8129215: com.sun.jmx.mbeanserver.Introspector may provide results inconsistent with the JavaBeans Introspector

Reviewed-by: dfuchs

jdk/src/java.management/share/classes/com/sun/jmx/mbeanserver/Introspector.java

@@ -552,8 +552,10 @@ public class Introspector {
                 // Java Beans introspection
                 //
                 Class<?> clazz = complex.getClass();
-                Method readMethod = JavaBeansAccessor.getReadMethod(clazz, element);
-                if (readMethod == null) {
+                Method readMethod;
+                if (JavaBeansAccessor.isAvailable()) {
+                    readMethod = JavaBeansAccessor.getReadMethod(clazz, element);
+                } else {
                     // Java Beans not available so use simple introspection
                     // to locate method
                     readMethod = SimpleIntrospector.getReadMethod(clazz, element);
@@ -676,7 +678,12 @@ public class Introspector {
          * {@code null} if no method is found.
          */
         static Method getReadMethod(Class<?> clazz, String property) {
-            // first character in uppercase (compatibility with JavaBeans)
+            if (Character.isUpperCase(property.charAt(0))) {
+                // the property name must start with a lower-case letter
+                return null;
+            }
+            // first character after 'get/is' prefix must be in uppercase
+            // (compatibility with JavaBeans)
             property = property.substring(0, 1).toUpperCase(Locale.ENGLISH) +
                 property.substring(1);
             String getMethod = GET_METHOD_PREFIX + property;

jdk/test/com/sun/jmx/mbeanserver/introspector/BeanClass.java

@@ -0,0 +1,28 @@
+/*
+ * Copyright (c) 2015, 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.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * 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.
+ */
+public class BeanClass {
+    public int getNumber() {return 1;}
+    public boolean isAvailable() {return false;}
+}

jdk/test/com/sun/jmx/mbeanserver/introspector/SimpleIntrospectorTest.java

@@ -0,0 +1,104 @@
+
+/*
+ * Copyright (c) 2015, 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.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * 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.
+ */
+import java.lang.reflect.Method;
+
+/*
+ * @test
+ * @bug 8129215
+ * @summary The test checks whether the SimpleIntrospector is honoring the
+ *          the JavaBeans property naming convention of always starting
+ *          with a lower-case letter
+ *
+ * @author Jaroslav Bachorik
+ * @modules java.management
+ * @run clean SimpleIntrospectorTest
+ * @run build SimpleIntrospectorTest BeanClass
+ * @run main SimpleIntrospectorTest
+ */
+public class SimpleIntrospectorTest {
+    private static Method INTROSPECT_GETTER;
+
+    public static void main(String ... args) throws Exception {
+        Class clz = Class.forName(
+            "com.sun.jmx.mbeanserver.Introspector$SimpleIntrospector"
+        );
+        INTROSPECT_GETTER = clz.getDeclaredMethod(
+            "getReadMethod",
+            Class.class,
+            String.class
+        );
+        INTROSPECT_GETTER.setAccessible(true);
+        boolean result = true;
+        result &= checkNumberValid();
+        result &= checkNumberInvalid();
+        result &= checkAvailableValid();
+        result &= checkAvailableInvalid();
+
+        if (!result) {
+            throw new Error();
+        }
+    }
+
+    private static boolean checkNumberValid() throws Exception {
+        return checkGetter(false, "number");
+    }
+
+    private static boolean checkNumberInvalid() throws Exception {
+        return checkGetter(true, "Number");
+    }
+
+    private static boolean checkAvailableValid() throws Exception {
+        return checkGetter(false, "available");
+    }
+
+    private static boolean checkAvailableInvalid() throws Exception {
+        return checkGetter(true, "Available");
+    }
+
+    private static boolean checkGetter(boolean nullExpected, String name)
+    throws Exception {
+        Method m = getReadMethod(BeanClass.class, name);
+        boolean result = (m != null);
+        if (nullExpected) result = !result;
+
+        if (result) {
+            return true;
+        }
+        if (nullExpected) {
+            System.err.println("SimpleIntrospector resolved an unknown getter " +
+                               "for attribute '"+ name +"'");
+        } else {
+            System.err.println("SimpleIntrospector fails to resolve getter " +
+                               "for attribute '"+ name +"'");
+        }
+        return false;
+    }
+
+    private static Method getReadMethod(Class clz, String attr)
+    throws Exception {
+        return (Method)INTROSPECT_GETTER.invoke(null, clz, attr);
+    }
+}