[PATCH] 8245694 : java.util.Properties.entrySet() does not override java.lang.Object methods

[Rob Spoor]

There's still a little regression there since Java 8, if you add the 
keySet(), values() or entrySet() to the Properties object as either key 
or value; in Java 8 this would cause "(this Collection)" to be included, 
while even with this fix that would cause a StackOverflowError. However, 
given that it's only a corner case for most Collections and Maps in the 
first place, and with Properties objects even more so, I don't think 
anyone would mind this regression.

Rob

On 30/05/2020 20:31, Lisa Li wrote:
> Hi,
> 
> Please help review the fix for JDK-8245694
> <https://bugs.openjdk.java.net/browse/JDK-8245694>.  And this is my very
> first patch submission. I know it's not perfect.
> <https://bugs.openjdk.java.net/browse/JDK-8245694>
> 
> 
> *BUG DESCRIPTION*:
> 
> JDK-8245694 <https://bugs.openjdk.java.net/browse/JDK-8245694> :
> java.util.Properties.entrySet()
> does not override java.lang.Object methods since java 9.
> 
> 
> *PROPOSED FIX*:
> 
> Add delegating overrides for equals(), hashCode(), and toString().
> 
> 
> *PATCH*:
> 
> # HG changeset patch
> # User yuli
> # Date 1590841711 -28800
> #      Sat May 30 20:28:31 2020 +0800
> # Node ID 7dc946e5b5863291fa070bfdbdce48aefbe87b7b
> # Parent  8e28aae5068069e853673148e4d3f44cb50350a7
> 8245694: java.util.Properties.entrySet() does not override Object methods
> Summary: Add missing override methods
> Contributed-by: Yu Li <liyu.italy at gmail.com>
> 
> diff --git a/src/java.base/share/classes/java/util/Properties.java
> b/src/java.base/share/classes/java/util/Properties.java
> --- a/src/java.base/share/classes/java/util/Properties.java
> +++ b/src/java.base/share/classes/java/util/Properties.java
> @@ -1414,6 +1414,21 @@
>               return entrySet.retainAll(c);
>           }
> 
> +         @Override
> +        public boolean equals(Object o) {
> +            return entrySet.equals(o);
> +        }
> +
> +        @Override
> +        public int hashCode() {
> +            return entrySet.hashCode();
> +        }
> +
> +        @Override
> +        public String toString() {
> +            return entrySet.toString();
> +        }
> +
>           @Override
>           public Iterator<Map.Entry<Object, Object>> iterator() {
>               return entrySet.iterator();
> diff --git a/test/jdk/java/util/Properties/PropertiesEntrySetTest.java
> b/test/jdk/java/util/Properties/PropertiesEntrySetTest.java
> new file mode 100644
> --- /dev/null
> +++ b/test/jdk/java/util/Properties/PropertiesEntrySetTest.java
> @@ -0,0 +1,90 @@
> +/*
> + * Copyright (c) 2018, 2019, 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
> + * @summary tests the entrySet() method of Properties class
> + * @author  Yu Li
> + * @bug     8245694
> + */
> +
> +import java.util.Map;
> +import java.util.Properties;
> +import java.util.Set;
> +
> +public class PropertiesEntrySetTest {
> +
> +    public static void main(String[] args) {
> +
> +        testEntrySet();
> +
> +    }
> +
> +    private static void assertTrue(boolean value) {
> +        if (!value) {
> +            throw new RuntimeException("Failure in Properties testing.");
> +        }
> +    }
> +
> +    private static void assertFalse(boolean value) {
> +        if (value) {
> +            throw new RuntimeException("Failure in Properties testing.");
> +        }
> +    }
> +
> +    private static void testEntrySet() {
> +        Properties a = new Properties();
> +        Set<Map.Entry<Object, Object>> aEntrySet = a.entrySet();
> +        assertFalse(aEntrySet.equals(null));
> +        assertTrue(aEntrySet.equals(aEntrySet));
> +
> +        Properties b = new Properties();
> +        Set<Map.Entry<Object, Object>> bEntrySet = b.entrySet();
> +        assertTrue(aEntrySet.equals(bEntrySet));
> +        assertTrue(aEntrySet.hashCode() == bEntrySet.hashCode());
> +
> +        a.setProperty("p1", "1");
> +        assertFalse(aEntrySet.equals(bEntrySet));
> +        assertFalse(bEntrySet.equals(aEntrySet));
> +        assertFalse(aEntrySet.hashCode() == bEntrySet.hashCode());
> +
> +        b.setProperty("p1", "1");
> +        assertTrue(aEntrySet.equals(bEntrySet));
> +        assertTrue(aEntrySet.hashCode() == bEntrySet.hashCode());
> +
> +        Properties c = new Properties();
> +        c.setProperty("p1", "2");
> +        Set<Map.Entry<Object, Object>> cEntrySet = c.entrySet();
> +        assertFalse(cEntrySet.equals(bEntrySet));
> +        assertFalse(cEntrySet.hashCode() == bEntrySet.hashCode());
> +        assertFalse(cEntrySet.equals(aEntrySet));
> +        assertFalse(cEntrySet.hashCode() == aEntrySet.hashCode());
> +
> +        a.setProperty("p2", "2");
> +        Properties d = new Properties();
> +        d.setProperty("p2", "2");
> +        d.setProperty("p1", "1");
> +        Set<Map.Entry<Object, Object>> dEntrySet = d.entrySet();
> +        assertTrue(dEntrySet.equals(aEntrySet));
> +    }
> +}
> 
> Best regards,
> Yu Li