Cleanup many warnings from ee10 and ee11 servlet

jetty-ee10/jetty-ee10-servlet/src/main/java/org/eclipse/jetty/ee10/servlet/BaseHolder.java

@@ -28,8 +28,6 @@
 import org.slf4j.LoggerFactory;
 
 /**
- * AbstractHolder
- *
  * Base class for all servlet-related classes that may be lazily instantiated  (eg servlet, filter,
  * listener), and/or require metadata to be held regarding their origin
  * (web.xml, annotation, programmatic api etc).
@@ -86,7 +84,7 @@ public void doStart()
     {
         //if no class already loaded and no classname, make permanently unavailable
         if (_class == null && (_className == null || _className.isEmpty()))
-            throw new UnavailableException("No class in holder " + toString());
+            throw new UnavailableException("No class in holder " + this);
 
         //try to load class
         if (_class == null)
@@ -100,7 +98,7 @@ public void doStart()
             catch (Exception e)
             {
                 LOG.warn("Unable to load class {}", _className, e);
-                throw new UnavailableException("Class loading error for holder " + toString());
+                throw new UnavailableException("Class loading error for holder " + this);
             }
         }
     }
@@ -173,27 +171,31 @@ protected void illegalStateIfContextStarted()
 
     protected void setInstance(T instance)
     {
-        try (AutoLock l = lock())
+        try (AutoLock ignored = lock())
         {
             _instance = instance;
             if (instance == null)
                 setHeldClass(null);
             else
-                setHeldClass((Class<T>)instance.getClass());
+            {
+                @SuppressWarnings("unchecked")
+                Class<? extends T> clazz = (Class<? extends T>)instance.getClass();
+                setHeldClass(clazz);
+            }
         }
     }
 
     protected T getInstance()
     {
-        try (AutoLock l = lock())
+        try (AutoLock ignored = lock())
         {
             return _instance;
         }
     }
 
     protected T createInstance() throws Exception
     {
-        try (AutoLock l = lock())
+        try (AutoLock ignored = lock())
         {
             ServletContext ctx = getServletContext();
             if (ctx == null)
@@ -241,7 +243,7 @@ public ServletContextHandler getServletContextHandler()
      */
     public boolean isInstance()
     {
-        try (AutoLock l = lock())
+        try (AutoLock ignored = lock())
         {
             return _instance != null;
         }

jetty-ee10/jetty-ee10-servlet/src/main/java/org/eclipse/jetty/ee10/servlet/ContentProducer.java

@@ -34,7 +34,6 @@ public interface ContentProducer
     /**
      * Fail all content currently available in this {@link ContentProducer} instance
      * as well as in the underlying {@link Content.Source}.
-     *
      * This call is always non-blocking.
      * Doesn't change state.
      * @return true if EOF was reached.
@@ -50,7 +49,6 @@ public interface ContentProducer
 
     /**
      * Get the byte count produced by the underlying {@link Content.Source}.
-     *
      * This call is always non-blocking.
      * Doesn't change state.
      * @return the byte count produced by the underlying {@link Content.Source}.
@@ -60,7 +58,6 @@ public interface ContentProducer
     /**
      * Get the byte count that can immediately be read from this
      * {@link ContentProducer} instance or the underlying {@link Content.Source}.
-     *
      * This call is always non-blocking.
      * Doesn't change state.
      * @return the available byte count.
@@ -70,7 +67,6 @@ public interface ContentProducer
     /**
      * Check if this {@link ContentProducer} instance contains some
      * content chunk without querying the underlying {@link Content.Source}.
-     *
      * This call is always non-blocking.
      * Doesn't change state.
      * Doesn't query the HttpChannel.

jetty-ee10/jetty-ee10-servlet/src/main/java/org/eclipse/jetty/ee10/servlet/CrossContextDispatcher.java

@@ -144,7 +144,7 @@ public HttpURI getHttpURI()
         }
     }
 
-    private class IncludeResponse extends ServletCoreResponse
+    private static class IncludeResponse extends ServletCoreResponse
     {
         public IncludeResponse(Request coreRequest, HttpServletResponse httpServletResponse)
         {
@@ -256,7 +256,6 @@ public void include(ServletRequest servletRequest, ServletResponse servletRespon
     {
         HttpServletRequest httpServletRequest = (servletRequest instanceof HttpServletRequest) ? ((HttpServletRequest)servletRequest) : new ServletRequestHttpWrapper(servletRequest);
         HttpServletResponse httpServletResponse = (servletResponse instanceof HttpServletResponse) ? (HttpServletResponse)servletResponse : new ServletResponseHttpWrapper(servletResponse);
-        ServletContextResponse servletContextResponse = ServletContextResponse.getServletContextResponse(servletResponse);
 
         IncludeRequest includeRequest = new IncludeRequest(httpServletRequest);
         IncludeResponse includeResponse = new IncludeResponse(includeRequest, httpServletResponse);

jetty-ee10/jetty-ee10-servlet/src/main/java/org/eclipse/jetty/ee10/servlet/DecoratingListener.java

@@ -145,7 +145,9 @@ public <T> T decorate(T o)
         {
             try
             {
-                return (T)_decorate.invoke(_object, o);
+                @SuppressWarnings("unchecked")
+                T decorated = (T)_decorate.invoke(_object, o);
+                return decorated;
             }
             catch (Throwable t)
             {

jetty-ee10/jetty-ee10-servlet/src/main/java/org/eclipse/jetty/ee10/servlet/Dispatcher.java

@@ -747,12 +747,9 @@ public Enumeration<String> getAttributeNames()
 
     private class ErrorRequest extends ParameterRequestWrapper
     {
-        private final HttpServletRequest _httpServletRequest;
-
         public ErrorRequest(HttpServletRequest httpRequest)
         {
             super(httpRequest);
-            _httpServletRequest = httpRequest;
         }
 
         @Override

jetty-ee10/jetty-ee10-servlet/src/main/java/org/eclipse/jetty/ee10/servlet/ErrorHandler.java

@@ -68,15 +68,11 @@ public ErrorHandler()
 
     public boolean errorPageForMethod(String method)
     {
-        switch (method)
+        return switch (method)
         {
-            case "GET":
-            case "POST":
-            case "HEAD":
-                return true;
-            default:
-                return false;
-        }
+            case "GET", "POST", "HEAD" -> true;
+            default -> false;
+        };
     }
 
     @Override

jetty-ee10/jetty-ee10-servlet/src/main/java/org/eclipse/jetty/ee10/servlet/FilterHolder.java

@@ -106,7 +106,7 @@ public void doStart()
     @Override
     public void initialize() throws Exception
     {
-        try (AutoLock l = lock())
+        try (AutoLock ignored = lock())
         {
             if (_filter != null)
                 return;
@@ -140,7 +140,7 @@ public void initialize() throws Exception
     @Override
     protected Filter createInstance() throws Exception
     {
-        try (AutoLock l = lock())
+        try (AutoLock ignored = lock())
         {
             Filter filter = super.createInstance();
             if (filter == null)
@@ -392,7 +392,7 @@ public void destroy()
         @Override
         public String toString()
         {
-            return String.format("%s:%s", this.getClass().getSimpleName(), _filter.toString());
+            return String.format("%s:%s", this.getClass().getSimpleName(), _filter);
         }
     }
 }

jetty-ee10/jetty-ee10-servlet/src/main/java/org/eclipse/jetty/ee10/servlet/FilterMapping.java

@@ -69,21 +69,14 @@ public static DispatcherType dispatch(String type)
      */
     public static int dispatch(DispatcherType type)
     {
-        switch (type)
+        return switch (type)
         {
-            case REQUEST:
-                return REQUEST;
-            case ASYNC:
-                return ASYNC;
-            case FORWARD:
-                return FORWARD;
-            case INCLUDE:
-                return INCLUDE;
-            case ERROR:
-                return ERROR;
-            default:
-                throw new IllegalStateException(type.toString());
-        }
+            case REQUEST -> REQUEST;
+            case ASYNC -> ASYNC;
+            case FORWARD -> FORWARD;
+            case INCLUDE -> INCLUDE;
+            case ERROR -> ERROR;
+        };
     }
 
     /**
@@ -94,21 +87,15 @@ public static int dispatch(DispatcherType type)
      */
     public static DispatcherType dispatch(int type)
     {
-        switch (type)
+        return switch (type)
         {
-            case REQUEST:
-                return DispatcherType.REQUEST;
-            case ASYNC:
-                return DispatcherType.ASYNC;
-            case FORWARD:
-                return DispatcherType.FORWARD;
-            case INCLUDE:
-                return DispatcherType.INCLUDE;
-            case ERROR:
-                return DispatcherType.ERROR;
-            default:
-                throw new IllegalArgumentException(Integer.toString(type));
-        }
+            case REQUEST -> DispatcherType.REQUEST;
+            case ASYNC -> DispatcherType.ASYNC;
+            case FORWARD -> DispatcherType.FORWARD;
+            case INCLUDE -> DispatcherType.INCLUDE;
+            case ERROR -> DispatcherType.ERROR;
+            default -> throw new IllegalArgumentException(Integer.toString(type));
+        };
     }
 
     private int _dispatches = DEFAULT;
@@ -132,9 +119,9 @@ boolean appliesTo(String path, int type)
     {
         if (appliesTo(type))
         {
-            for (int i = 0; i < _pathSpecs.length; i++)
+            for (String pathSpec : _pathSpecs)
             {
-                if (_pathSpecs[i] != null && ServletPathSpec.match(_pathSpecs[i], path, true))
+                if (pathSpec != null && ServletPathSpec.match(pathSpec, path, true))
                     return true;
             }
         }
@@ -152,10 +139,10 @@ boolean appliesTo(String path, int type)
     boolean appliesTo(int type)
     {
         FilterHolder holder = _holder;
-        if (_holder == null)
+        if (holder == null)
             return false;
         if (_dispatches == 0)
-            return type == REQUEST || type == ASYNC && (_holder != null && _holder.isAsyncSupported());
+            return type == REQUEST || type == ASYNC && holder.isAsyncSupported();
         return (_dispatches & type) != 0;
     }
 

jetty-ee10/jetty-ee10-servlet/src/main/java/org/eclipse/jetty/ee10/servlet/Holder.java

@@ -29,8 +29,6 @@
 import org.slf4j.LoggerFactory;
 
 /**
- * Holder
- *
  * Specialization of AbstractHolder for servlet-related classes that
  * have init-params etc
  *
@@ -41,7 +39,7 @@ public abstract class Holder<T> extends BaseHolder<T>
 {
     private static final Logger LOG = LoggerFactory.getLogger(Holder.class);
 
-    private final Map<String, String> _initParams = new HashMap<String, String>(3);
+    private final Map<String, String> _initParams = new HashMap<>(3);
     private String _displayName;
     private boolean _asyncSupported;
     private String _name;
@@ -69,15 +67,11 @@ public String getDisplayName()
 
     public String getInitParameter(String param)
     {
-        if (_initParams == null)
-            return null;
-        return (String)_initParams.get(param);
+        return _initParams.get(param);
     }
 
     public Enumeration<String> getInitParameterNames()
     {
-        if (_initParams == null)
-            return Collections.enumeration(Collections.EMPTY_LIST);
         return Collections.enumeration(_initParams.keySet());
     }
 
@@ -96,7 +90,7 @@ public String getName()
     @Override
     protected void setInstance(T instance)
     {
-        try (AutoLock l = lock())
+        try (AutoLock ignored = lock())
         {
             super.setInstance(instance);
             if (getName() == null)
@@ -277,7 +271,7 @@ public Set<String> setInitParameters(Map<String, String> initParameters)
                 if (Holder.this.getInitParameter(entry.getKey()) != null)
                 {
                     if (clash == null)
-                        clash = new HashSet<String>();
+                        clash = new HashSet<>();
                     clash.add(entry.getKey());
                 }
             }