Joining multiple ALL Filters about nitrite-java

[anidotnet]

There is a reason it was not allowed. ALL filter selects every elements in the collection. Now take these into consideration:

filter1 = Filters.ALL;
filter2 = Filters.eq(...);

collection.find(Filters.and(filter1, filter2));

Here the result is basically same as

collection.find(filter2);

Again when you use these filters in OR operation

filter1 = Filters.ALL;
filter2 = Filters.eq(...);

collection.find(Filters.or(filter1, filter2));

the result will be same as

collection.find(filter1);

which is equal to all the elements in the collection.

So if we allow null/ALL filter, it will negate the effect of other filters rendering the AND/OR operation useless. This will confuse most of the users, because it will be hard to find the cause, unless you restrict null filters in AND and OR operation.