8188240: Reflection Proxy should skip static methods

Reviewed-by: mchung, sundar, shade, plevart

src/java.base/share/classes/java/lang/reflect/ProxyGenerator.java

@@ -449,7 +449,9 @@ class ProxyGenerator {
          */
         for (Class<?> intf : interfaces) {
             for (Method m : intf.getMethods()) {
-                addProxyMethod(m, intf);
+                if (!Modifier.isStatic(m.getModifiers())) {
+                    addProxyMethod(m, intf);
+                }
             }
         }
 

test/jdk/java/lang/reflect/Proxy/ProxyClashTest.java

@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/* @test
+ * @bug 8188240
+ * @summary This is a test to ensure that proxies do not try to intercept interface static methods.
+ *
+ * @build ProxyClashTest
+ * @run main ProxyClashTest
+ */
+
+import java.lang.reflect.Method;
+import java.lang.reflect.Proxy;
+import java.util.Observer;
+
+public class ProxyClashTest {
+
+    public interface ClashWithRunnable {
+        static int run() { return 123; }
+
+        static void foo() {}
+    }
+
+    public static void main(String[] args) {
+        System.err.println(
+            "\nDynamic proxy API static method clash test\n");
+
+        Class<?>[] interfaces =
+            new Class<?>[] { ClashWithRunnable.class, Runnable.class, Observer.class };
+
+        ClassLoader loader = ProxyClashTest.class.getClassLoader();
+
+        /*
+         * Generate a proxy class.
+         */
+        Class<?> proxyClass = Proxy.getProxyClass(loader, interfaces);
+        System.err.println("+ generated proxy class: " + proxyClass);
+
+        for (Method method : proxyClass.getDeclaredMethods()) {
+            if (method.getName().equals("run") && method.getReturnType() == int.class) {
+                throw new RuntimeException("proxy intercept a static method");
+            }
+            if (method.getName().equals("foo")) {
+                throw new RuntimeException("proxy intercept a static method");
+            }
+        }
+
+        System.err.println("\nTEST PASSED");
+    }
+}