I’m trying to convert a List<String> to a TreeMap<Long, CustomClass> The key is the same as the list items but just parsed to Long, the value is just a call to new CustomClass(). How can I achieve this using lambda functions? the above code errors out, with the following error, Answer For example:
Tag: treemap
How to match equals() and hashCode in streams?
I have a stream where I am aggregating some data like this: The problem is that by adding this comparator I am braking the contract between hashCode() and equals() and at the end I have duplicate keys: Has anyone some ideas how can I fix this? Or is there a way to sort the final object ( Map<String, Map<String, Map<EventType,
putting value in Treemap understanding issues
I was running through a leetcode problem. and found a solution in the discussion section problem- https://leetcode.com/problems/stock-price-fluctuation/ solution- but I do not understand the following parts. if someone could explain that would be great Answer To solve the problem you need to know how often the stock is traded for a particular price. An example: it was traded at timestamp
Comparing the contents of two Treemaps
I have two TreeMaps that I want to compare. I currently have it written down like below but I feel like this could be written more efficiently. I tried looking in to comparators, but I don’t think that’s something I can use for my use-case. The maps are Treemaps because the key must be case-insensitive. Thanks in advance Answer If
How treemap handles case of putting key on same index?
I tried out following code: public static void main (String[] args) throws java.lang.Exception { // sorting based on number of dots Map map =new TreeMap((o1, o2) -&…
Why do I get an error when entering child classes to a TreeMap defined for their parent? [closed]
In my program I have an abstract class TelephoneEntry which holds a TelephoneNumber(it implements Comparable) and an addres, then I have child classes Person and Company that extend the …
How to write custom comparator in java?
I want to store key-value pairs in TreeMap and sort the entries based on the value of key as per the following logic: “type” (case insensitive) key should be at first. the key start with &…
Does using an Iterator over a TreeMap in Java interfere with the order of keys?
I want to know that if using an Iterator over a TreeMap in Java interfere with the order of keys?
Find element position in a Java TreeMap
I am working with a TreeMap of Strings TreeMap<String, String>, and using it to implement a Dictionay of words. I then have a collection of files, and would like to create a representation of each file in the vector space (space of words) defined by the dictionary. Each file should have a vector representing it with following properties: vector should