title: java.lang.RuntimeException: Unable to capture screenshot while using spoon
body: <p>I am trying to capture a screenshot during a JUnit esspresso test. Android wasn't reconizing the activity before so I added the <code>private Activity activity</code>. That enabled the code to be run. However, now I get the following stack trace when it attempts to take a screenshot:</p>
  
  <pre><code>java.lang.RuntimeException: Unable to capture screenshot.
  at com.squareup.spoon.Spoon.screenshot(Spoon.java:87)
  at com.squareup.spoon.Spoon.screenshot(Spoon.java:60)
  at com.lifehealth.irma.test.Screenshotscripts.screencap2.Screencap1(screencap2.java:122)
  at java.lang.reflect.Method.invoke(Native Method)
  at java.lang.reflect.Method.invoke(Method.java:372)
  at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
  at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
  at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
  at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
  at android.support.test.internal.statement.UiThreadStatement.evaluate(UiThreadStatement.java:55)
  at android.support.test.rule.ActivityTestRule$ActivityStatement.evaluate(ActivityTestRule.java:270)
  at org.junit.rules.RunRules.evaluate(RunRules.java:20)
  at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
  at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
  at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
  at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
  at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
  at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
  at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
  at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
  at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
  at org.junit.runners.Suite.runChild(Suite.java:128)
  at org.junit.runners.Suite.runChild(Suite.java:27)
  at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
  at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
  at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
  at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
  at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
  at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
  at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
  at org.junit.runner.JUnitCore.run(JUnitCore.java:115)
  at android.support.test.internal.runner.TestExecutor.execute(TestExecutor.java:59)
  at android.support.test.runner.AndroidJUnitRunner.onStart(AndroidJUnitRunner.java:262)
  at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:1853)
  Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.Context android.app.Activity.getApplicationContext()' on a null object reference
  at com.squareup.spoon.Spoon.screenshot(Spoon.java:78)
  ... 33 more
  </code></pre>
  
  <p>The following is my code:</p>
  
  <pre><code>import android.app.Activity;
  import android.support.test.espresso.action.ViewActions;
  import android.support.test.espresso.matcher.ViewMatchers;
  import android.support.test.rule.ActivityTestRule;
  import android.support.test.runner.AndroidJUnit4;
  import android.test.ActivityInstrumentationTestCase2;
  import android.test.suitebuilder.annotation.LargeTest;
  
  import com.lifehealth.MainActivity;
  import com.lifehealth.irma.R;
  import com.squareup.spoon.Spoon;
  
  import org.junit.Before;
  import org.junit.Rule;
  import org.junit.Test;
  import org.junit.runner.RunWith;
  
  import static android.support.test.espresso.Espresso.onView;
  import static android.support.test.espresso.action.ViewActions.click;
  import static android.support.test.espresso.action.ViewActions.closeSoftKeyboard;
  import static android.support.test.espresso.action.ViewActions.doubleClick;
  import static android.support.test.espresso.action.ViewActions.swipeUp;
  import static android.support.test.espresso.action.ViewActions.typeText;
  import static android.support.test.espresso.matcher.ViewMatchers.withId;
  import static android.support.test.espresso.matcher.ViewMatchers.withText;
  
  
  //hamcrest
  
  /**
   *
   * Basic tests showcasing simple view matchers and actions like {@link ViewMatchers#withId},
   * {@link ViewActions#click} and {@link ViewActions#typeText}.
   * &lt;p&gt;
   * Note that there is no need to tell Espresso that a view is in a different {@link Activity}.
   */
  
  @RunWith(AndroidJUnit4.class)
  @LargeTest
  // Name of the activity + Test
  public class screencap2  {
      //Strings to be typed into tests declaration
      public static final String STRING_TO_BE_TYPED = "Test1233";
      public static final String loginID = "LIFEHEALTH";
      public static final String Device = "TestDevice";
  
  
  
  
          /**
           * A JUnit {@link Rule @Rule} to launch your activity under test. This is a replacement
           * for {@link ActivityInstrumentationTestCase2}.
           * &lt;p&gt;
           * Rules are interceptors which are executed for each test method and will run before
           * any of your setup code in the {@link Before @Before} method.
           * &lt;p&gt;
           * {@link ActivityTestRule} will create and launch of the activity for you and also expose
           * the activity under test. To get a reference to the activity you can use
           * the {@link ActivityTestRule#getActivity()} method.
           */
          //Rule that tells the system which screen to start/boot up on this is telling the device to start from the main menu screen.
          @Rule
          public ActivityTestRule&lt;MainActivity&gt; mActivityRule = new ActivityTestRule&lt;&gt;(
                  MainActivity.class);
      private Activity activity;
  
  
      //@Test must be there to start a test if this is missing it will not run the test
          @Test
          public void Screencap1  () { /* passes*/
              //Enters login
              onView(withId(R.id.editOid)) /*editTextUserInput*/
                      .perform(typeText(loginID), closeSoftKeyboard());
              // then click next
              onView(withId(R.id.btn_next)).perform(click());
              // "Clicks the settings
              onView(withId(R.id.btnSettings)).perform(click());
              //Clicks Device Settings.
              onView(withText("Device Settings")).perform(click());
              //Scroll up
              onView(withText("Configure IRMA Base")).perform(swipeUp());
              onView(withText("Configure IRMA Base")).perform(swipeUp());
              onView(withText("Configure IRMA Base")).perform(swipeUp());
              onView(withText("Configure IRMA Base")).perform(swipeUp());
              onView(withText("Configure IRMA Base")).perform(swipeUp());
              onView(withText("Configure IRMA Base")).perform(swipeUp());
              onView(withText("Barcode Reader Timeout")).perform(swipeUp());
              onView(withText("Barcode Reader Timeout")).perform(swipeUp());
              onView(withText("Barcode Reader Timeout")).perform(swipeUp());
              //language
              onView(withText("Language")).perform(doubleClick());
              Spoon.screenshot(activity, "state_changed");
  
  
              //wait 1 min
              try {
                  Thread.sleep(1 * 60 * 1000);
              } catch (InterruptedException e) {
  
              }
          /* Clicks back button */
              onView(withId(R.id.btn_back)).perform(click());
              //clicks main menu button
              onView(withText("Main Menu")).perform(click());
  
          }
  }
  </code></pre>