8262277: URLClassLoader.getResource throws undocumented IllegalArgumentException

Reviewed-by: alanb, bchristi, psadhukhan

src/java.base/share/classes/jdk/internal/loader/URLClassPath.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2021, 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
@@ -600,7 +600,7 @@ public class URLClassPath {
             try {
                 url = new URL(base, ParseUtil.encodePath(name, false));
             } catch (MalformedURLException e) {
-                throw new IllegalArgumentException("name");
+                return null;
             }
 
             try {
@@ -636,7 +636,7 @@ public class URLClassPath {
             try {
                 url = new URL(base, ParseUtil.encodePath(name, false));
             } catch (MalformedURLException e) {
-                throw new IllegalArgumentException("name");
+                return null;
             }
             final URLConnection uc;
             try {

test/jdk/java/net/URLClassLoader/FindResourceDoesNotThrowException.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2021, 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 8262277
+ * @summary Test if URLClassLoader throws IllegalArgumentException when getting
+ * or finding resources.
+ */
+
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.util.Enumeration;
+
+public class FindResourceDoesNotThrowException {
+    public static void main(String[] args) throws Exception {
+        // URL ends in slash, does not start with file: or jar:
+        URL url = new URL("https://127.0.0.1/");
+        // resource name is not a valid url component
+        String resource = "c:/windows";
+        try (URLClassLoader urlClassLoader = new URLClassLoader(new URL[]{url})) {
+            if (urlClassLoader.findResource(resource) != null) {
+                throw new RuntimeException("findResource should return null");
+            }
+            if (urlClassLoader.getResource(resource) != null) {
+                throw new RuntimeException("getResource should return null");
+            }
+            if (urlClassLoader.findResources(resource).hasMoreElements()) {
+                throw new RuntimeException("findResources should return an empty enumeration");
+            }
+            if (urlClassLoader.getResources(resource).hasMoreElements()) {
+                throw new RuntimeException("getResources should return an empty enumeration");
+            }
+        }
+    }
+    private FindResourceDoesNotThrowException() {}
+}