Mockito thenReturn 不工作，returns Null

Question

我正在尝试模拟 RestTemplate.exchange 方法。主要class如下：

import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.RequestEntity;
import org.springframework.http.ResponseEntity;
import org.springframework.web.client.RestTemplate;

public class JsonPlaceHolder {
    
    private RestTemplate restTemplate;

    public JsonPlaceHolder(RestTemplate restTemplate) {
        super();
        this.restTemplate = restTemplate;
    }

    
    public Post fetchPostEntity() {
        HttpHeaders headers = new HttpHeaders();
        Post reqPost = new Post();
        HttpEntity<Post> requestEntity = new HttpEntity<Post>(reqPost, headers);
        ResponseEntity<Post> respEntity = restTemplate.exchange("https://jsonplaceholder.typicode.com/posts/1",
                HttpMethod.GET, requestEntity, Post.class);
        System.out.println(respEntity);     
        return reqPost;     
    }
}

postclass是：

public class Post {
    private String userId;
    private String id;
    private String title;
    private String body;
    
    // Getters and Setters

    @Override
    public String toString() {
        return "Post [userId=" + userId + ", id=" + id + ", title=" + title + ", body=" + body + "]";
    }
    
}

为了测试上面的内容class我有下面的代码

@RunWith(MockitoJUnitRunner.class)
public class JsonPlaceHolderTest {
    
    @Mock
    private RestTemplate mockedRestTemplate;
    private String post1Uri = "https://jsonplaceholder.typicode.com/posts/1";

    
    
    @Test
    public void restTemplateExchange() {
        JsonPlaceHolder jsonPlaceHolder = new JsonPlaceHolder(mockedRestTemplate);
        
        Post fakePost = new Post();
        fakePost.setBody("BODY");
        fakePost.setId("44");
        fakePost.setUserId("USERID");
        fakePost.setTitle("TITLE");
        
        HttpHeaders headers = new HttpHeaders();
        
        Post reqPost = new Post();
        HttpEntity<Post> requestEntity = new HttpEntity<Post>(reqPost, headers);
        
        
        ResponseEntity<Post> fakeRespEntity = new ResponseEntity<Post>(fakePost, HttpStatus.OK);
        
        
        when(mockedRestTemplate.exchange(post1Uri, HttpMethod.GET, requestEntity, Post.class)).thenReturn(fakeRespEntity);
        
        Post respPost = jsonPlaceHolder.fetchPostEntity();
        
        System.out.println(respPost);
    }

}

输出为：

null
Post [userId=null, id=null, title=null, body=null]

为什么 when().thenReturn() 不能与 RestTemplate.exchange() 一起使用。我用 RestTemplate.getForEntity() 尝试了类似的事情，并且有效。

Answer 1

RequestEntity 与您用于模拟的实例不同，因为它是在 fetchPostEntity 函数中创建的。你可以试试：

when(mockedRestTemplate.exchange(eq(post1Uri), eq(HttpMethod.GET), any(HttpEntity.class), any()).thenReturn(fakeRespEntity);

有关参数匹配器的详细信息，请参阅 https://javadoc.io/doc/org.mockito/mockito-core/latest/org/mockito/ArgumentMatchers.html。

Mockito thenReturn 不工作，returns Null

Mockito thenReturn not working, returns Null

java

testing

spring

mockito