mirror of
https://github.com/Estom/notes.git
synced 2026-02-04 19:13:24 +08:00
259 lines
7.2 KiB
Markdown
259 lines
7.2 KiB
Markdown
用EasyMock生成模拟对象进行单元测试 ｜ Testing with EasyMock
|
||
===
|
||
当项目达到一定规模时会根据业务或功能进行模块化，这时研发团队在协作时会碰到一个问题：如何让相互依赖的各模块并行开发？常用的办法是：各模块之间有清晰的边界，模块之间的交互通过接口。在设计阶段定义模块的接口，然后各个模块开发时遵循接口的定义进行实现和调用。
|
||
|
||
OK，并行开发的问题解决了。但不同的模块因其复杂度和工作量不同，进度不一致。当研发同学完成所负责的模块时，但依赖的模块还没有完成开发，不好进行测试。
|
||
这里就讲如何用EasyMock生成Mock Object模拟所依赖模块的接口来完成单元测试。
|
||
|
||
|
||
|
||
预备
|
||
---
|
||
* easymock-3.2.jar
|
||
* easymockclassextension-3.2.jar
|
||
* cglib-2.2.2.jar
|
||
* objenesis-1.2.jar
|
||
* asm-3.1.jar
|
||
* asm-commons-3.1.jar
|
||
* asm-util-3.1.jar
|
||
* gson-2.2.4.jar // *用于处理JSON*
|
||
|
||
注：上面的jar文件均可从[MAVEN仓库](http://mvnrepository.com)下载。
|
||
|
||
|
||
使用EasyMock的五部曲
|
||
---
|
||
1、引入EasyMock。
|
||
```java
|
||
import static org.easymock.EasyMock.*;
|
||
```
|
||
2、创建Mock Object。
|
||
```java
|
||
mock = createMock(InterfaceOrClass.class);
|
||
```
|
||
3、设置Mock Object的行为和预期结果。
|
||
```java
|
||
mock.doSomeThing();
|
||
expectLastCall().times(1); // 至少要调用一次doSomeThing方法
|
||
```
|
||
或者
|
||
```java
|
||
// 模拟抛出异常
|
||
expect(mock.getSomeThing(anyString()))
|
||
.andThrow(new IOException("单元测试特意抛的异常"));
|
||
|
||
// 模拟返回指定的数据
|
||
expect(mock.getSomeThing(anyString()))
|
||
.andReturn("abcd");
|
||
```
|
||
4、设置Mock Object变成可用状态。
|
||
```java
|
||
replay(mock);
|
||
```
|
||
5、运行单元测试代码（会调用到Mock Object的方法）。
|
||
```java
|
||
// 如果是校验调用次数就要用到verify方法
|
||
verify(mock);
|
||
```
|
||
|
||
实践
|
||
---
|
||
### 业务代码
|
||
[源码下载](https://raw.githubusercontent.com/aofeng/JavaDemo/master/src/cn/aofeng/demo/easymock/UserService.java)
|
||
```java
|
||
package cn.aofeng.demo.easymock;
|
||
|
||
import java.io.IOException;
|
||
import java.lang.reflect.Type;
|
||
import java.util.Map;
|
||
|
||
import org.apache.log4j.Logger;
|
||
|
||
import com.google.gson.Gson;
|
||
import com.google.gson.reflect.TypeToken;
|
||
|
||
import cn.aofeng.demo.jetty.HttpGet;
|
||
|
||
/**
|
||
* 用户相关服务。如：获取用户昵称。
|
||
*
|
||
* @author <a href="mailto:aofengblog@163.com">聂勇</a>
|
||
*/
|
||
public class UserService {
|
||
|
||
private static Logger _logger = Logger.getLogger(UserService.class);
|
||
|
||
private HttpGet _httpGet = new HttpGet();
|
||
|
||
/**
|
||
* 根据用户的账号ID获取昵称。
|
||
*
|
||
* @param accountId 用户的账号ID
|
||
* @return 如果账号ID有效且请求成功，返回昵称；否则返回默认的昵称"用户xxx"。
|
||
*/
|
||
public String getNickname(String accountId) {
|
||
String targetUrl = "http://192.168.56.102:8080/user?method=getNickname&accountId="+accountId;
|
||
String response = null;
|
||
try {
|
||
response = _httpGet.getSomeThing(targetUrl);
|
||
} catch (IOException e) {
|
||
_logger.error("获取用户昵称时出错,账号ID:"+accountId, e);
|
||
}
|
||
|
||
if (null != response) {
|
||
// 响应数据结构示例：{"nickname":"张三"}
|
||
Type type = new TypeToken<Map<String, String>>() {}.getType();
|
||
Map<String, String> data = new Gson().fromJson(response, type);
|
||
if (null != data && data.containsKey("nickname")) {
|
||
return data.get("nickname");
|
||
}
|
||
}
|
||
|
||
return "用户"+accountId;
|
||
}
|
||
|
||
protected void setHttpGet(HttpGet httpGet) {
|
||
this._httpGet = httpGet;
|
||
}
|
||
|
||
}
|
||
```
|
||
|
||
[源码下载](https://raw.githubusercontent.com/aofeng/JavaDemo/master/src/cn/aofeng/demo/jetty/HttpGet.java)
|
||
```java
|
||
package cn.aofeng.demo.jetty;
|
||
|
||
import java.io.ByteArrayOutputStream;
|
||
import java.io.IOException;
|
||
import java.io.InputStream;
|
||
import java.net.HttpURLConnection;
|
||
import java.net.URL;
|
||
|
||
import org.apache.commons.io.IOUtils;
|
||
|
||
/**
|
||
* HTTP GET请求。
|
||
*
|
||
* @author <a href="mailto:aofengblog@163.com">聂勇</a>
|
||
*/
|
||
public class HttpGet {
|
||
|
||
public String getSomeThing(String urlStr) throws IOException {
|
||
URL url = new URL(urlStr);
|
||
HttpURLConnection urlConn = (HttpURLConnection) url.openConnection();
|
||
urlConn.setConnectTimeout(3000);
|
||
urlConn.setRequestMethod("GET");
|
||
urlConn.connect();
|
||
|
||
InputStream ins = null;
|
||
try {
|
||
if (200 == urlConn.getResponseCode()) {
|
||
ins = urlConn.getInputStream();
|
||
ByteArrayOutputStream outs = new ByteArrayOutputStream(1024);
|
||
IOUtils.copy(ins, outs);
|
||
return outs.toString("UTF-8");
|
||
}
|
||
} catch (IOException e) {
|
||
throw e;
|
||
} finally {
|
||
IOUtils.closeQuietly(ins);
|
||
}
|
||
|
||
return null;
|
||
}
|
||
|
||
}
|
||
```
|
||
|
||
### 单元测试代码
|
||
[源码下载](https://raw.githubusercontent.com/aofeng/JavaDemo/master/src/cn/aofeng/demo/easymock/UserServiceTest.java)
|
||
```java
|
||
package cn.aofeng.demo.easymock;
|
||
|
||
import static org.junit.Assert.*;
|
||
|
||
import java.io.IOException;
|
||
|
||
import static org.easymock.EasyMock.*;
|
||
import org.junit.After;
|
||
import org.junit.Before;
|
||
import org.junit.Test;
|
||
|
||
import cn.aofeng.demo.jetty.HttpGet;
|
||
|
||
/**
|
||
* {@link UserService}的单元测试用例。
|
||
*
|
||
* @author <a href="mailto:aofengblog@163.com">聂勇</a>
|
||
*/
|
||
public class UserServiceTest {
|
||
|
||
private HttpGet _mock = createMock(HttpGet.class);
|
||
|
||
@Before
|
||
public void setUp() throws Exception {
|
||
}
|
||
|
||
@After
|
||
public void tearDown() throws Exception {
|
||
reset(_mock);
|
||
}
|
||
|
||
|
||
/**
|
||
* 测试用例：获取用户昵称 <br/>
|
||
* 前置条件：
|
||
* <pre>
|
||
* 网络请求时发生IO异常
|
||
* </pre>
|
||
*
|
||
* 测试结果：
|
||
* <pre>
|
||
* 返回默认的用户昵称"用户xxx"
|
||
* </pre>
|
||
*/
|
||
@Test
|
||
public void testGetNickname4OccursIOError() throws IOException {
|
||
// 设置Mock
|
||
expect(_mock.getSomeThing(anyString()))
|
||
.andThrow(new IOException("单元测试特意抛的异常"));
|
||
replay(_mock);
|
||
|
||
UserService us = new UserService();
|
||
us.setHttpGet(_mock);
|
||
String nickname = us.getNickname("123456");
|
||
verify(_mock); // 校验mock
|
||
assertEquals("用户123456", nickname); // 检查返回值
|
||
}
|
||
|
||
/**
|
||
* 测试用例：获取用户昵称 <br/>
|
||
* 前置条件：
|
||
* <pre>
|
||
* 1、网络请求成功。
|
||
* 2、响应状态码为200且响应内容符合接口定义（{\"nickname\":\"张三\"}）。
|
||
* </pre>
|
||
*
|
||
* 测试结果：
|
||
* <pre>
|
||
* 返回"张三"
|
||
* </pre>
|
||
*/
|
||
@Test
|
||
public void testGetNickname4Success() throws IOException {
|
||
// 设置Mock
|
||
_mock.getSomeThing(anyString());
|
||
expectLastCall().andReturn("{\"nickname\":\"张三\"}");
|
||
expectLastCall().times(1);
|
||
replay(_mock);
|
||
|
||
UserService us = new UserService();
|
||
us.setHttpGet(_mock);
|
||
String nickname = us.getNickname("123456");
|
||
verify(_mock); // 校验方法的调用次数
|
||
assertEquals("张三", nickname); // 校验返回值
|
||
}
|
||
|
||
}
|
||
```
|