Easymock 简明教程

EasyMock - First Application

在深入了解 EasyMock Framework 之前，我们先来看看一个真实的应用。在此示例中，我们创建了 Stock Service 的模拟以获取某些股票的虚拟价格，并对名为 Portfolio 的 Java 类进行了单元测试。

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.

该过程分步如下。

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

Example

Step 1: Create a JAVA class to represent the Stock

文件：Stock.java

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.

文件：StockService.java

File: StockService.java

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

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

文件：Portfolio.java

File: Portfolio.java

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

我们通过注入 stockservice 的模拟来测试 Portfolio 类。Mock 将由 EasyMock 创建。

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

文件：PortfolioTester.java

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

使用以下 javac 编译器编译类：

Compile the classes using javac compiler as follows −

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

现在运行 PortfolioTester 以查看结果 −

Now run the PortfolioTester to see the result −

C:\EasyMock_WORKSPACE>java PortfolioTester

Output

验证输出

Verify the Output

pass