与<代码>Map相比,/code>上的区别在于store(>/load( 提供一定专用序列化规则>的方法。 这些规则没有(也不会)改变各支离破碎版本。 e.g.

• Storing pairs like prop=value
• Escaping rules for unicode and special characters.
• Adding optional comment on top

Unfortunately the above 3 parts of the functionality are hidden inside private methods, and cannot be easily re-used inside extended or alternative implementations that wish to use different internal data-structures (e.g. for keeping properties sorted).

因此,剩下的是 维护同样的内部结构,超越了两个<代码>的储存( 方法。

Note: For getting sorted properties, some time ago I followed danisupr4 implementation, but on java9 it broke.

TL;DR

The code below maintains the full functionality of Properties by overriding only store(OutputStream out, String comments) method, and is tested with all versions from java5 - java12.
I believe that filtering the output of this public method makes the implementation less fragile to future code changes in java.util.Properties class.

    class SortedStoreProperties extends Properties {
    
        @Override
        public void store(OutputStream out, String comments) throws IOException {
            Properties sortedProps = new Properties() {
                @Override
                public Set<Map.Entry<Object, Object>> entrySet() {
                    /*
                     * Using comparator to avoid the following exception on jdk >=9: 
                     * java.lang.ClassCastException: java.base/java.util.concurrent.ConcurrentHashMap$MapEntry cannot be cast to java.base/java.lang.Comparable
                     */
                    Set<Map.Entry<Object, Object>> sortedSet = new TreeSet<Map.Entry<Object, Object>>(new Comparator<Map.Entry<Object, Object>>() {
                        @Override
                        public int compare(Map.Entry<Object, Object> o1, Map.Entry<Object, Object> o2) {
                            return o1.getKey().toString().compareTo(o2.getKey().toString());
                        }
                    }
                    );
                    sortedSet.addAll(super.entrySet());
                    return sortedSet;
                }
    
                @Override
                public Set<Object> keySet() {
                    return new TreeSet<Object>(super.keySet());
                }
    
                @Override
                public synchronized Enumeration<Object> keys() {
                    return Collections.enumeration(new TreeSet<Object>(super.keySet()));
                }
    
            };
            sortedProps.putAll(this);
            sortedProps.store(out, comments);
        }
    }

注:视何人称<代码>store()而定,最好不要凌驾于现有方法之上,而是建立新的方法:例如storeSorted(<>。

NOTE:

For simplicity I override only one of the two store() methods but the same concept applies to both.