Powermockito在存根時拋出OutOfMemory異常FileOutputStream

Question

我不確定爲什麼會發生這種情況，但是當我運行測試代碼時，出現OutOfMemoryException異常。

測試：

@RunWith(PowerMockRunner.class) 
@PrepareForTest(UploadBulkRefundAction.class) 
public class UploadBulkRefundActionTest { 

    @Mock 
    private File file; 
    @Mock 
    private BulkRefundsForm bulkRefundsForm; 
    @Mock 
    private FormFile spreadsheetFile; 
    @Mock 
    private InputStream is; 
    @Mock 
    private FileOutputStream fileOutputStream; 

    @Before 
    public void setup() throws Exception { 
     PowerMockito.mockStatic(File.class); 
     PowerMockito.mockStatic(FileOutputStream.class); 
     PowerMockito.mockStatic(IOUtils.class); 
     PowerMockito.whenNew(FileOutputStream.class).withArguments(file).thenReturn(fileOutputStream); 
    } 

    @Test 
    public void shouldStoreFileIntoTempFile() throws Exception { 
     when(File.createTempFile("tomcat-","bulkrefunds.xlsx")).thenReturn(file); 
     when(bulkRefundsForm.getSpreadsheetFile()).thenReturn(spreadsheetFile); 
     when(spreadsheetFile.getInputStream()).thenReturn(is); 
     UploadBulkRefundAction action=new UploadBulkRefundAction(); 

     action.execute(null, bulkRefundsForm, null, null); 

     verify(spreadsheetFile).getInputStream(); 
     verifyNew(FileOutputStream.class).withArguments(file); 

     verifyStatic(); 
     File.createTempFile("tomcat-", "bulkrefunds.xlsx"); 

     verifyStatic(); 
     IOUtils.copy(is, fileOutputStream); 
    } 

} 

類在測試：

public class UploadBulkRefundAction extends MossoAction { 
    @Override 
public ActionForward execute(ActionMapping mapping, ActionForm f, HttpServletRequest request, HttpServletResponse response) throws  Exception { 
     BulkRefundsForm bulkRefundsForm=(BulkRefundsForm)f; 
     File tempFile = storeExcelSheetInATempFile(bulkRefundsForm); 
     return null; 
    } 

    private File storeExcelSheetInATempFile(BulkRefundsForm bulkRefundsForm) throws IOException { 
     InputStream inputStream=null; 
     FileOutputStream outputStream=null; 
     try{ 
      File tempFile = File.createTempFile("tomcat-", "bulkrefunds.xlsx"); 
      inputStream = bulkRefundsForm.getSpreadsheetFile().getInputStream(); 
      outputStream = new FileOutputStream(tempFile); 
      IOUtils.copy(inputStream, outputStream); 
      return tempFile; 
     }finally{ 
      IOUtils.closeQuietly(inputStream); 
      IOUtils.closeQuietly(outputStream); 
     } 
    } 
} 

Answer 1

的source code for IOUtils.copy包括一個循環，如果你InputStream無法從它的read()方法返回值 '-1'，這將永遠不會終止。

我猜測你的模擬默認返回'0'的方法返回類型爲int，所以你的測試代碼進入一個無限循環，無限地將4k大小的字節數組寫入OutputStream。