我想知道如何为Volley框架创建单元测试。模拟请求和响应,以便我可以创建不需要工作的Web服务和网络访问的单元测试。
我已经在谷歌上搜索过了,但是没有找到有关该框架的太多信息。
我想知道如何为Volley框架创建单元测试。模拟请求和响应,以便我可以创建不需要工作的Web服务和网络访问的单元测试。
我已经在谷歌上搜索过了,但是没有找到有关该框架的太多信息。
我实现了HttpStack的一个子类,名为FakeHttpStack,它从位于res/raw目录下的本地文件中加载伪造的响应体。我这样做是为了开发目的,即在服务端准备好之前,我可以为新API开发一些东西,但你可以从这里学到一些东西(例如重写HttpStack#performRequest和createEntity)。
/**
* Fake {@link HttpStack} that returns the fake content using resource file in res/raw.
*/
class FakeHttpStack implements HttpStack {
private static final String DEFAULT_STRING_RESPONSE = "Hello";
private static final String DEFAULT_JSON_RESPONSE = " {\"a\":1,\"b\":2,\"c\":3}";
private static final String URL_PREFIX = "http://example.com/";
private static final String LOGGER_TAG = "STACK_OVER_FLOW";
private static final int SIMULATED_DELAY_MS = 500;
private final Context context;
FakeHttpStack(Context context) {
this.context = context;
}
@Override
public HttpResponse performRequest(Request<?> request, Map<String, String> stringStringMap)
throws IOException, AuthFailureError {
try {
Thread.sleep(SIMULATED_DELAY_MS);
} catch (InterruptedException e) {
}
HttpResponse response
= new BasicHttpResponse(new BasicStatusLine(HttpVersion.HTTP_1_1, 200, "OK"));
List<Header> headers = defaultHeaders();
response.setHeaders(headers.toArray(new Header[0]));
response.setLocale(Locale.JAPAN);
response.setEntity(createEntity(request));
return response;
}
private List<Header> defaultHeaders() {
DateFormat dateFormat = new SimpleDateFormat("EEE, dd mmm yyyy HH:mm:ss zzz");
return Lists.<Header>newArrayList(
new BasicHeader("Date", dateFormat.format(new Date())),
new BasicHeader("Server",
/* Data below is header info of my server */
"Apache/1.3.42 (Unix) mod_ssl/2.8.31 OpenSSL/0.9.8e")
);
}
/**
* returns the fake content using resource file in res/raw. fake_res_foo.txt is used for
* request to http://example.com/foo
*/
private HttpEntity createEntity(Request request) throws UnsupportedEncodingException {
String resourceName = constructFakeResponseFileName(request);
int resourceId = context.getResources().getIdentifier(
resourceName, "raw", context.getApplicationContext().getPackageName());
if (resourceId == 0) {
Log.w(LOGGER_TAG, "No fake file named " + resourceName
+ " found. default fake response should be used.");
} else {
InputStream stream = context.getResources().openRawResource(resourceId);
try {
String string = CharStreams.toString(new InputStreamReader(stream, Charsets.UTF_8));
return new StringEntity(string);
} catch (IOException e) {
Log.e(LOGGER_TAG, "error reading " + resourceName, e);
}
}
// Return default value since no fake file exists for given URL.
if (request instanceof StringRequest) {
return new StringEntity(DEFAULT_STRING_RESPONSE);
}
return new StringEntity(DEFAULT_JSON_RESPONSE);
}
/**
* Map request URL to fake file name
*/
private String constructFakeResponseFileName(Request request) {
String reqUrl = request.getUrl();
String apiName = reqUrl.substring(URL_PREFIX.length());
return "fake_res_" + apiName;
}
}
要使用FakeHttpStack,您只需要将其传递给您的RequestQueue。我也重写了RequestQueue。
public class FakeRequestQueue extends RequestQueue {
public FakeRequestQueue(Context context) {
super(new NoCache(), new BasicNetwork(new FakeHttpStack(context)));
}
}
这种方法的优点是,它不需要对您的代码进行太多更改。您只需要在测试时将RequestQueue更换为FakeRequestQueue即可。因此,它可以用于验收测试或系统测试。
另一方面,对于单元测试来说,可能有更紧凑的方式。例如,您可以将您的Request.Listener子类实现为单独的类,以便可以轻松测试onResponse方法。我建议您在关于您想要测试的内容或放置一些代码片段时提供更多细节。
请看 volley 测试 文件夹,您可以在那里找到示例。
MockCache.java
MockHttpClient.java
MockHttpStack.java
MockHttpURLConnection.java
MockNetwork.java
MockRequest.java
MockResponseDelivery.java
这里是@Dmytro提到的当前Volley的MockHttpStack的副本
。
package com.android.volley.mock;
import com.android.volley.AuthFailureError;
import com.android.volley.Request;
import com.android.volley.toolbox.HttpStack;
import org.apache.http.HttpResponse;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
public class MockHttpStack implements HttpStack {
private HttpResponse mResponseToReturn;
private IOException mExceptionToThrow;
private String mLastUrl;
private Map<String, String> mLastHeaders;
private byte[] mLastPostBody;
public String getLastUrl() {
return mLastUrl;
}
public Map<String, String> getLastHeaders() {
return mLastHeaders;
}
public byte[] getLastPostBody() {
return mLastPostBody;
}
public void setResponseToReturn(HttpResponse response) {
mResponseToReturn = response;
}
public void setExceptionToThrow(IOException exception) {
mExceptionToThrow = exception;
}
@Override
public HttpResponse performRequest(Request<?> request, Map<String, String> additionalHeaders)
throws IOException, AuthFailureError {
if (mExceptionToThrow != null) {
throw mExceptionToThrow;
}
mLastUrl = request.getUrl();
mLastHeaders = new HashMap<String, String>();
if (request.getHeaders() != null) {
mLastHeaders.putAll(request.getHeaders());
}
if (additionalHeaders != null) {
mLastHeaders.putAll(additionalHeaders);
}
try {
mLastPostBody = request.getBody();
} catch (AuthFailureError e) {
mLastPostBody = null;
}
return mResponseToReturn;
}
}
我不完全确定我理解你想做什么,但如果我理解了,那么easymock(一个允许创建模拟类的库,您可以调用并接收预定响应)将帮助您很多。一个叫Lars Vogel的人在这个主题上有一篇不错的文章,我以前使用它时发现它很有用。