[LANG-1685] [JDK17] ToStringBuilder.reflectionToString fails with InaccessibleObjectException on java.lang classes

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 3.12.0
• Component/s: lang.builder.*

Language

Java

• Assignee: Unassigned
• Reporter: David Connard
• Created: 30/Mar/22 01:00
• Updated: 30/Dec/22 20:57

Description

JDK17 prevents reflective access to java.lang classes by default.

The following code fails on JDK17+

System.out.println("boom = " + ToStringBuilder.reflectionToString(Set.of(123))); 

I understand that we can "--add-opens" (eg. as you've done for hbase builds in https://github.com/jojochuang/hbase/commit/b909db7ca7c221308ad5aba1ea58317c77358b94) ... but, ideally, that should not be a standard requirement to run an application that uses ToStringBuilder.reflectionToString() on JDK17+

The following sample code appears to work for our use-case, albeit with some additional spurious output on the object.  It catches the exception and just dumps a raw object toString() instead.  You probably want to improve on this.

ReflectionToStringBuilder jdk17SafeToStringBuilder = new ReflectionToStringBuilder(obj) {
    protected void appendFieldsIn(final Class<?> clazz) {
        if (clazz.isArray()) {
            this.reflectionAppendArray(this.getObject());
            return;
        }
        // The elements in the returned array are not sorted and are not in any particular order.
        final Field[] fields = clazz.getDeclaredFields();
        Arrays.sort(fields, Comparator.comparing(Field::getName));
        try {
            // first, check that we can delve into the fields.  With JDK17+, we cannot do this by default on
            // various JDK classes
            AccessibleObject.setAccessible(fields, true);
        } catch (InaccessibleObjectException ioEx) {
            // JDK 17 - prevents access to fields.  We'll ignore this, and assume these have a decent toString() and not reflect into them
            this.appendToString(Objects.toString(obj));
            return;
        }
        for (final Field field : fields) {
            final String fieldName = field.getName();
            if (this.accept(field)) {
                try {
                    // Warning: Field.get(Object) creates wrappers objects
                    // for primitive types.
                    final Object fieldValue = this.getValue(field);
                    if (!isExcludeNullValues() || fieldValue != null) {
                        this.append(fieldName, fieldValue, !field.isAnnotationPresent(ToStringSummary.class));
                    }
                } catch (final IllegalAccessException ex) {
                    //this can't happen. Would get a Security exception
                    // instead
                    //throw a runtime exception in case the impossible
                    // happens.
                    throw new InternalError("Unexpected IllegalAccessException: " + ex.getMessage());
                }
            }
        }
    }
};