Apache DefaultHttpClient invocation results in "java.lang.RuntimeException: Stub!"

Question

I'm dipping my toes into Android development. I have a project that will interface with a RESTful resource and I'm trying to figure out how to do a basic GET with params over HTTP. From everything I've read, the consensus seems to be favoring HTTPClient over HttpURLConnection.

I've written a wrapper class with a method that takes care of instantiating the key object to make a request using HTTPClient:

public String get() {  
    String responseString = null;

    HttpClient client = new DefaultHttpClient();
    HttpGet get = new HttpGet();
    try {
        get.setURI(new URI(this.baseURL()));
    } catch (URISyntaxException e1) {
        e1.printStackTrace();
    }

    HttpResponse response;

    try {
        response = client.execute(get);
        responseString = readResponse(response.getEntity());

        if(response != null) {
            System.out.println(responseString);
        }
    } catch(ClientProtocolException e) {
        e.printStackTrace();
    } catch(IOException e) {
        e.printStackTrace();
    }

    return responseString;

}

The line HttpClient client = new DefaultHttpClient(); throws the following exception:

java.lang.RuntimeException: Stub!
at org.apache.http.impl.client.AbstractHttpClient.<init>(AbstractHttpClient.java:5)
at org.apache.http.impl.client.DefaultHttpClient.<init>(DefaultHttpClient.java:7)
at org.rcindustries.appmap.RestClient.get(RestClient.java:54)
at org.rcindustries.appmap.test.functional.RestClientTest.shouldReturnSomeJSon(RestClientTest.java:26)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:28)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:76)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184)
at org.junit.runners.ParentRunner.run(ParentRunner.java:236)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:49)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)

Every example I've seen for HttpClient uses a similar structure to do GETs and POSTs. Is the Apache Commons library bundled with the Android SDK significantly different that the standard lib?

Answer 1

I think this is Android's way of telling you that you cannot run that unit test on that platform. Unit tests that involve interacting with the Android platform (e.g. the network in this case) need to be run on an actual Android device or a functioning Android emulator.

(They cannot be run in the context of regular Eclipse. In the early days, you needed Android plugins for Eclipse. These days (since 2013) you should be using Android Studio which build on Intellij.)

Apparently, what you were actually doing was running the unit tests against the stub classes provided by the Android SDK. This cannot ever work.