Mockito - First Application

Before going into the details of the Mockito Framework, let's see an application in action. In this example, we've created a mock of Stock Service to get the dummy price of some stocks and unit tested a java class named Portfolio.

The process is discussed below in a step-by-step manner.

Step 1 − Create a JAVA class to represent the Stock


public class Stock {
   private String stockId;
   private String name;
   private int quantity;

   public Stock(String stockId, String name, int quantity){
      this.stockId = stockId; = name;
      this.quantity = quantity;

   public String getStockId() {
      return stockId;

   public void setStockId(String stockId) {
      this.stockId = stockId;

   public int getQuantity() {
      return quantity;

   public String getTicker() {
      return name;

Step 2 − Create an interface StockService to get the price of a stock


public interface StockService {

   public double getPrice(Stock stock);


Step 3 − Create a class Portfolio to represent the portfolio of any client


import java.util.List;

public class Portfolio {
   private StockService stockService;
   private List<Stock> stocks;

   public StockService getStockService() {
      return stockService;
   public void setStockService(StockService stockService) {
      this.stockService = stockService;

   public List<Stock> getStocks() {
      return stocks;

   public void setStocks(List<Stock> stocks) {
      this.stocks = stocks;

   public double getMarketValue(){
      double marketValue = 0.0;
      for(Stock stock:stocks){
         marketValue += stockService.getPrice(stock) * stock.getQuantity();
      return marketValue;

Step 4 − Test the Portfolio class

Let's test the Portfolio class, by injecting in it a mock of stockservice. Mock will be created by Mockito.


import java.util.ArrayList;
import java.util.List;
import static org.mockito.Mockito.*;

public class PortfolioTester {
   Portfolio portfolio;
   StockService stockService;
   public static void main(String[] args){
      PortfolioTester tester = new PortfolioTester();
   public void setUp(){
      //Create a portfolio object which is to be tested
      portfolio = new Portfolio();
      //Create the mock object of stock service
      stockService = mock(StockService.class);
      //set the stockService to the portfolio
   public boolean testMarketValue(){
      //Creates a list of stocks to be added to the portfolio
      List<Stock> stocks = new ArrayList<Stock>();
      Stock googleStock = new Stock("1","Google", 10);
      Stock microsoftStock = new Stock("2","Microsoft",100);

      //add stocks to the portfolio

      //mock the behavior of stock service to return the value of various stocks
      double marketValue = portfolio.getMarketValue();
      return marketValue == 100500.0;

Step 5 − Verify the result

Compile the classes using javac compiler as follows −


Now run the PortfolioTester to see the result −

C:\Mockito_WORKSPACE>java PortfolioTester

Verify the Output