Не удалось вызвать динамический метод в статическом контексте?
Они созданы с использованием Android Studio, как в разделе Как изменить фиктивный контент в мастере / детализации Android?, Я изменил статический метод в dummyContent ниже:
public void fetchData() {
// Add some sample items.
for (int i = 1; i <= COUNT; i++) {
addItem(createDummyItem(i));
}
Authenticator.setDefault(new Authenticator() {
@Override
protected PasswordAuthentication getPasswordAuthentication() {
return new PasswordAuthentication(
DummyContent.UNAME, DummyContent.PASSWORD.toCharArray());
}
});
try {
DummyContentRegistry registry = new XMLDummyContentParser(DummyContent.url).parse();
for (DummyContent.DummyItem t: registry.getTeachers()) {
DummyContent.addItem(t);
}
} catch (Exception e) {
fail("Exception should not have been thrown");
}
}
пока выше пройден тест:
public class DummyContentRegistryTest {
@Before
public void buildRegistry() {}
@Test
public void testFetchData() {
Assert.assertEquals(0,DummyContent.ITEMS.size());
new DummyContent().fetchData();
Assert.assertEquals(27,DummyContent.ITEMS.size());// two more items are added through parsing xml on a website
}
}
Однако, когда я вызываю метод в MainActivity.onCreate, он завершается ошибкой "Исключение не должно быть выброшено". Зачем? Вот пример сбоя вызова
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (DummyContent.ITEMS.isEmpty()) {
new DummyContent().fetchData();
}
......
}
Я не знаю, похожа ли проблема на вызов нестатического метода в статическом методе в Java, но я, очевидно, попробовал способ, с которым большинство из них согласились.
[ 07-25 04:04:56.442 23983:24025 D/ ]
HostConnection::get() New Host Connection established 0x7f1b57910500, tid 24025
07-25 04:04:56.460 23983-24025/*****private*****.myapplication I/OpenGLRenderer: Initialized EGL, version 1.4
07-25 04:04:56.873 23983-23983/*****private*****.myapplication I/Choreographer: Skipped 32 frames! The application may be doing too much work on its main thread.
07-25 04:05:07.474 23983-23983/*****private*****.myapplication W/System.err: java.io.IOException: Couldn't open *****private*****
07-25 04:05:07.475 23983-23983/*****private*****.myapplication W/System.err: at org.apache.harmony.xml.ExpatParser.openUrl(ExpatParser.java:755)
07-25 04:05:07.475 23983-23983/*****private*****.myapplication W/System.err: at org.apache.harmony.xml.ExpatReader.parse(ExpatReader.java:292)
07-25 04:05:07.475 23983-23983/*****private*****.myapplication W/System.err: at javax.xml.parsers.SAXParser.parse(SAXParser.java:390)
07-25 04:05:07.475 23983-23983/*****private*****.myapplication W/System.err: at javax.xml.parsers.SAXParser.parse(SAXParser.java:266)
07-25 04:05:07.475 23983-23983/*****private*****.myapplication W/System.err: at *****private*****.myapplication.dummy.XMLDummyContentParser.parse(XMLDummyContentParser.java:33)
07-25 04:05:07.475 23983-23983/*****private*****.myapplication W/System.err: at *****private*****.myapplication.dummy.DummyContent.fetchData(DummyContent.java:53)
07-25 04:05:07.475 23983-23983/*****private*****.myapplication W/System.err: at *****private*****.myapplication.MainActivity.onCreate(MainActivity.java:52)
07-25 04:05:07.475 23983-23983/*****private*****.myapplication W/System.err: at android.app.Activity.performCreate(Activity.java:6237)
07-25 04:05:07.475 23983-23983/*****private*****.myapplication W/System.err: at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107)
07-25 04:05:07.475 23983-23983/*****private*****.myapplication W/System.err: at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369)
07-25 04:05:07.475 23983-23983/*****private*****.myapplication W/System.err: at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
07-25 04:05:07.475 23983-23983/*****private*****.myapplication W/System.err: at android.app.ActivityThread.-wrap11(ActivityThread.java)
07-25 04:05:07.475 23983-23983/*****private*****.myapplication W/System.err: at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
07-25 04:05:07.475 23983-23983/*****private*****.myapplication W/System.err: at android.os.Handler.dispatchMessage(Handler.java:102)
07-25 04:05:07.475 23983-23983/*****private*****.myapplication W/System.err: at android.os.Looper.loop(Looper.java:148)
07-25 04:05:07.475 23983-23983/*****private*****.myapplication W/System.err: at android.app.ActivityThread.main(ActivityThread.java:5417)
07-25 04:05:07.475 23983-23983/*****private*****.myapplication W/System.err: at java.lang.reflect.Method.invoke(Native Method)
07-25 04:05:07.475 23983-23983/*****private*****.myapplication W/System.err: at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
07-25 04:05:07.475 23983-23983/*****private*****.myapplication W/System.err: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
07-25 04:05:07.475 23983-23983/*****private*****.myapplication W/System.err: Caused by: android.os.NetworkOnMainThreadException
07-25 04:05:07.475 23983-23983/*****private*****.myapplication W/System.err: at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1273)
07-25 04:05:07.475 23983-23983/*****private*****.myapplication W/System.err: at java.net.InetAddress.lookupHostByName(InetAddress.java:431)
07-25 04:05:07.475 23983-23983/*****private*****.myapplication W/System.err: at java.net.InetAddress.getAllByNameImpl(InetAddress.java:252)
07-25 04:05:07.475 23983-23983/*****private*****.myapplication W/System.err: at java.net.InetAddress.getAllByName(InetAddress.java:215)
07-25 04:05:07.475 23983-23983/*****private*****.myapplication W/System.err: at com.android.okhttp.internal.Network$1.resolveInetAddresses(Network.java:29)
07-25 04:05:07.475 23983-23983/*****private*****.myapplication W/System.err: at com.android.okhttp.internal.http.RouteSelector.resetNextInetSocketAddress(RouteSelector.java:188)
07-25 04:05:07.475 23983-23983/*****private*****.myapplication W/System.err: at com.android.okhttp.internal.http.RouteSelector.nextProxy(RouteSelector.java:157)
07-25 04:05:07.475 23983-23983/*****private*****.myapplication W/System.err: at com.android.okhttp.internal.http.RouteSelector.next(RouteSelector.java:100)
07-25 04:05:07.475 23983-23983/*****private*****.myapplication W/System.err: at com.android.okhttp.internal.http.HttpEngine.createNextConnection(HttpEngine.java:357)
07-25 04:05:07.475 23983-23983/*****private*****.myapplication W/System.err: at com.android.okhttp.internal.http.HttpEngine.nextConnection(HttpEngine.java:340)
07-25 04:05:07.476 23983-23983/*****private*****.myapplication W/System.err: at com.android.okhttp.internal.http.HttpEngine.connect(HttpEngine.java:330)
07-25 04:05:07.476 23983-23983/*****private*****.myapplication W/System.err: at com.android.okhttp.internal.http.HttpEngine.sendRequest(HttpEngine.java:248)
07-25 04:05:07.476 23983-23983/*****private*****.myapplication W/System.err: at com.android.okhttp.internal.huc.HttpURLConnectionImpl.execute(HttpURLConnectionImpl.java:433)
07-25 04:05:07.476 23983-23983/*****private*****.myapplication W/System.err: at com.android.okhttp.internal.huc.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:384)
07-25 04:05:07.476 23983-23983/*****private*****.myapplication W/System.err: at com.android.okhttp.internal.huc.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:231)
07-25 04:05:07.476 23983-23983/*****private*****.myapplication W/System.err: at com.android.okhttp.internal.huc.DelegatingHttpsURLConnection.getInputStream(DelegatingHttpsURLConnection.java:210)
07-25 04:05:07.476 23983-23983/*****private*****.myapplication W/System.err: at com.android.okhttp.internal.huc.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java)
07-25 04:05:07.476 23983-23983/*****private*****.myapplication W/System.err: at org.apache.harmony.xml.ExpatParser.openUrl(ExpatParser.java:753)
07-25 04:05:07.476 23983-23983/*****private*****.myapplication W/System.err: ... 18 more
07-25 04:05:07.483 23983-23983/*****private*****.myapplication D/AndroidRuntime: Shutting down VM
07-25 04:05:07.484 23983-23983/*****private*****.myapplication E/AndroidRuntime: FATAL EXCEPTION: main
Process: ******private*******, PID: 23983
java.lang.RuntimeException: Unable to start activity ComponentInfo{******private*******.myapplication.MainActivity}: java.lang.IllegalStateException: Already attached
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2416)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: java.lang.IllegalStateException: Already attached
at android.support.v4.app.FragmentManagerImpl.attachController(FragmentManager.java:2126)
at android.support.v4.app.FragmentController.attachHost(FragmentController.java:104)
at android.support.v4.app.FragmentActivity.onCreate(FragmentActivity.java:313)
at android.support.v7.app.AppCompatActivity.onCreate(AppCompatActivity.java:85)
at *****private*****.myapplication.MainActivity.onCreate(MainActivity.java:55)
at android.app.Activity.performCreate(Activity.java:6237)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
2 ответа
Исключение e, который вы ловите, может содержать полезную информацию о том, что именно пошло не так. Делать e.printStackTrace(); внутри вашего catch-Блок для печати всей доступной информации на стандартный вывод. Если это не поможет вам решить проблему, опубликуйте здесь трассировку стека.
Вы не можете манипулировать UI thread от background thread вот почему вы получаете эту ошибку.
ClassName.this.runOnUiThread(new Runnable() {
public void run() {
//Do something on UiThread
// enclose your UI manipulated code here in these braces.
}
});