elasticsearch - 任何 java.lang.NullPointerException 时的 Mockito

Question

我有这个必须测试的方法:

    private void processRequest() {
        BulkRequest request = new BulkRequest();
        request.add(new IndexRequest("posts").id("1")
                .source(XContentType.JSON,"field", "foo"));
        request.add(new IndexRequest("posts").id("2")
                .source(XContentType.JSON,"field", "bar"));
        final BulkResponse bulkResponse = restHighLevelClient.bulk(request, RequestOptions.DEFAULT);
    }

这就是我试图从我的测试课上做的事情:

    RestHighLevelClient restHighLevelClientMock = mock(RestHighLevelClient.class);

    final String errorMessage = "error message";
    final Exception cause = new Exception("test exception");
    final boolean isFailed = true;
    final int itemID = 0;
    // define the item failure
    BulkItemResponse.Failure failure = mock(BulkItemResponse.Failure.class);
    when(failure.getCause()).thenReturn(cause);
    when(failure.getMessage()).thenReturn(errorMessage);
    // define the item level response
    BulkItemResponse itemResponse = mock(BulkItemResponse.class);
    when(itemResponse.isFailed()).thenReturn(isFailed);
    when(itemResponse.getItemId()).thenReturn(itemID);
    when(itemResponse.getFailure()).thenReturn(failure);
    when(itemResponse.getFailureMessage()).thenReturn("error message");
    List<BulkItemResponse> itemsResponses = Collections.singletonList(itemResponse);
    // define the bulk response to indicate failure
    BulkResponse response = mock(BulkResponse.class);
    when(response.iterator()).thenReturn(itemsResponses.iterator());
    when(response.hasFailures()).thenReturn(isFailed);
    // have the client return the mock response
    when(restHighLevelClientMock.bulk(any(BulkRequest.class), RequestOptions.DEFAULT)).thenReturn(response);

我收到 java.lang.NullPointerException 在这一行:

when(restHighLevelClientMock.bulk(any(BulkRequest.class), RequestOptions.DEFAULT)).thenReturn(response);

知道为什么会这样吗？谢谢

Answer 1

我也遇到了这个问题，这导致我提出了这个 github 请求:
https://github.com/elastic/elasticsearch/issues/40534
Elasticsearc 的 RestHighLevelClient 类将许多公共(public)方法标记为 final方法，使其无法模拟。
github页面中详细介绍了有关创建委托(delegate)的解决方法，虽然不太理想，但有效。
编辑:在挖掘了可能的解决方案后，我发现了这篇文章:见 https://www.baeldung.com/mockito-final .我在自己的项目中进行了尝试，并让我的测试与 junit jupiter 一起工作。
将以下内容添加到您的 src/test/resources 文件夹中:

mockito-extensions/org.mockito.plugins.MockMaker

将以下行添加到 org.mockito.plugins.MockMaker 文件:

mock-maker-inline