Java Language
- Getting started with Java Language
- Top 10 Java Errors with Solutions
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-
Sorting a List using Comparable
or a Comparator - Creating a Comparator using comparing method
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Java Language Comparable and Comparator Sorting Map entries
Example
As of Java 8, there are default methods on the Map.Entry interface to allow sorting of map iterations.
Java SE 8
Map<String, Integer> numberOfEmployees = new HashMap<>();
numberOfEmployees.put("executives", 10);
numberOfEmployees.put("human ressources", 32);
numberOfEmployees.put("accounting", 12);
numberOfEmployees.put("IT", 100);
// Output the smallest departement in terms of number of employees
numberOfEmployees.entrySet().stream()
.sorted(Map.Entry.comparingByValue())
.limit(1)
.forEach(System.out::println); // outputs : executives=10
Of course, these can also be used outside of the stream api :
Java SE 8
List<Map.Entry<String, Integer>> entries = new ArrayList<>(numberOfEmployees.entrySet());
Collections.sort(entries, Map.Entry.comparingByValue());
