第三次上机内容

单元测试阶段Mock Object的用法使用的开发工具：Eclipse、JUnit、eclemma和EasyMock实际系统可能会有复杂的体系结构，例如某些类会使用底层基础类提供的功能或服务，这些被使用的类称为合作者。

当对这种复杂类进行单元测试时，实例化这些合作者通常不合理，例如：合作者类还未实现，无法提供相关功能。

但目前又需要进行单元测试，一种解决方案是采用模仿对象（Mock Object）技术。

例如实现了Purchase类，该类需要调用DBAccess类的getPriceFromDB（）方法。

目前需要对Purchase类进行测试，但DBAccess类可能还尚未实现，可以采用Mock Object技术（即MockDBAccess类）。

如图1所示实例，假设要测试Purchase类，但Purchase类调用的DBAccess类并未实现，可以派生出一个MockDBAccess类。

图1：类图相关类的代码如下：Purchase类：public class Purchase {public double getTotalPrice(DBAccess dbAccess){return dbAccess.getPriceFromDB();}}DBAccess类：public class DBAccess {public double getPriceFromDB(){//假设还未实现完整double price = 180.0;return price;}}实际的测试代码：PurchaseWithRealDBAccessTest类import static org.junit.Assert.*;import org.junit.Test;public class PurchaseWithRealDBAccessTest {@Testpublic void test() {Purchase purchase = new Purchase();DBAccess dbAccess = new DBAccess();assertEquals(180.0, purchase.getTotalPrice(dbAccess),00001);}}采用Mock Object方法MockDBAccess类：public class MockDBAccess extends DBAccess {public double getPriceFromDB(){double price = 180.0;return price;}}修改相应的测试代码：PurchaseWithMockDBAccess类import static org.junit.Assert.*;import org.junit.Test;public class PurchaseWithMockDBAccess {@Testpublic void test() {Purchase purchase = new Purchase();MockDBAccess mockDBAccess = new MockDBAccess();assertEquals(180.0, purchase.getTotalPrice(mockDBAccess),0.00001);}}实验内容：设计一个ATM系统:代码目录如下所示其中：类ATMService（提供了取款、存款、转账和查询功能）：public class ATMService {private IDataConnection dconn;public ATMService(IDataConnection dc){dconn = dc;}/**** 取款操作* @param cardNo* @param amount*/public void withdraw(String cardNo, int amount){//to be added}/**** 存款操作* @param cardNo* @param amount*/public void deposit(String cardNo, int amount){// to be added}/***** 转账操作* @param fromCardNo* @param toCardNo* @param amount*/public void transfer(String fromCardNo, String toCardNo, int amount){ // to be added}/***** 查询操作*/public int inquiry(String cardNo){// to be added}}账户信息类AccountInfopublic class AccountInfo {private String cardNo;private String password;private int balance;public AccountInfo(String c, String p, int b){cardNo=c;password = p;balance = b;}public String getCardNo() {return cardNo;}public void setCardNo(String cardNo) {this.cardNo = cardNo;}public String getPassword() {return password;}public void setPassword(String password) {this.password = password;}public int getBalance() {return balance;}public void setBalance(int balance) {this.balance = balance;}}接口：IDataConnectionpublic interface IDataConnection {public AccountInfo getAccount(String id);public void updateAccount(AccountInfo account);public void addAccount(AccountInfo account);}采用Mock Object实现MockDataConnectionimport java.util.HashMap;public class MockDataConnection implements IDataConnection { private HashMap<String,AccountInfo> mdb;public MockDataConnection(){mdb = new HashMap<String,AccountInfo>();AccountInfo a = new AccountInfo("1","111111",300);AccountInfo b = new AccountInfo("2","222222",1000);mdb.put(a.getCardNo(), a);mdb.put(b.getCardNo(), b);}@Overridepublic AccountInfo getAccount(String id) {// TODO Auto-generated method stubreturn mdb.get(id);}@Overridepublic void updateAccount(AccountInfo account) {// TODO Auto-generated method stubaddAccount(account);}@Overridepublic void addAccount(AccountInfo account) {// TODO Auto-generated method stubmdb.put(account.getCardNo(), account);}}设计测试用例对A TM类中的所有方法进行系统测试。

测试类是TestA TMServiceimport static org.junit.Assert.*;import org.junit.Test;public class TestATMService {private IDataConnection mdc = new MockDataConnection();private ATMService atm = new ATMService(mdc);@Testpublic void testWithdraw() {atm.withdraw("1", 20);AccountInfo a = mdc.getAccount("1");assertEquals(280,a.getBalance());}@Testpublic void testDeposit(){atm.deposit("1",20);AccountInfo a = mdc.getAccount("1");assertEquals(320,a.getBalance());}@Testpublic void testTransfer(){atm.transfer("2", "1", 200);AccountInfo a = mdc.getAccount("1");AccountInfo b = mdc.getAccount("2");assertEquals(500,a.getBalance());assertEquals(300,b.getBalance());}@Testpublic void testInquiry(){assertEquals(500,atm.inquiry("2"));}}作业要求:1、将ATMService类中一些方法实现完成2、利用TestATMService单元测试用例来测试实现的方法，同时利用代码覆盖工具EclEmma对代码覆盖率进行分析。

3、学习easymock的用法下载网址：/（将easymock-3.1.jar包含到项目内）一个参考学习资料：/blog/829340在另外写一个测试类TestA TMServiceWithEMock：并仿照transfer功能的写法，将其他功能补充完整：testWithdraw、testDeposit、testInquiry。