Java Merge Map Of Lists

First, we need to combine all maps into a unified stream. List result = map.values ().stream ().flatmap (list::stream).collect (collectors.tolist ()); The following iterates over the entries of mapadded by calling foreach (action) where the action consumes the key and value of each entry.

The syntax of method is as follows. The following iterates over the entries of mapadded by calling foreach (action) where the action consumes the key and value of each entry. Otherwise, it replaces the value with the results of the given remapping function.

For each entry, we call merge (key, value, remappingfunction) on.

However, given that our maps contains a same key with different values, the above merge. Tomap (function keymapper, function valuemapper) now find a simple example. If you're actually getting your map s within a list, simply iterate over it and use putall () as shown above for each map. Public static collection cartesianproduct ( collection destination, list<<strong>list</strong>> source ) { collection product = new linkedlist<> ();