问题描述
您好，我正在开发一个项目并使用 PrintWriter 类来打开和写入文件.但是当我编写相同的测试用例时，它会出现以下错误在第 153 行
Hi I am working on a project and using PrintWriter class for opening and writing in the file. But when I am writing the test case for same it gives following error at Line 153
Wanted but not invoked:
mockPrintWriter.println("ID url1
");
-> at x.y.z.verify(ProcessImageDataTest.java:153)
Actually, there were zero interactions with this mock.
代码:(使用 Lombok 库)
Code: (Uses Lombok Library)
ProcessImageData.java
ProcessImageData.java
@Setter
@RequiredArgsConstructor
public class ProcessImageData implements T {
private final File newImageDataTextFile;
@Override
public void execute() {
LineIterator inputFileIterator = null;
try {
File filteredImageDataTextFile = new File(filteredImageDataTextFilepath);
PrintWriter writer = new PrintWriter(newImageDataTextFile);
inputFileIterator = FileUtils.lineIterator(filteredImageDataTextFile, StandardCharsets.UTF_8.displayName());
while (inputFileIterator.hasNext()) {
if(someCondition)
**Line51** writer.println(imageDataFileLine);
//FileUtils.writeStringToFile(newImageDataTextFile, imageDataFileLine + NEWLINE, true);
}
}
} catch (Exception e) {
} finally {
LineIterator.closeQuietly(inputFileIterator);
**LINE63** writer.close();
}
}
ProcessImageDataTest.java
ProcessImageDataTest.java
@RunWith(PowerMockRunner.class)
@PrepareForTest({ ProcessImageData.class, FileUtils.class, Printwriter.class })
public class ProcessImageDataTest {
private ProcessImageData processImageData;
private static final String FILTERED_IMAGE_DATA_TEXT_FILE_PATH = "filteredFilepath";
private File FILTEREDFILE = new File(FILTERED_PATH);
private static final File IMAGE__FILE = new File("imageFilePath");
private LineIterator lineIterator;
@Mock
private PrintWriter mockPrintWriter;
@Before
public void init() throws Exception {
MockitoAnnotations.initMocks(this);
processImageData = new ProcessImageData(Palettes_file, FILTERED_PATH, IMAGE_FILE);
PowerMockito.mockStatic(FileUtils.class);
PowerMockito.whenNew(PrintWriter.class).withArguments(IMAGE_FILE).thenReturn(mockPrintWriter);
PowerMockito.when(FileUtils.lineIterator(FILTERED_FILE, StandardCharsets.UTF_8.displayName())).thenReturn(lineIterator);
PowerMockito.when(lineIterator.hasNext()).thenReturn(true, true, false);
}
@Test
public void testTaskWhenIDInDBAndStale() throws IOException {
PowerMockito.when(lineIterator.nextLine()).thenReturn(ID2 + SPACE + URL1, ID1 + SPACE + URL2);
processImageData.execute();
List<String> exepctedFileContentOutput = Arrays.asList(ID2 + SPACE + URL1 + NEWLINE);
verify(exepctedFileContentOutput, 1, 1);
}
@Test
public void testTaskWhenIDNotInDB() throws IOException {
PowerMockito.when(lineIterator.nextLine()).thenReturn(ID2 + SPACE + URL1, ID3 + SPACE + URL2);
processImageData.execute();
List<String> exepctedFileContentOutput = Arrays.asList(ID3 + SPACE + URL2 + NEWLINE);
verify(exepctedFileContentOutput, 1, 1);
}
private void verify(List<String> exepctedFileContentOutput, int fileWriteTimes, int fileReadTimes) throws IOException {
for (String line : exepctedFileContentOutput){
**Line153** Mockito.verify(mockPrintWriter, Mockito.times(fileWriteTimes)).print(line);
}
PowerMockito.verifyStatic(Mockito.times(fileReadTimes));
FileUtils.lineIterator(FILTERED_IMAGE_DATA_TEXT_FILE, StandardCharsets.UTF_8.displayName());
}
}
我也在模拟 PrintWriter 的新运算符，使用 bean 进行注入.我在做什么错?我被卡住了很长时间并且没有收到错误?任何帮助表示赞赏.
I am mocking a new operator for PrintWriter also, injecting using beans. What is the mistake I am doing?? I am stuck on it from long time and not getting the error?
Any help is appreciated.
更新:
我做了下面建议的更改并更新了代码，但现在我得到了错误:
I did changes suggested below and updated the code, but now I get the error:
Wanted but not invoked: mockPrintWriter.print("ASIN2 url1 "); ->
at softlines.ctl.ruleExecutor.tasks.ProcessImageDataTest.verify(ProcessImageDataTest.java:153)
However, there were other interactions with this mock: -> at softlines.ctl.ruleExecutor.tasks.ProcessImageData.execute(ProcessImageData.java:51) ->
at softlines.ctl.ruleExecutor.tasks.ProcessImageData.execute(ProcessImageData.java:51) ->
at softlines.ctl.ruleExecutor.tasks.ProcessImageData.execute(ProcessImageData.java:58) –
推荐答案
我在你的测试中发现了 3 个问题:
I see 3 issues in your test:
- 您不要尝试模拟 正确的构造函数，实际上在
execute方法中，您创建的PrintWriter仅使用File类型的一个参数，而您尝试模拟 具有 2 个参数的构造函数 一个File类型和另一个类型字符串.
- You don't try to mock the correct constructor, indeed in the method
execute, you create yourPrintWriterwith only one argument of typeFilewhile you try to mock the constructor with 2 arguments one of typeFileand the other one of typeString.
所以代码应该是:
PowerMockito.whenNew(PrintWriter.class)
.withArguments(IMAGE_FILE)
.thenReturn(mockPrintWriter);
为了能够模拟构造函数，您需要准备创建实例的类，在这种情况下为
ProcessImageData，因此您需要添加ProcessImageData.class在注解@PrepareForTest中.(我不确定那里是否需要ProcessImageDataTest.class)
To be able to mock a constructor you need to prepare the class creating the instance which is
ProcessImageDatain this case, so you need to addProcessImageData.classin the annotation@PrepareForTest. (I'm not sureProcessImageDataTest.classis needed there)
lineIterator 字段应使用 @Mock 进行注释.
The field lineIterator should be annotated with @Mock.
您应该直接验证 println 无需换行，而不是用新行验证 print，这样更不容易出错.
Instead of verifying print with a new line, you should verify directly println without new line it is much less error prone.
<小时>
我简化了你的代码来展示这个想法.
I simplified your code to show the idea.
假设 ProcessImageData 是:
public class ProcessImageData {
private final File newImageDataTextFile;
public ProcessImageData(final File newImageDataTextFile) {
this.newImageDataTextFile = newImageDataTextFile;
}
public void execute() throws Exception{
try (PrintWriter writer = new PrintWriter(newImageDataTextFile)) {
LineIterator inputFileIterator = FileUtils.lineIterator(
newImageDataTextFile, StandardCharsets.UTF_8.displayName()
);
while (inputFileIterator.hasNext()) {
writer.println(inputFileIterator.nextLine());
}
}
}
}
我的单元测试将是:
@RunWith(PowerMockRunner.class)
@PrepareForTest({ProcessImageData.class, FileUtils.class})
public class ProcessImageDataTest {
private File file = new File("imageFilePath");
private ProcessImageData processImageData;
@Mock
private PrintWriter mockPrintWriter;
@Mock
private LineIterator lineIterator;
@Before
public void init() throws Exception {
MockitoAnnotations.initMocks(this);
processImageData = new ProcessImageData(file);
PowerMockito.whenNew(PrintWriter.class)
.withArguments(file)
.thenReturn(mockPrintWriter);
PowerMockito.mockStatic(FileUtils.class);
PowerMockito.when(
FileUtils.lineIterator(file, StandardCharsets.UTF_8.displayName())
).thenReturn(lineIterator);
PowerMockito.when(lineIterator.hasNext()).thenReturn(true, true, false);
}
@Test
public void testExecute() throws Exception {
PowerMockito.when(lineIterator.nextLine()).thenReturn("Foo", "Bar");
processImageData.execute();
Mockito.verify(mockPrintWriter, Mockito.times(1)).println("Foo");
Mockito.verify(mockPrintWriter, Mockito.times(1)).println("Bar");
}
}
更多详情请参考如何模拟新对象的构造.
For more details please refer to How to mock construction of new objects.
如何在 writer.close 的单元测试中添加验证?
how can I add verification in unit test for writer.close?
一种方法是通过将下一行添加到单元测试中来简单地检查 close() 是否被调用:
One way could be to simply check that close() at be called once by adding the next line to your unit test:
Mockito.verify(mockPrintWriter, Mockito.times(1)).close();
这篇关于通缉但不调用:Mockito PrintWriter的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持跟版网！