我正尝试在 Android 中向我的服务器发出同步请求。 (代码在普通 Java 项目中完美运行)
我知道不应该在主线程上完成同步请求,所以我在网络完成的地方启动了一个新线程。我也知道可以进行异步调用,但同步调用更适合我的用例。
bool networkingIsDoneHere(){
dostuff();
int number = doNetworkCall();
if(number < 500){
return true;
}
return false
}
问题是我仍然收到“NetworkOnMainThreadException”错误。改造是否以某种方式在主线程上运行,而在副线程上执行?
开始新线程:
Thread timerThread = new Thread() {
@Override
public void run() {
while (true) {
try {
networkingIsDoneHere();
sleep(getExecutionInterval());
} catch (Exception e) {
e.printStackTrace();
}
}
}
};
@Override
public void startRule() {
timerThread.start();
}
改造代码
private Retrofit createRetrofitAdapter() throws Exception {
return retrofit = new Retrofit.Builder()
.baseUrl("https://maps.googleapis.com/maps/api/")
.addConverterFactory(GsonConverterFactory.create())
.build();
}
public interface ApiGoogleMapsService {
@GET("url...")
Call<MapApiCall> getDurationJson(@Query("origins") String origin, @Query("destinations") String destination);
}
错误:
Caused by: android.os.NetworkOnMainThreadException
be.kul.gj.annotationfw W/System.err: at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1273)
be.kul.gj.annotationfw W/System.err: at com.android.org.conscrypt.OpenSSLSocketImpl.shutdownAndFreeSslNative(OpenSSLSocketImpl.java:1131)
be.kul.gj.annotationfw W/System.err: at com.android.org.conscrypt.OpenSSLSocketImpl.close(OpenSSLSocketImpl.java:1126)
be.kul.gj.annotationfw W/System.err: at okhttp3.internal.Util.closeQuietly(Util.java:105)
be.kul.gj.annotationfw W/System.err: at okhttp3.internal.http.StreamAllocation.deallocate(StreamAllocation.java:260)
be.kul.gj.annotationfw W/System.err: at okhttp3.internal.http.StreamAllocation.connectionFailed(StreamAllocation.java:289)
be.kul.gj.annotationfw W/System.err: at okhttp3.internal.http.HttpEngine.close(HttpEngine.java:429)
be.kul.gj.annotationfw W/System.err: at okhttp3.RealCall.getResponse(RealCall.java:270)
be.kul.gj.annotationfw W/System.err: at okhttp3.RealCall$ApplicationInterceptorChain.proceed(RealCall.java:198)
be.kul.gj.annotationfw W/System.err: at okhttp3.RealCall.getResponseWithInterceptorChain(RealCall.java:160)
be.kul.gj.annotationfw W/System.err: at okhttp3.RealCall.execute(RealCall.java:57)
be.kul.gj.annotationfw W/System.err: at retrofit2.OkHttpCall.execute(OkHttpCall.java:177)
be.kul.gj.annotationfw W/System.err: at retrofit2.ExecutorCallAdapterFactory$ExecutorCallbackCall.execute(ExecutorCallAdapterFactory.java:87)
be.kul.gj.annotationfw W/System.err: at model.GoogleMapsAccess.getTravelDuration(GoogleMapsAccess.java:52)
be.kul.gj.annotationfw W/System.err: at rule.RoutePickupRule.condition(RoutePickupRule.java:40)
最佳答案
Retrofit 无需自己启动新线程,而是可以在单独的线程上自动执行请求。您可以通过调用 enqueue();
来完成此操作。
Call<MapApiCall> call = api.getDurationJson(foo);
call.enqueue(new Callback<MapApiCall>() {
@Override
public void onResponse(Call<MapApiCall> call, Response<MapApiCall> response) {
//Do something with response
}
@Override
public void onFailure(Call<MapApiCall> call, Throwable t) {
//Do something with failure
}
});
如果您想要同步请求,请在单独的线程中使用 execute()
:
Call<MapApiCall> call = api.getDurationJson();
MapApiCall apiCall = call.execute().body();
如果您出于某种原因想要在不使用线程的情况下禁用 NetworkOnMainThreadException
,请使用:
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
但是,这真的不推荐,如果你不知道 StrictMode
的作用,请不要使用它。
关于android - 改造 2 错误 : NetworkOnMainThreadException,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/35796850/