Fix #313. Add inner class support to ImportHandler

Also clarifies that ImportHandler expects the canonical class name where
a full class name is required.

Author: markt-asf

api/src/main/java/jakarta/el/ImportHandler.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012, 2019 Oracle and/or its affiliates and others.
+ * Copyright (c) 2012, 2025 Oracle and/or its affiliates and others.
  * All rights reserved.
  *
  * This program and the accompanying materials are made available under the
@@ -14,7 +14,6 @@
  *
  * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
  */
-
 package jakarta.el;
 
 import static java.lang.reflect.Modifier.isAbstract;
@@ -47,7 +46,7 @@ public class ImportHandler {
     /**
      * Import a static field or method.
      *
-     * @param name The static member name, including the full class name, to be imported
+     * @param name The static member name, including the full class name (in canonical form), to be imported
      * @throws ELException if the name does not include a ".".
      */
     public void importStatic(String name) throws ELException {
@@ -65,7 +64,7 @@ public void importStatic(String name) throws ELException {
     /**
      * Import a class.
      *
-     * @param name The full class name of the class to be imported
+     * @param name The full class name (in canonical form) of the class to be imported
      * @throws ELException if the name does not include a ".".
      */
     public void importClass(String name) throws ELException {
@@ -144,6 +143,25 @@ private Class<?> resolveClassFor(String className) {
         if (c != null) {
             checkModifiers(c.getModifiers());
             classMap.put(className, c);
+            return c;
+        }
+
+        // Might be an inner class
+        StringBuilder sb = new StringBuilder(className);
+        int replacementPosition = sb.lastIndexOf(".");
+        while (replacementPosition > -1) {
+            sb.setCharAt(replacementPosition, '$');
+            c = getClassFor(sb.toString());
+            if (c != null) {
+                checkModifiers(c.getModifiers());
+                classMap.put(sb.toString(), c);
+                break;
+            }
+            replacementPosition = sb.lastIndexOf(".", replacementPosition);
+        }
+
+        if (c == null) {
+            notAClass.add(className);
         }
 
         return c;
@@ -155,11 +173,11 @@ private Class<?> getClassFor(String className) {
                 return Class.forName(className, false, Thread.currentThread().getContextClassLoader());
                 // Some operating systems have case-insensitive path names. An example is Windows if className is
                 // attempting to be resolved from a wildcard import a java.lang.NoClassDefFoundError may be thrown as
-                // the expected case for the type likely doesn't match. See 
-                // https://bugs.java.com/bugdatabase/view_bug.do?bug_id=8024775 and 
+                // the expected case for the type likely doesn't match. See
+                // https://bugs.java.com/bugdatabase/view_bug.do?bug_id=8024775 and
                 // https://bugs.openjdk.java.net/browse/JDK-8133522.
             } catch (ClassNotFoundException | NoClassDefFoundError ex) {
-                notAClass.add(className);
+                // Ignore
             }
         }
 

api/src/test/java/jakarta/el/TestImportHandler.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2025 Contributors to the Eclipse Foundation
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0, which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * This Source Code may also be made available under the following Secondary
+ * Licenses when the conditions for such availability set forth in the
+ * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
+ * version 2 with the GNU Classpath Exception, which is available at
+ * https://www.gnu.org/software/classpath/license.html.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
+ */
+package jakarta.el;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+public class TestImportHandler {
+
+    /*
+     * https://github.com/jakartaee/expression-language/issues/313
+     */
+    @Test
+    public void testResolveInnerClass() throws Exception {
+        ImportHandler importHandler = new ImportHandler();
+
+        importHandler.importClass("jakarta.el.TesterUtil.Numbers");
+        Class<?> clazz = importHandler.resolveClass("Numbers");
+
+        Assertions.assertEquals(TesterUtil.Numbers.class, clazz);
+    }
+}

api/src/test/java/jakarta/el/TesterUtil.java

@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2025 Contributors to the Eclipse Foundation
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0, which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * This Source Code may also be made available under the following Secondary
+ * Licenses when the conditions for such availability set forth in the
+ * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
+ * version 2 with the GNU Classpath Exception, which is available at
+ * https://www.gnu.org/software/classpath/license.html.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
+ */
+package jakarta.el;
+
+public class TesterUtil {
+
+    public enum Numbers {
+        ONE,
+        TWO,
+        THREE
+    }
+}

spec/src/main/asciidoc/ELSpec.adoc

@@ -2,7 +2,7 @@
 :sectnums!:
 == Jakarta Expression Language, Version 6.1
 
-Copyright (c) 2013, 2024 Oracle and/or its affiliates and others.
+Copyright (c) 2013, 2025 Oracle and/or its affiliates and others.
 All rights reserved.
 
 Eclipse is a registered trademark of the Eclipse Foundation. Jakarta
@@ -3000,6 +3000,10 @@ This appendix is non-normative.
 
 === Changes between 6.1 and 6.0
 
+* https://github.com/jakartaee/expression-language/issues/313[#313]
+  Add support for inner classes when using the `ImportHandler` and clarify that
+  the import handler expects canonical class names where full class names are
+  required.
 
 === Changes between 6.0 and 5.0