Question

您好我有一个方法，它将URL作为输入并确定它是否可访问。下面是代码：

public static boolean isUrlAccessible(final String urlToValidate) throws WAGNetworkException {
        URL url = null;
        HttpURLConnection huc = null;
        int responseCode = -1;
        try {
            url = new URL(urlToValidate);
            huc = (HttpURLConnection) url.openConnection();
            huc.setRequestMethod("HEAD");
            huc.connect();
            responseCode = huc.getResponseCode();
        } catch (final UnknownHostException e) {
            throw new WAGNetworkException(WAGConstants.INTERNET_CONNECTION_EXCEPTION);
        } catch (IOException e) {
            throw new WAGNetworkException(WAGConstants.INVALID_URL_EXCEPTION);
        } finally {
            if (huc != null) {
                huc.disconnect();
            }
        }
        return responseCode == 200;
    }

我想使用PowerMockito对isUrlAccessible（）方法进行单元测试。我觉得我需要使用whenNew()来模拟URL的创建，并且调用when url.openConnection()时，返回另一个模拟HttpURLConnection对象。但我不确定如何实现这个？我是在正确的轨道上吗？任何人都可以帮我实现这个吗？

Answer 1

找到解决方案。首先模拟URL类，然后模拟HttpURLConnection，当调用url.openconnection（）时，返回这个模拟的HttpURLConnection对象，最后将其响应代码设置为200.继承代码：

@Test
    public void function() throws Exception{
        RuleEngineUtil r = new RuleEngineUtil();
        URL u = PowerMockito.mock(URL.class);
        String url = "http://www.sdsgle.com";
        PowerMockito.whenNew(URL.class).withArguments(url).thenReturn(u);
        HttpURLConnection huc = PowerMockito.mock(HttpURLConnection.class);
        PowerMockito.when(u.openConnection()).thenReturn(huc);
        PowerMockito.when(huc.getResponseCode()).thenReturn(200);
        assertTrue(r.isUrlAccessible(url));

    }

Answer 2

您可以使用

模拟新的Url实例

whenNew(URL.class)..

确保从新呼叫时返回先前创建的模拟对象。

URL mockUrl = Mockito.mock(URL.class);
whenNew(URL.class).....thenReturn(mockUrl );

然后，您可以根据需要向模拟添加行为。

Answer 3

URL是最终课程。要模拟最终课程，我们可以将PowerMockito与Junit结合使用。为了模拟最终类，我们需要使用@RunWith（PowerMockRunner.class）和@PrepareForTest（{URL.class}）

注释测试类。


@RunWith(PowerMockRunner.class) 
@PrepareForTest({ URL.class })
public class Test {
    @Test
    public void test() throws Exception {
        URL url = PowerMockito.mock(URL.class);
        HttpURLConnection huc = Mockito.mock(HttpURLConnection.class);
        PowerMockito.when(url.openConnection()).thenReturn(huc);
        assertTrue(url.openConnection() instanceof HttpURLConnection);
    }
}

但是在 PowerMockito.when（url.openConnection（））。thenReturn（huc）; 行中，抛出以下错误：

java.lang.AbstractMethodError
    at java.net.URL.openConnection(URL.java:971)
    at java_net_URL$openConnection.call(Unknown Source)

为了消除此错误，我们可以如下所示修改Test类：

@RunWith(PowerMockRunner.class) 
@PrepareForTest({ URL.class })
public class Test {
    @Test
    public void test() throws Exception {

        public class UrlWrapper {

            URL url;

            public UrlWrapper(String spec) throws MalformedURLException {
                url = new URL(spec);
            }

            public URLConnection openConnection() throws IOException {
                return url.openConnection();
            }
        }

        UrlWrapper url = Mockito.mock(UrlWrapper.class);
        HttpURLConnection huc = Mockito.mock(HttpURLConnection.class);
        PowerMockito.when(url.openConnection()).thenReturn(huc);
        assertTrue(url.openConnection() instanceof HttpURLConnection);
    }
}

访问：https://programmingproblemsandsolutions.blogspot.com/2019/04/abstractmethoderror-is-thrown-on.html

Answer 4

为了通过mockito库模拟java.net.URL类，您需要执行以下步骤：

在src / tests / resources目录中创建一个名为“ mockito-extensions”的目录。
在文件夹中名为org.mockito.plugins.MockMaker的文本文件中创建文本，并将mock-maker-inline文本放入文件中。
您可以像下面这样模拟类：

代码：

package myproject;

import org.junit.Test;

import java.net.HttpURLConnection;
import java.net.URL;
import static org.junit.Assert.*;
import static org.mockito.Mockito.*;

public class Test {
    @Test
    public void test() throws Exception {
        URL url = mock(URL.class);
        HttpURLConnection huc = mock(HttpURLConnection.class);
        when(url.openConnection()).thenReturn(huc);
        assertTrue(url.openConnection() instanceof HttpURLConnection);
    }
}

Answer 5

使用JMockit模拟API要简单得多（甚至没有模拟也要简单）：

import java.io.*;
import java.net.*;
import org.junit.*;
import static org.junit.Assert.*;
import mockit.*;

public final class ExampleURLTest {
   public static final class ClassUnderTest {
      public static boolean isUrlAccessible(String urlToValidate) throws IOException {
         HttpURLConnection huc = null;
         int responseCode;

         try {
            URL url = new URL(urlToValidate);
            huc = (HttpURLConnection) url.openConnection();
            huc.setRequestMethod("HEAD");
            huc.connect();
            responseCode = huc.getResponseCode();
         }
         finally {
            if (huc != null) {
               huc.disconnect();
            }
         }

         return responseCode == 200;
      }
   }

   // Proper tests, no unnecessary mocking ///////////////////////////////////////

   @Test
   public void checkAccessibleUrl() throws Exception {
      boolean accessible = ClassUnderTest.isUrlAccessible("http://google.com");

      assertTrue(accessible);
   }

   @Test(expected = UnknownHostException.class)
   public void checkInaccessibleUrl() throws Exception {
      ClassUnderTest.isUrlAccessible("http://inaccessible12345.com");
   }

   @Test
   public void checkUrlWhichReturnsUnexpectedResponseCode(
      @Mocked URL anyURL, @Mocked HttpURLConnection mockConn
   ) throws Exception {
      new Expectations() {{ mockConn.getResponseCode(); result = -1; }};

      boolean accessible = ClassUnderTest.isUrlAccessible("http://invalidResource.com");

      assertFalse(accessible);
   }

   // Lame tests with unnecessary mocking ////////////////////////////////////////

   @Test
   public void checkAccessibleUrl_withUnnecessaryMocking(
      @Mocked URL anyURL, @Mocked HttpURLConnection mockConn
   ) throws Exception {
      new Expectations() {{ mockConn.getResponseCode(); result = 200; }};

      boolean accessible = ClassUnderTest.isUrlAccessible("http://google.com");

      assertTrue(accessible);
   }

   @Test(expected = UnknownHostException.class)
   public void checkInaccessibleUrl_withUnnecessaryMocking(
      @Mocked URL anyURL, @Mocked HttpURLConnection mockConn
   ) throws Exception {
      new Expectations() {{ mockConn.connect(); result = new UnknownHostException(); }};

      ClassUnderTest.isUrlAccessible("http://inaccessible12345.com");
   }
}

（在JDK 8和9上已通过JMockit 1.47验证）

Answer 6

尽管该线程有一些好的建议，但是如果您中的任何一个对使用这些第三方库不感兴趣的话，这里是一个快速的解决方案。

public class MockHttpURLConnection extends HttpURLConnection {
    private int responseCode;
    private URL url;
    private InputStream inputStream;


    public MockHttpURLConnection(URL u){
        super(null);
        this.url=u;
    }
    @Override
    public int getResponseCode() {
        return responseCode;
    }


    public void setResponseCode(int responseCode) {
        this.responseCode = responseCode;
    }

    @Override
    public URL getURL() {
        return url;
    }

    public void setUrl(URL url) {
        this.url = url;
    }

    @Override
    public InputStream getInputStream() {
        return inputStream;
    }

    public void setInputStream(InputStream inputStream) {
        this.inputStream = inputStream;
    }

    @Override
    public void disconnect() {

    }

    @Override
    public boolean usingProxy() {
        return false;
    }

    @Override
    public void connect() throws IOException {

    }
}

而且，这是设置所需行为的方式

   MockHttpURLConnection httpURLConnection=new MockHttpURLConnection(new URL("my_fancy_url"));
        InputStream stream=new ByteArrayInputStream(json_response.getBytes());
        httpURLConnection.setInputStream(stream);
        httpURLConnection.setResponseCode(200);

注意：它仅模拟HttpUrlConnection中的3种方法，如果您使用更多方法，则需要确保它们也是模拟的。

如何模拟URL连接

6 个答案: