Java PowerMockito.when().thenReturn(),随机UUID未返回预期值
我正在尝试测试一个Web服务方法,它连接到一个包含JCR节点的SQL Server数据库,就像我们使用JackRabbit一样 该方法如下所示:Java PowerMockito.when().thenReturn(),随机UUID未返回预期值,java,spring,junit,uuid,powermockito,Java,Spring,Junit,Uuid,Powermockito,我正在尝试测试一个Web服务方法,它连接到一个包含JCR节点的SQL Server数据库,就像我们使用JackRabbit一样 该方法如下所示: public String addDocumentByJson(String fileName, byte[] fileContent, int status, String userName, String jsonProperties) { UUID id = UUID.randomUUID(); // It does a bunc
public String addDocumentByJson(String fileName, byte[] fileContent, int status, String userName, String jsonProperties) {
UUID id = UUID.randomUUID();
// It does a bunch of operations here
return jsonResult;
}
其中jsonResult
是一个类似于此的对象:
{
"id" : "<A random UUID>"
"version" : 1
}
但是,当我测试此方法时,它给出了以下结果:
Results :
Failed tests:
testAddDocumentsByJson(com.optimissa.test.junit.TestJackRabbitService): expected:<{"id":"[1efaf3b8-ca7c-4e6f-878f-102d9a7a92d9]","version":1}> but was:<{"id":"[cfa1a8b0-be6a-46b1-90f5-d2f6d230796a]","version":1}>
从我读到(但我不明白)也许我需要从我试图测试的类中创建一个新对象?我在测试类的一开始就注入了依赖关系,我对JUnit
测试非常陌生,英语不是我的母语,但是我可以理解大部分内容,但是这个答案让我很难理解它(因为我缺乏JUnit测试方面的知识)
如何使我的JUnit
测试检索方法内部生成的相同ID(或拦截对UUID.randomUUD()
的调用以返回我的JUnit
测试内部的值)
编辑 尝试@hammerfest的答案后,进行以下更改:
UUID uuid = PowerMockito.mock(UUID.class);
mockStatic(UUID.class);
when(UUID.randomUUID()).thenReturn(uuid);
String jsonToCompare = "{\"id\":\"" + uuid + "\",\"version\":1}";
String jsonFromJRS = jackRabbitService.addDocumentByJson(nameFile, bytes, nameApp, 5, jsonproperties);
assertEquals(jsonFromJRS, jsonToCompare);
我仍然得到这个结果:
testAddDocumentsByJson(com.optimissa.test.junit.TestJackRabbitService): expected:<{"id":"[493410b3-dd0b-4b78-97bf-289f50f6e74f]","version":1}> but was:<{"id":"[00000000-0000-0000-0000-000000000000]","version":1}>
testAddDocumentsByJson(com.optimisa.test.junit.TestJackRabbitService):应为:但为:
我重新使用并修改了@hammerfest的示例,该示例在我的机器上运行
第一种情况只是模拟UUID类的静态调用,并断言SUT返回的UUID等于模拟的UUID:
import org.junit.Test;
import org.junit.runner.RunWith;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;
import java.util.UUID;
import static org.hamcrest.CoreMatchers.equalTo;
import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.assertThat;
import static org.powermock.api.mockito.PowerMockito.mockStatic;
import static org.powermock.api.mockito.PowerMockito.when;
@PrepareForTest({ UUID.class })
@RunWith(PowerMockRunner.class)
public class StaticMockTest {
@Test
public void test() {
MyClass sut = new MyClass();
UUID uuidLocal = UUID.randomUUID();
mockStatic(UUID.class);
when(UUID.randomUUID()).thenReturn(uuidLocal);
assertThat(sut.getUUID(), is(equalTo(uuidLocal)));
}
private class MyClass {
public UUID getUUID() {
return UUID.randomUUID();
}
}
}
import org.junit.Test;
import org.junit.runner.RunWith;
import org.powermock.core.classloader.annotations.PowerMockIgnore;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;
import org.powermock.modules.junit4.PowerMockRunnerDelegate;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.test.context.BootstrapWith;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.test.context.support.AnnotationConfigContextLoader;
import org.springframework.test.context.support.DefaultTestContextBootstrapper;
import java.util.UUID;
import javax.annotation.Resource;
import static org.hamcrest.CoreMatchers.equalTo;
import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.assertThat;
import static org.powermock.api.mockito.PowerMockito.mockStatic;
import static org.powermock.api.mockito.PowerMockito.when;
@PrepareForTest({ UUID.class })
@RunWith(PowerMockRunner.class)
@PowerMockRunnerDelegate(SpringRunner.class)
@BootstrapWith(DefaultTestContextBootstrapper.class)
@ContextConfiguration(classes = {StaticMockTest2.ContextConfig.class},
loader= AnnotationConfigContextLoader.class)
@PowerMockIgnore({"javax.management.*"})
public class StaticMockTest2 {
@Resource
private MyClass sut;
@Test
public void test() {
UUID uuidLocal = UUID.randomUUID();
mockStatic(UUID.class);
when(UUID.randomUUID()).thenReturn(uuidLocal);
assertThat(sut.getUUID(), is(equalTo(uuidLocal)));
}
private static class MyClass {
public UUID getUUID() {
return UUID.randomUUID();
}
}
@Configuration
public static class ContextConfig {
@Bean
public MyClass myClass() {
return new MyClass();
}
}
}
第二种情况调用Spring托管bean的方法,该方法返回模拟的UUID:
import org.junit.Test;
import org.junit.runner.RunWith;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;
import java.util.UUID;
import static org.hamcrest.CoreMatchers.equalTo;
import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.assertThat;
import static org.powermock.api.mockito.PowerMockito.mockStatic;
import static org.powermock.api.mockito.PowerMockito.when;
@PrepareForTest({ UUID.class })
@RunWith(PowerMockRunner.class)
public class StaticMockTest {
@Test
public void test() {
MyClass sut = new MyClass();
UUID uuidLocal = UUID.randomUUID();
mockStatic(UUID.class);
when(UUID.randomUUID()).thenReturn(uuidLocal);
assertThat(sut.getUUID(), is(equalTo(uuidLocal)));
}
private class MyClass {
public UUID getUUID() {
return UUID.randomUUID();
}
}
}
import org.junit.Test;
import org.junit.runner.RunWith;
import org.powermock.core.classloader.annotations.PowerMockIgnore;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;
import org.powermock.modules.junit4.PowerMockRunnerDelegate;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.test.context.BootstrapWith;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.test.context.support.AnnotationConfigContextLoader;
import org.springframework.test.context.support.DefaultTestContextBootstrapper;
import java.util.UUID;
import javax.annotation.Resource;
import static org.hamcrest.CoreMatchers.equalTo;
import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.assertThat;
import static org.powermock.api.mockito.PowerMockito.mockStatic;
import static org.powermock.api.mockito.PowerMockito.when;
@PrepareForTest({ UUID.class })
@RunWith(PowerMockRunner.class)
@PowerMockRunnerDelegate(SpringRunner.class)
@BootstrapWith(DefaultTestContextBootstrapper.class)
@ContextConfiguration(classes = {StaticMockTest2.ContextConfig.class},
loader= AnnotationConfigContextLoader.class)
@PowerMockIgnore({"javax.management.*"})
public class StaticMockTest2 {
@Resource
private MyClass sut;
@Test
public void test() {
UUID uuidLocal = UUID.randomUUID();
mockStatic(UUID.class);
when(UUID.randomUUID()).thenReturn(uuidLocal);
assertThat(sut.getUUID(), is(equalTo(uuidLocal)));
}
private static class MyClass {
public UUID getUUID() {
return UUID.randomUUID();
}
}
@Configuration
public static class ContextConfig {
@Bean
public MyClass myClass() {
return new MyClass();
}
}
}
这两个测试都在我的机器上工作,不过我建议将UUID生成重构为一个实用程序类,您可以通过Spring实例化并注入该类。然后,您可以简单地用普通的Mockito mock替换PowerMock,并避免处理此类问题:
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.test.context.support.AnnotationConfigContextLoader;
import java.util.UUID;
import javax.annotation.Resource;
import static org.hamcrest.CoreMatchers.equalTo;
import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.assertThat;
import static org.mockito.Mockito.mock;
import static org.powermock.api.mockito.PowerMockito.when;
@RunWith(SpringRunner.class)
@ContextConfiguration(classes = {MockTest3.ContextConfig.class},
loader= AnnotationConfigContextLoader.class)
public class MockTest3 {
@Resource
private Util mockUtil;
@Resource
private MyClass sut;
@Test
public void test() {
UUID uuidLocal = UUID.randomUUID();
when(mockUtil.generateUUID()).thenReturn(uuidLocal);
assertThat(sut.getUUID(), is(equalTo(uuidLocal)));
}
private static class MyClass {
private Util util;
public MyClass(Util util) {
this.util = util;
}
public UUID getUUID() {
return util.generateUUID();
}
}
private static class Util {
public UUID generateUUID() {
return UUID.randomUUID();
}
}
@Configuration
public static class ContextConfig {
@Bean
public Util mockUtil() {
return mock(Util.class);
}
@Bean
public MyClass myClass() {
return new MyClass(mockUtil());
}
}
}
如果您不想依赖Spring进行测试(以进一步加快速度),您可以自己通过构造函数注入或通过Whitebox.setInternalState(sut,“fieldName”,mockObject)注入依赖项代码>或弹簧<代码>ReflectionUtils.setField(sut,“fieldName”,mockObject)代码>
import org.junit.Test;
import org.mockito.internal.util.reflection.Whitebox;
import java.util.UUID;
import javax.annotation.Resource;
import static org.hamcrest.CoreMatchers.equalTo;
import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.assertThat;
import static org.mockito.Mockito.mock;
import static org.powermock.api.mockito.PowerMockito.when;
public class MockTest4 {
@Test
public void test() {
Util mockUtil = mock(Util.class);
MyClass sut = new MyClass(mockUtil);
// MyClass sut = new MyClass();
// Whitebox.setInternalState(sut, "util", mockUtil);
UUID uuidLocal = UUID.randomUUID();
when(mockUtil.generateUUID()).thenReturn(uuidLocal);
assertThat(sut.getUUID(), is(equalTo(uuidLocal)));
}
private class MyClass {
@Resource
private Util util;
public MyClass() {}
public MyClass(Util util) {
this.util = util;
}
public UUID getUUID() {
return util.generateUUID();
}
}
private class Util {
public UUID generateUUID() {
return UUID.randomUUID();
}
}
}
最后一个测试包含两个选项,构造函数或字段注入,您可以使用它们
由于@hammerfest的评论,我在这里添加了一个进一步的示例,展示了如果MyClass
是外部定义的,该怎么办。注意:这个例子基本上是在我阅读@ArthurZagretdinov的答案之前,他可能是这个测试的作者(正如@hammerfest在评论中指出的)。首先是独立的MyClass
实现:
import java.util.UUID;
public class MyClass {
public UUID getUUID() {
return UUID.randomUUID();
}
}
接下来,使用外部MyClass
定义的测试:
import org.junit.Test;
import org.junit.runner.RunWith;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;
import java.util.UUID;
import static org.hamcrest.CoreMatchers.equalTo;
import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.assertThat;
import static org.powermock.api.mockito.PowerMockito.mockStatic;
import static org.powermock.api.mockito.PowerMockito.when;
@PrepareForTest({ MyClass.class })
@RunWith(PowerMockRunner.class)
public class StaticMockTest3 {
@Test
public void test() {
MyClass sut = new MyClass();
final String id = "493410b3-dd0b-4b78-97bf-289f50f6e74f";
UUID uuid = UUID.fromString(id);
// UUID uuidLocal = UUID.randomUUID();
mockStatic(UUID.class);
when(UUID.randomUUID()).thenReturn(uuidLocal);
// when(UUID.randomUUID()).thenReturn(uuidLocal);
assertThat(sut.getUUID().toString(), is(equalTo(uuid.toString())));
}
}
如果您在上面的cenario中注释掉了两个注释行,您将发现由于UUID不相等,测试将失败。这意味着MyClass
的准备工作也尊重使用声明的UUID mock,因此可以用于模拟静态类。模拟系统类的常见错误是将它们添加到@PrepareForTest
,但不幸的是,无法直接模拟最终的Java系统类。但是PowerMock提供了。PowerMock通过调用PowerMock类来替换对系统类的调用。应将使用最终系统类的类添加到@PrepareForTest
我已经添加了如何模拟UUID
public class DocumentService {
public JsonDocument saveDocument(JsonDocument document){
UUID uuid = UUID.randomUUID();
document.setId(uuid.toString());
return document;
}
}
试验
您可以在中找到更多信息。@JarrodRoberson这不是dup,因为链接的问题是问“如何使用UUID进行单元测试”。在我的案例中,我明确表示,我尝试了该问题的公认答案,该答案导致我的测试失败,我问的是一个特殊的问题,而不是一般性的问题。与我的示例相比,本质上的区别似乎是,您已经将MyClass作为测试本身的一个内部类。这似乎确实有效,但我怀疑OP在现实生活环境中是否也能做到这一点。@hammerfest与其准备UUID进行测试,不如准备MyClass进行该特定情况下的测试。此外,我的答案还包含了如何完全避免PowerMock甚至Spring的方法,这对于测试IMOWell更为可取,因为它不是一个“特殊”的情况,而是一个“真实”的情况,而假设SUT是测试的一个内部类基本上改变了您正在测试的环境;不过,让我们看看这对OP.Btw来说是否可以接受。复制Arthur Zagretdinov答案的精髓(即使UUID值是相同的)而不给他任何荣誉的出色工作。@hammerfest我从github(可能是他的)示例,可以通过您发布的链接访问,在我更新我的帖子之前,我没有读到他的答案。我承认我复制了源代码并对其进行了轻微修改,我的缺点是没有链接到github示例。不过,我这篇文章的实质是有多种方法可以测试UUID(我更喜欢在可能的情况下避免使用PowerMock)。顺便说一句,@RomanVottner,如果将生成UUID提取到单独的类并提供接口,那么就没有理由使用Spring或WhiteBox类。Mockito有InjectMocks
,EasyMock有TestSubject
用于这些目的。这一个似乎有效,并且由于您是PowerMock的贡献者,我假设这是预期的解决方案。我不明白的是,你链接的2009年文章显然来自同一位作者,他随后宣布“不可能解决”,并在我链接的2015年github票证中提出了所有0解决方案。还是我误解了什么?你链接的票证是在2015年从Google Source导入GitHub的。但无论如何,它是创建和回答后,然后张贴。我认为,这是误解。正如您可以从示例中看到的,它现在起作用了。
@RunWith(PowerMockRunner.class)
@PrepareForTest(DocumentService.class)
public class DocumentServiceTest {
@Test
public void should_set_id() throws Exception {
final String id = "493410b3-dd0b-4b78-97bf-289f50f6e74f";
UUID uuid = UUID.fromString(id);
mockStatic(UUID.class);
when(UUID.randomUUID()).thenReturn(uuid);
DocumentService documentService = new DocumentService();
JsonDocument document = new JsonDocument();
documentService.saveDocument(document);
assertThat(document.getId())
.as("Id is set")
.isEqualTo(id);
}
}