How to sort list of objects in java with examples
We could achieve list of objects sorting in java by using sort() method which is available under Collections class as well as by using Comparable and Comparator interfaces. Comparable and Comparator are two interfaces in java used to sort list of objects. These interfaces are available under java.util package along with Collections class and other classes and interfaces. Comparable interface contains the method of public int compareTo(Object obj) Comparator interface contains the method of public int compare(Object obj1, Object obj2) The compare() and compareTo() methods will return negative integer(-1), or zero(0) or positive integer(1). When the first obj1 is less than obj2 method will return negative integer. When obj1 is equals to obj2 will return zero and when obj1 is grater than obj2 it will return positive integer. If it's objects are stored in any Collection classes like ArrayList, HashSet in Array and that time we need to use compare(