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 Liststocks; 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