Mockito - 第一個應用程式

在深入瞭解 Mockito 框架的細節之前，我們先來看一個實際的應用程式。在此示例中，我們建立了 Stock Service 的模擬，以獲取某些股票的虛擬價格，並對名為 Portfolio 的 Java 類進行了單元測試。

以下分步驟介紹了該過程。

步驟 1 − 建立一個 JAVA 類來表示股票

檔案：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;
   }
}

步驟 2 − 建立一個介面 StockService 來獲取股票價格

檔案：StockService.java

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

步驟 3 − 建立類 Portfolio 來表示任何客戶的投資組合

檔案：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;
   }
}

步驟 4 − 測試 Portfolio 類

讓我們測試 Portfolio 類，透過注入一個 stocks 的模擬。模擬將由 Mockito 建立。

檔案：PortfolioTester.java

package com.tutorialspoint.mock;

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();
      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 = mock(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
      when(stockService.getPrice(googleStock)).thenReturn(50.00);
      when(stockService.getPrice(microsoftStock)).thenReturn(1000.00);		

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

步驟 5 − 驗證結果

使用 javac 編譯器透過以下命令編譯類：

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

現在執行 PortfolioTester 以檢視結果−

C:\Mockito_WORKSPACE>java PortfolioTester

驗證輸出

pass