org.apache.commons.collections4.bag.HashBag Example


What is org.apache.commons.collections4.bag.HashBag class? How to use org.apache.commons.collections4.bag.HashBag class?



org.apache.commons.collections4.bag.HashBag class is a Java class offered in commons-collections4.jar that implements the org.apache.commons.collections4.Bag interface using a HashMap to provide the data storage.

A bag is a special collection which allows the same object to be added multiple times. You can also query the number of copies of a given object in the bag. and reduce the number of copies of a given object in the bag.

Here is a simple example of using org.apache.commons.collections4.bag.HashBag class:

// Copyright (c) 2016-2018
// Supports commons-collections4-4.2
// Supports commons-collections4-4.1

import org.apache.commons.collections4.Bag;
import org.apache.commons.collections4.bag.HashBag;

// Example of using the HashBagExample class
public class HashBagExample {
   public static void main(String[] args) throws Exception {
      // Create some objects
      String apple = "Apple";
      String orange = "Orange";
      String banana = "Banana";
      // Create a HashBag bag
      Bag<String> bag = new HashBag<String>();
      // Put some objects into the HashBag bag
      // Count apples, oranges and bananas
      System.out.println("# of apple: "+bag.getCount(apple));
      System.out.println("# of orange: "+bag.getCount(orange));
      System.out.println("# of banana: "+bag.getCount(banana));

      // loop through the bag
      for (String obj : bag) {
         System.out.println("Element: " + obj);

You can compile and run the above example in a command window as shown below:

   -cp C:\fyicenter\commons-collections4-4.2\commons-collections4-4.2.jar

   -cp .;C:\fyicenter\commons-collections4-4.2\commons-collections4-4.2.jar 
# of apple: 3
# of orange: 2
# of banana: 1
Element: Apple
Element: Apple
Element: Apple
Element: Banana
Element: Orange
Element: Orange


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2017-05-20, 2235🔥, 0💬