapper implements Filter, Wrapped<Filter>
     {

diff --git a/jetty-servlet/src/main/java/org/eclipse/jetty/servlet/ListenerHolder.java b/jetty-servlet/src/main/java/org/eclipse/jetty/servlet/ListenerHolder.java
@@ -102,7 +102,7 @@ public void doStart() throws Exception
                     throw ex;
                 }
             }
-            _listener = wrap(_listener, WrapperFunction.class);
+            _listener = wrap(_listener, WrapFunction.class, WrapFunction::wrapEventListener);
             contextHandler.addEventListener(_listener);
         }
     }
@@ -141,8 +141,17 @@ public String toString()
      * they are used for the first time.
      * </p>
      */
-    public interface WrapperFunction extends BaseWrapFunction<EventListener>
-    {}
+    public interface WrapFunction
+    {
+        /**
+         * Optionally wrap the Servlet EventListener.
+         *
+         * @param listener the Servlet EventListener being passed in.
+         * @return the Servlet EventListener (extend from {@link ListenerHolder.Wrapper}
+         * if you do wrap the Servlet EventListener)
+         */
+        EventListener wrapEventListener(EventListener listener);
+    }
 
     public static class Wrapper implements EventListener, Wrapped<EventListener>
     {

diff --git a/jetty-servlet/src/main/java/org/eclipse/jetty/servlet/ServletHolder.java b/jetty-servlet/src/main/java/org/eclipse/jetty/servlet/ServletHolder.java
@@ -595,7 +595,7 @@ else if (_forcedPath != null)
                 detectJspContainer();
 
             initMultiPart();
-            _servlet = wrap(_servlet, WrapperFunction.class);
+            _servlet = wrap(_servlet, WrapFunction.class, WrapFunction::wrapServlet);
 
             if (LOG.isDebugEnabled())
                 LOG.debug("Servlet.init {} for {}", _servlet, getName());
@@ -1281,8 +1281,16 @@ public UnavailableException getUnavailableException()
      * (before their {@link Servlet#init(ServletConfig)} method is called)
      * </p>
      */
-    public interface WrapperFunction extends BaseWrapFunction<Servlet>
-    {}
+    public interface WrapFunction
+    {
+        /**
+         * Optionally wrap the Servlet.
+         *
+         * @param servlet the servlet being passed in.
+         * @return the servlet (extend from {@link ServletHolder.Wrapper} if you do wrap the Servlet)
+         */
+        Servlet wrapServlet(Servlet servlet);
+    }
 
     public static class Wrapper implements Servlet, Wrapped<Servlet>
     {