Java – unable to get unique list element

I tried to extract a unique element from the class list with the following format:

[EntityClientPlayerMP['Player989'/228,l='MpServer',x=138.16,y=68.62,z=522.96],EntityCow['Cow'/231,x=143.63,y=68.00,z=527.50]....]

These lists are usually 60-100 in size

The method I'm trying to use now is

List<Class> uniqueList = new ArrayList<Class>(new HashSet<Class>(fullList));

This will return exactly the same list, but sorted differently Any ideas?

Solution

They are sorted differently because HashSet has a "weird" sort, based on the hashcode of objects To preserve sorting, use linkedhashset

As for uniqueness, set will use equals () and hashcode (), so please ensure the correct implementation Sometimes a feasible lazy technique is to use the toString () method of the object (and call hashcode and equals on the string)