调用

AWSMobileclient.getInstance().getTokens().getIdToken().getclaim("sub");

立即登录。

AWSMobileclient.getInstance().signIn(username,password....

但是，当我恢复活动（转到另一个应用程序）并再次尝试获取令牌时，出现错误：

D/AWSMobileclient: waitForSignIn: userState:SIGNED_IN
D/AWSMobileclient: Inspecting user state details
D/AWSMobileclient: hasFederatedToken: false provider: cognito-idp.us-east-1.amazonaws.com/us-east-1_.....
D/AWSMobileclient: hasFederatedToken: false provider: cognito-idp.us-east-1.amazonaws.com/us-east-1_
D/CognitoCachingCredentialsProvider: Clearing credentials from SharedPreferences
D/CognitoCachingCredentialsProvider: Clearing credentials from SharedPreferences

W/AWSMobileclient: Failed to federate the tokens
    android.os.NetworkOnmainThreadException
        at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1450)
        at java.net.Inet6AddressImpl.lookupHostByName(Inet6AddressImpl.java:102)
        at java.net.Inet6AddressImpl.lookupAllHostAddr(Inet6AddressImpl.java:90)
        at java.net.Inetaddress.getallByName(Inetaddress.java:787)
        at com.android.okhttp.Dns$1.lookup(Dns.java:39)

不知道为什么。这是我当前的awsconfiguration：

{
    "IdentityManager": {
        "Default": {}
    },"CredentialsProvider": {
        "CognitoIdentity": {
            "Default": {
                "PoolId": "us-east-1:088e7bc3...","Region": "us-east-1"
            }
        }
    },"CognitoUserPool": {
        "Default": {
            "PoolId": "us-east-1_....","AppClientId": "50e3s5e....","AppClientSecret": "1mbug...","Region": "us-east-1"
        }
    }
}