java - Jersey - 如何模拟服务

Question

我正在使用“Jersey 测试框架”对我的网络服务进行单元测试。

这是我的资源类:

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;

// The Java class will be hosted at the URI path "/helloworld" 

@Path("/helloworld") 
public class class HelloWorldResource {

    private SomeService service;

    @GET 
    @Produces("text/plain")
    public String getClichedMessage() {
        // Return some cliched textual content
        String responseFromSomeService = service.getSomething();
        return responseFromSomeService;
    }
}

如何在单元测试中模拟 SomeService？

Answer 1

请参阅下面的更新:您不需要 Factory

---

如果您使用的是 Jersey 2，一种解决方案是使用 Custom Injection and Lifecycle Management功能(带有 HK2 - 与 Jersey dist 一起提供)。当然，还需要一个 Mocking 框架。我将使用 Mockito。

首先用模拟实例创建一个工厂:

public static interface GreetingService {
    public String getGreeting(String name);
}

public static class MockGreetingServiceFactory 
                                     implements Factory<GreetingService> {
    @Override
    public GreetingService provide() {
        final GreetingService mockedService
                = Mockito.mock(GreetingService.class);
        Mockito.when(mockedService.getGreeting(Mockito.anyString()))
                .thenAnswer(new Answer<String>() {
                    @Override
                    public String answer(InvocationOnMock invocation) 
                                                      throws Throwable {
                        String name = (String)invocation.getArguments()[0];
                        return "Hello " + name;
                    }

                });
        return mockedService;
    }

    @Override
    public void dispose(GreetingService t) {}
}

然后使用AbstractBinder将工厂绑定(bind)到接口(interface)/服务类，并注册绑定(bind)器。 (上面的链接中都有描述):

@Override
public Application configure() {
    AbstractBinder binder = new AbstractBinder() {
        @Override
        protected void configure() {
            bindFactory(MockGreetingServiceFactory.class)
                               .to(GreetingService.class);
        }
    };
    ResourceConfig config = new ResourceConfig(GreetingResource.class);
    config.register(binder);
    return config;
}

看似很多，其实只是一种选择。我不太熟悉测试框架，或者它是否具有用于注入(inject)的模拟功能。

这是完整的测试:

import javax.inject.Inject;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.QueryParam;
import javax.ws.rs.client.Client;
import javax.ws.rs.client.ClientBuilder;
import javax.ws.rs.core.Application;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;
import org.glassfish.hk2.api.Factory;
import org.glassfish.hk2.utilities.binding.AbstractBinder;
import org.glassfish.jersey.server.ResourceConfig;
import org.glassfish.jersey.test.JerseyTest;
import org.junit.Assert;
import org.junit.Test;
import org.mockito.Mockito;
import org.mockito.invocation.InvocationOnMock;
import org.mockito.stubbing.Answer;

public class ServiceMockingTest extends JerseyTest {

    @Path("/greeting")
    public static class GreetingResource {

        @Inject
        private GreetingService greetingService;

        @GET
        @Produces(MediaType.TEXT_PLAIN)
        public String getGreeting(@QueryParam("name") String name) {
            return greetingService.getGreeting(name);
        }
    }

    public static interface GreetingService {
        public String getGreeting(String name);
    }
    
    public static class MockGreetingServiceFactory 
                                  implements Factory<GreetingService> {
        @Override
        public GreetingService provide() {
            final GreetingService mockedService
                    = Mockito.mock(GreetingService.class);
            Mockito.when(mockedService.getGreeting(Mockito.anyString()))
                    .thenAnswer(new Answer<String>() {
                        @Override
                        public String answer(InvocationOnMock invocation) 
                                                       throws Throwable {
                            String name = (String)invocation.getArguments()[0];
                            return "Hello " + name;
                        }

                    });
            return mockedService;
        }

        @Override
        public void dispose(GreetingService t) {}
    }

    @Override
    public Application configure() {
        AbstractBinder binder = new AbstractBinder() {
            @Override
            protected void configure() {
                bindFactory(MockGreetingServiceFactory.class)
                        .to(GreetingService.class);
            }
        };
        ResourceConfig config = new ResourceConfig(GreetingResource.class);
        config.register(binder);
        return config;
    }
    
    @Test
    public void testMockedGreetingService() {
        Client client = ClientBuilder.newClient();
        Response response = client.target("http://localhost:9998/greeting")
                .queryParam("name", "peeskillet")
                .request(MediaType.TEXT_PLAIN).get();
        Assert.assertEquals(200, response.getStatus());
        
        String msg = response.readEntity(String.class);
        Assert.assertEquals("Hello peeskillet", msg);
        System.out.println("Message: " + msg);
        
        response.close();
        client.close();
       
    }
}

此测试的依赖项:

<dependency>
    <groupId>org.glassfish.jersey.test-framework.providers</groupId>
    <artifactId>jersey-test-framework-provider-grizzly2</artifactId>
    <version>2.13</version>
</dependency>
<dependency>
    <groupId>org.mockito</groupId>
    <artifactId>mockito-all</artifactId>
    <version>1.9.0</version>
</dependency>

---

更新

所以在大多数情况下，你真的不需要Factory。您可以简单地将模拟实例与其契约(Contract)绑定(bind):

@Mock
private Service service;

@Override
public ResourceConfig configure() {
    MockitoAnnotations.initMocks(this);
    return new ResourceConfig()
        .register(MyResource.class)
        .register(new AbstractBinder() {
            @Override
            protected configure() {
                bind(service).to(Service.class);
            }
        });
}

@Test
public void test() {
    when(service.getSomething()).thenReturn("Something");
    // test
}

简单多了!