在正常工作的应用中突然发生网络调用失败并出现协议异常。 该应用程序一直工作到昨天，今天所有的网络呼叫都失败了。这些调用适用于HTTP，但使用HTTPS失败。
这是日志，
java.net.ProtocolException: Expected ':status' header not present
10-18 14:59:01.103 30746-30746/? W/System.err: at okhttp3.internal.http.Http2xStream.readHttp2HeadersList(Http2xStream.java:262)
10-18 14:59:01.103 30746-30746/? W/System.err: at okhttp3.internal.http.Http2xStream.readResponseHeaders(Http2xStream.java:145)
10-18 14:59:01.103 30746-30746/? W/System.err: at okhttp3.internal.http.CallServerInterceptor.intercept(CallServerInterceptor.java:53)
10-18 14:59:01.103 30746-30746/? W/System.err: at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:92)
10-18 14:59:01.103 30746-30746/? W/System.err: at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:67)
10-18 14:59:01.103 30746-30746/? W/System.err: at codmob.com.campuswallet.app.ApiClient$1.intercept(ApiClient.java:66)
10-18 14:59:01.103 30746-30746/? W/System.err: at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:92)
10-18 14:59:01.103 30746-30746/? W/System.err: at okhttp3.internal.connection.ConnectInterceptor.intercept(ConnectInterceptor.java:45)
10-18 14:59:01.103 30746-30746/? W/System.err: at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:92)
10-18 14:59:01.103 30746-30746/? W/System.err: at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:67)
10-18 14:59:01.103 30746-30746/? W/System.err: at okhttp3.internal.cache.CacheInterceptor.intercept(CacheInterceptor.java:109)
10-18 14:59:01.103 30746-30746/? W/System.err: at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:92)
10-18 14:59:01.103 30746-30746/? W/System.err: at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:67)
10-18 14:59:01.103 30746-30746/? W/System.err: at okhttp3.internal.http.BridgeInterceptor.intercept(BridgeInterceptor.java:93)
10-18 14:59:01.103 30746-30746/? W/System.err: at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:92)
10-18 14:59:01.103 30746-30746/? W/System.err: at okhttp3.internal.http.RetryAndFollowUpInterceptor.intercept(RetryAndFollowUpInterceptor.java:124)
10-18 14:59:01.103 30746-30746/? W/System.err: at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:92)
10-18 14:59:01.104 30746-30746/? W/System.err: at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:67)
10-18 14:59:01.104 30746-30746/? W/System.err: at okhttp3.RealCall.getResponseWithInterceptorChain(RealCall.java:170)
10-18 14:59:01.104 30746-30746/? W/System.err: at okhttp3.RealCall.access$100(RealCall.java:33)
10-18 14:59:01.104 30746-30746/? W/System.err: at okhttp3.RealCall$AsyncCall.execute(RealCall.java:120)
10-18 14:59:01.104 30746-30746/? W/System.err: at okhttp3.internal.NamedRunnable.run(NamedRunnable.java:32)
10-18 14:59:01.104 30746-30746/? W/System.err: at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1133)
10-18 14:59:01.104 30746-30746/? W/System.err: at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:607)
10-18 14:59:01.104 30746-30746/? W/System.err: at java.lang.Thread.run(Thread.java:761)
答案 0 :(得分：21)
compile 'com.squareup.okhttp3:okhttp:3.9.0'
compile 'com.squareup.retrofit2:retrofit:2.3.0'
答案 1 :(得分：7)
今天遇到了同样的问题。原因是将服务器上的nginx更新为最新版本（1.13.6）。询问你的后端团队他们是否没有在服务器上更新nginx。
nginx changelog - http://nginx.org/en/CHANGES
答案 2 :(得分：7)
我正在使用OkHttp2（2.7.5），我通过强制客户端使用HTTP 1.1协议解决了这个问题
OkHttpClient client = new OkHttpClient();
client.setProtocols(Arrays.asList(Protocol.HTTP_1_1)); // <- add this line
答案 3 :(得分：1)
我使用okhttp3（okhttp-3.4.1），okhttp3与HTTP_1.1协议不兼容，需要手动添加。你可以看到Official link
OkHttpClient.Builder builder = new OkHttpClient.Builder();
//protocols
List<Protocol> protocols = new ArrayList<Protocol>();
protocols.add(Protocol.HTTP_1_1);
protocols.add(Protocol.HTTP_2);
builder.protocols(protocols);