EasyMock - First Application

Before going into the details of the EasyMock 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
File: Stock.java

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

   public Stock(String stockId, String name, int quantity){
      this.stockId = stockId;
      this.name = 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
File: StockService.java

public interface StockService {
   public double getPrice(Stock stock);
}

Step 3: Create a class Portfolio to represent the portfolio of any client
File: Portfolio.java

import java.util.List;

public class Portfolio {
   private StockService stockService;
   private List stocks;

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

   public List getStocks() {
      return stocks;
   }

   public void setStocks(List 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 EasyMock.
File: PortfolioTester.java

import java.util.ArrayList;
import java.util.List;

import org.easymock.EasyMock;

public class PortfolioTester {
   Portfolio portfolio; 
   StockService stockService;

   public static void main(String[] args){
      PortfolioTester tester = new PortfolioTester();
      tester.setUp();
      System.out.println(tester.testMarketValue()?"pass":"fail");
   }

   public void setUp(){
      //Create a portfolio object which is to be tested  
      portfolio = new Portfolio();  
      
      //Create the mock object of stock service
      stockService = EasyMock.createMock(StockService.class);  
      
      //set the stockService to the portfolio
      portfolio.setStockService(stockService);
   }

   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); 
      
      stocks.add(googleStock);
      stocks.add(microsoftStock);

      //add stocks to the portfolio
      portfolio.setStocks(stocks);

      // mock the behavior of stock service to return the value of various stocks
      EasyMock.expect(stockService.getPrice(googleStock)).andReturn(50.00);
      EasyMock.expect(stockService.getPrice(microsoftStock)).andReturn(1000.00);  

      // activate the mock
      EasyMock.replay(stockService);  

      double marketValue = portfolio.getMarketValue();  
      return marketValue == 100500.0;
   }
}

Step 5: Verify the result
Compile the classes using javac compiler as follows:

C:\EasyMock_WORKSPACE>javac Stock.java StockService.java Portfolio.java PortfolioTester.java

Now run the PortfolioTester to see the result:

C:\EasyMock_WORKSPACE>java PortfolioTester

Verify the Output

pass