Java或第三方库中是否有一个Map保留插入顺序(类似于LinkedHashMap),该顺序还将在比较过程中检查键的顺序(equals()
和hashCode()
方法)?这样Map(a => 1, b => 2)
将不同于Map(b => 2, a => 1)
。
类似于下面,但我不想重新发明和维护方向盘:
public class EqualityStrictLinkedMap<K, V> extends ForwardingMap<K, V>
{
...
@Override
public boolean equals(Object o)
{
if (!(o instanceof Map))
return false;
Map<K, V> that = (Map<K, V>) o;
return Iterables.elementsEqual(entrySet(), that.entrySet());
}
@Override
public int hashCode()
{
int h = 1;
for (Map.Entry<K, V> entry: entrySet()) {
h = (h*31 + Objects.hashCode(entry.getKey()))*31 + Objects.hashCode(entry.getValue());
}
return h;
}
}