使用Mockito模拟Apache HTTPClient

Question

我正在尝试模拟Apache HttpClient接口，以便模拟下面提到的其中一个方法，以返回一个存根JSON对象作为响应。

HttpResponse response = defaultHttpClient.execute(postRequest); 

有人能建议如何通过一些示例代码来实现这一点吗？非常感谢您的帮助。

感谢

Answer 1

以下是我使用Mockito和Apache HttpBuilder:测试代码的步骤

测试类别：

import java.io.BufferedReader;
import java.io.IOException;
import javax.ws.rs.core.Response.Status;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.HttpClientBuilder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class StatusApiClient {
private static final Logger LOG = LoggerFactory.getLogger(StatusApiClient.class);
    private String targetUrl = "";
    private HttpClient client = null;
    HttpGet httpGet = null;
    public StatusApiClient(HttpClient client, HttpGet httpGet) {
        this.client = client;
        this.httpGet = httpGet;
    }
    public StatusApiClient(String targetUrl) {
        this.targetUrl = targetUrl;
        this.client = HttpClientBuilder.create().build();
        this.httpGet = new HttpGet(targetUrl);
    }
    public boolean getStatus() {
        BufferedReader rd = null;
        boolean status = false;
        try{
            LOG.debug("Requesting status: " + targetUrl);

            HttpResponse response = client.execute(httpGet);
            if(response.getStatusLine().getStatusCode() == Status.OK.getStatusCode()) {
                LOG.debug("Is online.");
                status = true;
            }
        } catch(Exception e) {
            LOG.error("Error getting the status", e);
        } finally {
            if (rd != null) {
                try{
                    rd.close();
                } catch (IOException ioe) {
                    LOG.error("Error while closing the Buffered Reader used for reading the status", ioe);
                }
            }   
        }
        return status;
    }
}

测试：

import java.io.IOException;
import org.apache.http.HttpResponse;
import org.apache.http.StatusLine;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.conn.HttpHostConnectException;
import org.junit.Assert;
import org.junit.Test;
import org.mockito.Mockito;
public class StatusApiClientTest extends Mockito {
    @Test
    public void should_return_true_if_the_status_api_works_properly() throws ClientProtocolException, IOException {
        //given:
        HttpClient httpClient = mock(HttpClient.class);
        HttpGet httpGet = mock(HttpGet.class);
        HttpResponse httpResponse = mock(HttpResponse.class);
        StatusLine statusLine = mock(StatusLine.class);
        //and:
        when(statusLine.getStatusCode()).thenReturn(200);
        when(httpResponse.getStatusLine()).thenReturn(statusLine);
        when(httpClient.execute(httpGet)).thenReturn(httpResponse);
        //and:
        StatusApiClient client = new StatusApiClient(httpClient, httpGet);
        //when:
        boolean status = client.getStatus();
        //then:
        Assert.assertTrue(status);
    }
    @Test
    public void should_return_false_if_status_api_do_not_respond() throws ClientProtocolException, IOException {
        //given:
        HttpClient httpClient = mock(HttpClient.class);
        HttpGet httpGet = mock(HttpGet.class);
        HttpResponse httpResponse = mock(HttpResponse.class);
        StatusLine statusLine = mock(StatusLine.class);
        //and:
        when(httpClient.execute(httpGet)).thenThrow(HttpHostConnectException.class);
        //and:
        StatusApiClient client = new StatusApiClient(httpClient, httpGet);
        //when:
        boolean status = client.getStatus();
        //then:
        Assert.assertFalse(status);
    }
}

伙计们，你们觉得我需要改进吗？（是的，我知道，评论。这是我从斯波克背景中带来的：D）

Answer 2

在单元测试类中，您需要模拟defaultHttpClient:

@Mock
private HttpClient defaultHttpClient;

然后告诉mockito（例如在@Before方法中）通过以下方式实际创建mock：

MockitoAnnotations.initMocks(YourTestClass);

然后在测试方法中定义execute()方法应该返回的内容：

when(defaultHttpClient.execute(any()/* or wahtever you want here */)).thenReturn(stubbed JSON object);

Answer 3

有一种更好的方法可以做到这一点，而不必添加PowerMock作为另一个依赖项。在这里，您只需要一个额外的构造函数，将HTTPClient作为参数和Mockito。在这个例子中，我正在创建一个自定义的健康检查（Spring Actuator），我需要模拟HTTPClient进行单元测试。

Libs:JUnit 5、Spring Boot 2.1.2和Mockito 2。

组件：

@Component
public class MyHealthCheck extends AbstractHealthIndicator {
    HttpClient httpClient;
    public MyHealthCheck() { 
        httpClient = HttpClientBuilder.create().build();
    }
    /** 
    Added another constructor to the class with an HttpClient argument.
    This one can be used for testing
    */ 
    public MyHealthCheck(HttpClient httpClient) { 
        this.httpClient = httpClient; 
    }
    /**
    Method to test 
    */ 
    @Override
    protected void doHealthCheck(Builder builder) throws Exception {
        //
        // Execute request and get status code
        HttpGet request = new HttpGet("http://www.SomeAuthEndpoint.com");
        HttpResponse response = httpClient.execute(request);
        //
        // Update builder according to status code
        int statusCode = response.getStatusLine().getStatusCode();
        if(statusCode == 200 || statusCode == 401) {
            builder.up().withDetail("Code from service", statusCode);
        } else {
            builder.unknown().withDetail("Code from service", statusCode);
        }
    }
}

测试方法：

注意，这里我们使用Mockito.any（HttpGet.class）

private static HttpClient httpClient;
private static HttpResponse httpResponse;
private static StatusLine statusLine;
@BeforeAll
public static void init() {
    //
    // Given
    httpClient = Mockito.mock(HttpClient.class);
    httpResponse = Mockito.mock(HttpResponse.class);
    statusLine = Mockito.mock(StatusLine.class);
}

@Test
public void doHealthCheck_endReturns401_shouldReturnUp() throws Exception {
    //
    // When
    when(statusLine.getStatusCode()).thenReturn(401);
    when(httpResponse.getStatusLine()).thenReturn(statusLine);
    when(httpClient.execute(Mockito.any(HttpGet.class))).thenReturn(httpResponse);
    //
    // Then
    MyHealthCheck myHealthCheck = new MyHealthCheck(httpClient);
    Health.Builder builder = new Health.Builder();
    myHealthCheck.doHealthCheck(builder);
    Status status = builder.build().getStatus();
    Assertions.assertTrue(Status.UP == status);
}

Answer 4

您可以查看HttpClientMock，我为内部项目编写了它，但后来决定开源。它允许您用流利的API定义mock行为，并在以后验证许多调用。示例：

HttpClientMock httpClientMock = new 
HttpClientMock("http://localhost:8080");
httpClientMock.onGet("/login?user=john").doReturnJSON("{permission:1}");
httpClientMock.verify().get("/login?user=john").called();

Answer 5

您可以使用PowerMockito轻松实现这一点，它还可以轻松模拟最终/静态方法、私有方法和匿名类。以下是用于模拟http请求的示例代码。JSON_STRING_DATA是您想要从execute方法获得的任何字符串。

PowerMockito.mockStatic(DefaultHttpClient.class);
    HttpClient defaultHttpClientMocked =  PowerMockito.mock(DefaultHttpClient.class);        
    PowerMockito.when(defaultHttpClientMocked.execute(Mockito.any(HttpPost.class))).thenReturn(createMockedHTTPResponse(JSON_STRING_DATA));