如何在 Java 中模拟静态方法？
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How to mock static method in Java?
提问by Tarek
I have a class FileGenerator, and I'm writing a test for the generateFile()method that should do the following:
我有一个 class FileGenerator，我正在为generateFile()应该执行以下操作的方法编写一个测试：
1) it should call the static method getBlockImpl(FileTypeEnum)on BlockAbstractFactory
1）它应该调用静态方法getBlockImpl(FileTypeEnum)上BlockAbstractFactory
2) it should populate variable blockListfrom the subclass method getBlocks()
2）它应该blockList从子类方法填充变量getBlocks()
3) it should call a static method createFilefrom a final helper class FileHelperpassing a String parameter
3) 它应该createFile从FileHelper传递 String 参数的最终助手类调用静态方法
4) it should call the run method of each BlockControllerin the blockList
4）它应该调用BlockControllerblockList中每个的run方法
So far, I have this empty method:
到目前为止，我有这个空方法：
public class FileGenerator {
// private fields with Getters and Setters
public void generateBlocks() {
}
}
I am using JUnit, Mockito to mock objects and I've tried using PowerMockito to mock static and final classes (which Mockito doesn't do).
我正在使用 JUnit、Mockito 来模拟对象，并且我尝试使用 PowerMockito 来模拟静态和最终类（Mockito 不这样做）。
My problem is: my first test (calling method getBlockList()from BlockAbstractFactory) is passing, even though there is no implementation in generateBlocks(). I have implemented the static method in BlockAbstractFactory(returning null, so far), to avoid Eclipse syntax errors.
我的问题是：我的第一个测试（getBlockList()从调用方法BlockAbstractFactory）正在通过，即使generateBlocks(). 我已经在BlockAbstractFactory（返回 null，到目前为止）中实现了静态方法，以避免 Eclipse 语法错误。
How can I test if the static method is called within fileGerator.generateBlocks()?
如何测试静态方法是否在内部调用fileGerator.generateBlocks()？
Here's my Test Class, so far:
到目前为止，这是我的测试课程：
@RunWith(PowerMockRunner.class)
public class testFileGenerator {
FileGenerator fileGenerator = new FileGenerator();
@Test
public void shouldCallGetBlockList() {
fileGenerator.setFileType(FileTypeEnum.SPED_FISCAL);
fileGenerator.generateBlocks();
PowerMockito.mockStatic(BlockAbstractFactory.class);
PowerMockito.verifyStatic();
BlockAbstractFactory.getBlockImpl(fileGenerator.getFileType());
}
}
回答by bas
I have no experience with PowerMock, but since you didn't get an answer yet I'm just been reading through the documentation to see if I can help you a bit on your way.
我没有使用 PowerMock 的经验，但由于您还没有得到答案，我只是在通读文档，看看我是否可以帮助您。
I found that you need to prepare PowerMock so that I knows which static methods it needs to prepare to be mocked. Like so:
我发现你需要准备 PowerMock 以便我知道它需要准备哪些静态方法来模拟。像这样：
@RunWith(PowerMockRunner.class)
@PrepareForTest(BlockAbstractFactory.class) // <<=== Like that
public class testFileGenerator {
// rest of you class
}
Hereyou can find more information.
在这里您可以找到更多信息。
Does that help?
这有帮助吗？
回答by cahen
Working example:
工作示例：
@RunWith(PowerMockRunner.class)
@PrepareForTest({ClassStaticA.class, ClassStaticB.class})
public class ClassStaticMethodsTest {
@Test
public void testMockStaticMethod() {
PowerMock.mockStatic(ClassStaticA.class);
EasyMock.expect(ClassStaticA.getMessageStaticMethod()).andReturn("mocked message");
PowerMock.replay(ClassStaticA.class);
assertEquals("mocked message", ClassStaticA.getMessageStaticMethod());
}
