如何模拟Kafka记录元数据

Question

尝试使用Mockito为下面的代码编写单元测试，但我遇到了错误使用方法的异常。结果不为空，已验证，也进入循环。

if(Result!=null) {
   result.getRecordMetadata().topic()
}

这是我所写的：

@Mock
private SendResult<String, data> sendResultData;

RecordMetadata recordMetadata = new RecordMetadata(new TopicPartition("topic", 0), 0, 0, 1234567890L, 1234567890L, 1024, 1024);

SendResult<String, Data> result = new SendResult<String, Data>(producerRecord, recordMetadata);

when(recordMetadata.topic()).thenReturn("topic");

when(sendResultData.getRecordMetadata()).thenReturn(recordMetadata);

例外情况：

org.mockito.exceptions.misusing.MissingMethodInvocationException:
when() requires an argument which has to be 'a method call on a mock'.
For example:
when(mock.getArticles()).thenReturn(articles);

Also, this error might show up because:

you stub either of: final/private/equals()/hashCode() methods.
Those methods cannot be stubbed/verified.
Mocking methods declared on non-public parent classes is not supported.

inside when() you don't call method on mock but on some other object.

at XXXXX.test(Test.java:172)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)

Answer 1

在示例中，我没有看到您在任何地方模拟recordMetadata。您不能模拟不是模拟或被监视的对象的方法。

您应该提供一个带有注释的mock：

@Mock
private RecordMetadata recordMetadata;

或者干脆：

RecordMetadata recordMetadata = Mockito.mock(RecordMetadata.class);

此外，@mock注释应为@mock