SocketTimeoutException android retrofit

Question

我正在建立一個安穩的客戶端，在我的android應用中使用翻新，但是我試圖從我的web服務中檢索數據時遇到異常， 第一次調用沒有例外，但我改變參數並重試得到新的數據，我得到波紋管

提到的異常，這是我的服務生成器類

public class ServiceGenerator { 

public static final String API_BASE_URL = "http://192.168.43.109:9988/Serv/"; 

private static OkHttpClient.Builder httpClient = new OkHttpClient.Builder(); 



private static Retrofit.Builder builder = 
     new Retrofit.Builder() 
       .baseUrl(API_BASE_URL) 
       .addConverterFactory(GsonConverterFactory.create()); 

public static <S> S createService(Class<S> serviceClass) { 
    Retrofit retrofit = builder.client(httpClient.build()).build(); 
    return retrofit.create(serviceClass); 
}} 

，這是堆棧跟蹤我得到：

W/System.err: java.net.SocketTimeoutException 
W/System.err:  at java.net.PlainSocketImpl.read(PlainSocketImpl.java:488) 
W/System.err:  at java.net.PlainSocketImpl.access$000(PlainSocketImpl.java:37) 
W/System.err:  at java.net.PlainSocketImpl$PlainSocketInputStream.read(PlainSocketImpl.java:237) 
W/System.err:  at okio.Okio$2.read(Okio.java:140) 
W/System.err:  at okio.AsyncTimeout$2.read(AsyncTimeout.java:238) 
W/System.err:  at okio.RealBufferedSource.indexOf(RealBufferedSource.java:325) 
W/System.err:  at okio.RealBufferedSource.indexOf(RealBufferedSource.java:314) 
W/System.err:  at okio.RealBufferedSource.readUtf8LineStrict(RealBufferedSource.java:210) 
W/System.err:  at okhttp3.internal.http.Http1xStream.readResponse(Http1xStream.java:184) 
W/System.err:  at okhttp3.internal.http.Http1xStream.readResponseHeaders(Http1xStream.java:125) 
W/System.err:  at okhttp3.internal.http.HttpEngine.readNetworkResponse(HttpEngine.java:775) 
W/System.err:  at okhttp3.internal.http.HttpEngine.access$200(HttpEngine.java:86) 
W/System.err:  at okhttp3.internal.http.HttpEngine$NetworkInterceptorChain.proceed(HttpEngine.java:760) 
W/System.err:  at okhttp3.internal.http.HttpEngine.readResponse(HttpEngine.java:613) 
W/System.err:  at okhttp3.RealCall.getResponse(RealCall.java:244) 
W/System.err:  at okhttp3.RealCall$ApplicationInterceptorChain.proceed(RealCall.java:201) 
W/System.err:  at okhttp3.RealCall.getResponseWithInterceptorChain(RealCall.java:163) 
W/System.err:  at okhttp3.RealCall.execute(RealCall.java:57) 
W/System.err:  at retrofit2.OkHttpCall.execute(OkHttpCall.java:174) 
W/System.err:  at retrofit2.ExecutorCallAdapterFactory$ExecutorCallbackCall.execute(ExecutorCallAdapterFactory.java:89) 
W/System.err:  at com.example.admin.theapp.ListPersonne$GetPersonnesAsyncTask.doInBackground(ListPersonne.java:418) 
W/System.err:  at com.example.admin.theapp.ListPersonne$GetPersonnesAsyncTask.doInBackground(ListPersonne.java:409) 
W/System.err:  at android.os.AsyncTask$2.call(AsyncTask.java:288) 
W/System.err:  at java.util.concurrent.FutureTask.run(FutureTask.java:237) 
W/System.err:  at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231) 
W/System.err:  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112) 
W/System.err:  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587) 
W/System.err:  at java.lang.Thread.run(Thread.java:818) 
W/System.err: java.lang.NullPointerException: Attempt to invoke interface method 'java.util.Iterator java.util.List.iterator()' on a null object reference 
W/System.err:  at com.example.admin.theapp.ListPersonne.onCreate(ListPersonne.java:143) 
W/System.err:  at android.app.Activity.performCreate(Activity.java:6374) 
W/System.err:  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1119) 
W/System.err:  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2743) 
W/System.err:  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2855) 
W/System.err:  at android.app.ActivityThread.access$900(ActivityThread.java:181) 
W/System.err:  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1474) 
W/System.err:  at android.os.Handler.dispatchMessage(Handler.java:102) 
W/System.err:  at android.os.Looper.loop(Looper.java:145) 
W/System.err:  at android.app.ActivityThread.main(ActivityThread.java:6117) 
W/System.err:  at java.lang.reflect.Method.invoke(Native Method) 
W/System.err:  at java.lang.reflect.Method.invoke(Method.java:372) 
W/System.err:  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1399) 
W/System.err:  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1194) 

Answer 1

private OkHttpClient getClient() { 
    OkHttpClient client = new OkHttpClient.Builder() 
    .connectTimeout(5, TimeUnit.MINUTES) 
    .readTimeout(5, TimeUnit.MINUTES) 
    .build(); 
    return client; 
} 

Answer 2

正如您所見，錯誤是java.lang.NullPointerException: Attempt to invoke interface method 'java.util.Iterator java.util.List.iterator()' on a null object reference。這很可能是因爲當服務器做出響應或拋出其他錯誤時，您嘗試迭代到人員空列表。檢查你的回調監聽器或Observable（如果你使用的是RxJava）。