我是一個單元測試與模擬對象的新手。我使用EasyMock。我試圖理解這個例子:模擬對象和接口
import java.io.IOException;
public interface ExchangeRate {
double getRate(String inputCurrency, String outputCurrency) throws IOException;
}
import java.io.IOException;
public class Currency {
private String units;
private long amount;
private int cents;
public Currency(double amount, String code) {
this.units = code;
setAmount(amount);
}
private void setAmount(double amount) {
this.amount = new Double(amount).longValue();
this.cents = (int) ((amount * 100.0) % 100);
}
public Currency toEuros(ExchangeRate converter) {
if ("EUR".equals(units)) return this;
else {
double input = amount + cents/100.0;
double rate;
try {
rate = converter.getRate(units, "EUR");
double output = input * rate;
return new Currency(output, "EUR");
} catch (IOException ex) {
return null;
}
}
}
public boolean equals(Object o) {
if (o instanceof Currency) {
Currency other = (Currency) o;
return this.units.equals(other.units)
&& this.amount == other.amount
&& this.cents == other.cents;
}
return false;
}
public String toString() {
return amount + "." + Math.abs(cents) + " " + units;
}
}
import junit.framework.TestCase;
import org.easymock.EasyMock;
import java.io.IOException;
public class CurrencyTest extends TestCase {
public void testToEuros() throws IOException {
Currency testObject = new Currency(2.50, "USD");
Currency expected = new Currency(3.75, "EUR");
ExchangeRate mock = EasyMock.createMock(ExchangeRate.class);
EasyMock.expect(mock.getRate("USD", "EUR")).andReturn(1.5);
EasyMock.replay(mock);
Currency actual = testObject.toEuros(mock);
assertEquals(expected, actual);
}
}
所以,我不知道如何使用貨幣在EXCHANGERATE方法toEuros(..)
。
rate = converter.getRate(units, "EUR");
未指定getRate(..)
方法的行爲,因爲ExchangeRate
是一個接口。
/********************************************************************************/
所以我嘗試做我自己的例子。以下是我的代碼:
/**
*Interface to access data
*/
public interface Dao {
public boolean getEntityById(int id) throws SQLException;
}
/**
*Business class do something in business layer
*/
public class Bussiness {
private Dao dao;
public Dao getDao() {
return dao;
}
public void setDao(Dao dao) {
this.dao = dao;
}
public boolean doSomeThing(int id) throws SQLException {
if(dao.getEntityById(id)) {
return true;
} else {
return false;
}
}
public static void main(String[] args) throws SQLException {
Bussiness b = new Bussiness();
b.doSomeThing(3);
}
}
package tunl;
import java.sql.SQLException;
import org.easymock.EasyMock;
import org.testng.Assert;
import org.testng.annotations.BeforeTest;
import org.testng.annotations.Test;
/**
* This is my unit Test
*/
@Test
public class MyUnitTest {
private Bussiness bussiness;
private Dao mock;
@BeforeTest
public void setUp() {
bussiness = new Bussiness();
mock = EasyMock.createMock(Dao.class);// interface not class
bussiness.setDao(mock);
}
public void testDoSomeThing() throws SQLException {
EasyMock.expect(mock.getEntityById(3)).andReturn(true);
EasyMock.replay(mock);
Assert.assertTrue(bussiness.doSomeThing(3));
}
}
因此,該單位苔絲正確運行
但是,當我想運行在業務對象主要方法:
public static void main(String[] args) throws SQLException {
Bussiness b = new Bussiness();
b.doSomeThing(3);
}
我要補充的業務構造。
public Bussiness() {
dao = new DaoImpl();
}
所以,我的業務類:
package tunl;
import java.sql.SQLException;
public class Bussiness {
private Dao dao;
public Bussiness() {
dao = new DaoImpl();
}
public Dao getDao() {
return dao;
}
public void setDao(Dao dao) {
this.dao = dao;
}
public boolean doSomeThing(int id) throws SQLException {
if(dao.getEntityById(id)) {
return true;
} else {
return false;
}
}
public static void main(String[] args) throws SQLException {
Bussiness b = new Bussiness();
b.doSomeThing(3);
}
}
而且我要實現DAO接口:
package tunl;
import java.sql.SQLException;
public class DaoImpl implements Dao {
@Override
public boolean getEntityById(int id) throws SQLException {
if(id == 3) {
System.out.println("System input 3 ");
return true;
}
System.out.println("You have to input 3 ");
return false;
}
}
在外觀設計上,你總是對所有類的創建界面,將進行測試(如DaoImpl)! 那它正確嗎?
感謝PéterTörök先生, EasyMock在CurrencyTest中指定了接口的方法。 但我仍然不明白如何貨幣使用接口的方法(不CurrencyTest)。 因爲你總是必須在EasyMock中使用接口,所以如何對業務類進行響應。 – user338027 2010-05-12 01:39:08
@tunl,看我的更新。 – 2010-05-12 11:18:28
現在,我明白了。我的弱點是我不知道如何將DaoImpl傳遞給Business。 Mock總是和Interface一起工作。 再次感謝您對我的錯誤感到抱歉。 – user338027 2010-05-12 17:33:15