MethodUtils cannot find or invoke vararg methods of interface types

Author: garydgregory

src/changes/changes.xml

@@ -52,7 +52,8 @@ The <action> type attribute can be add,update,fix,remove.
     <action                   type="fix" dev="ggregory" due-to="Gary Gregory">MethodUtils cannot find or invoke a public method on a public class implemented in its package-private superclass.</action>
     <action                   type="fix" dev="ggregory" due-to="Stanislav Fort, Gary Gregory">org.apache.commons.lang3.concurrent.AtomicSafeInitializer.get() can spin internally if the FailableSupplier given to org.apache.commons.lang3.concurrent.AbstractConcurrentInitializer.AbstractBuilder.setInitializer(FailableSupplier) throws a RuntimeException.</action>
     <action issue="LANG-1783" type="fix" dev="ggregory" due-to="Arnout Engelen, Stanislav Fort, Gary Gregory">WordUtils.containsAllWords​() may throw PatternSyntaxException.</action>
-    <action                   type="fix" dev="ggregory" due-to="Joe Ferner, Gary Gregory">MethodUtils cannot find or invoke a vararg method without providing vararg types or values #1427.</action>
+    <action                   type="fix" dev="ggregory" due-to="Joe Ferner, Gary Gregory">MethodUtils cannot find or invoke vararg methods without providing vararg types or values #1427.</action>
+    <action                   type="fix" dev="ggregory" due-to="Joe Ferner, Gary Gregory">MethodUtils cannot find or invoke vararg methods of interface types.</action>
     <!-- FIX Javadoc -->
     <action                   type="fix" dev="ggregory" due-to="Gary Gregory">[javadoc] General improvements.</action>
     <action                   type="fix" dev="ggregory" due-to="Gary Gregory">[javadoc] Fix thrown exception documentation for org.apache.commons.lang3.reflect.MethodUtils.getMethodObject(Class&lt;?&gt;, String, Class&lt;?&gt;...).</action>

src/main/java/org/apache/commons/lang3/reflect/MethodUtils.java

@@ -358,7 +358,7 @@ public static Method getMatchingAccessibleMethod(final Class<?> cls, final Strin
                     final String requestTypeSuperClassName = requestLastType == null ? null
                             : requestLastType.getSuperclass() != null ? requestLastType.getSuperclass().getName() : null;
                     if (requestTypeName != null && requestTypeSuperClassName != null && !varVargTypeName.equals(requestTypeName)
-                            && !varVargTypeName.equals(requestTypeSuperClassName)) {
+                            && !varVargTypeName.equals(requestTypeSuperClassName) && !componentType.isAssignableFrom(requestLastType)) {
                         return null;
                     }
                 }

src/test/java/org/apache/commons/lang3/reflect/MethodUtilsTest.java

@@ -176,6 +176,14 @@ private interface PrivateEmptyInterface {
         // empty
     }
 
+    public static class PublicImpl1OfPackagePrivateEmptyInterface implements PackagePrivateEmptyInterface {
+        // empty
+    }
+
+    public static class PublicImpl2OfPackagePrivateEmptyInterface implements PackagePrivateEmptyInterface {
+        // empty
+    }
+
     public static class TestBean {
 
         public static String bar() {
@@ -248,16 +256,24 @@ public static void oneParameterStatic(final String s) {
             // empty
         }
 
-        public static String staticIntStringVarArg(final int intArg, final String... args) {
-            return "static int, String...";
+        public static String staticIntIntVarArg(final int intArg, final int... args) {
+            return "static int, int...";
         }
 
         public static String staticIntLongVarArg(final int intArg, final long... args) {
             return "static int, long...";
         }
 
-        public static String staticIntIntVarArg(final int intArg, final int... args) {
-            return "static int, int...";
+        public static String staticIntStringVarArg(final int intArg, final String... args) {
+            return "static int, String...";
+        }
+
+        public static String staticPackagePrivateEmptyInterface(final PackagePrivateEmptyInterface... args) {
+            return "static PackagePrivateEmptyInterface...";
+        }
+
+        public String packagePrivateEmptyInterface(final PackagePrivateEmptyInterface... args) {
+            return "PackagePrivateEmptyInterface...";
         }
 
         public static String varOverload(final Boolean... args) {
@@ -385,16 +401,16 @@ public String foo(final String... s) {
             return "foo(String...)";
         }
 
-        public String intStringVarArg(final int intArg, final String... args) {
-            return "int, String...";
+        public String intIntVarArg(final int intArg, final int... args) {
+            return "int, int...";
         }
 
         public String intLongVarArg(final int intArg, final long... args) {
             return "int, long...";
         }
 
-        public String intIntVarArg(final int intArg, final int... args) {
-            return "int, int...";
+        public String intStringVarArg(final int intArg, final String... args) {
+            return "int, String...";
         }
 
         public void oneParameter(final String s) {
@@ -1238,6 +1254,31 @@ void testInvokeStaticMethod1PlusVarArgs() throws Exception {
         assertThrows(NoSuchMethodException.class, () -> MethodUtils.invokeMethod(testBean, "staticIntIntVarArg", 1, "s1", 5));
     }
 
+    @Test
+    void testInvokeStaticMethodVarArgsOfInterface() throws Exception {
+        // staticPackagePrivateEmptyInterface
+        assertEquals("static PackagePrivateEmptyInterface...", MethodUtils.invokeStaticMethod(TestBean.class, "staticPackagePrivateEmptyInterface",
+                new PublicImpl1OfPackagePrivateEmptyInterface(), new PublicImpl2OfPackagePrivateEmptyInterface()));
+        assertEquals("static PackagePrivateEmptyInterface...",
+                MethodUtils.invokeStaticMethod(TestBean.class, "staticPackagePrivateEmptyInterface", new PackagePrivateEmptyInterface() {
+                    // empty
+                }, new PackagePrivateEmptyInterface() {
+                    // empty
+                }));
+    }
+
+    @Test
+    void testInvokeMethodVarArgsOfInterface() throws Exception {
+        // packagePrivateEmptyInterface
+        assertEquals("PackagePrivateEmptyInterface...", MethodUtils.invokeMethod(testBean, "packagePrivateEmptyInterface",
+                new PublicImpl1OfPackagePrivateEmptyInterface(), new PublicImpl2OfPackagePrivateEmptyInterface()));
+        assertEquals("PackagePrivateEmptyInterface...", MethodUtils.invokeMethod(testBean, "packagePrivateEmptyInterface", new PackagePrivateEmptyInterface() {
+            // empty
+        }, new PackagePrivateEmptyInterface() {
+            // empty
+        }));
+    }
+
     @Test
     void testNullArgument() {
         expectMatchingAccessibleMethodParameterTypes(TestBean.class, "oneParameter", singletonArray(null), singletonArray(String.class));