在android应用程序上使用API REST接口进行用户身份验证

Question

private void loginpage() {
    final Button button = findViewById(R.id.button4);
    button.setOnClickListener(v -> {
        String username = findViewById(R.id.editTextTextPassword).toString();
        String password = findViewById(R.id.editTextTextPersonName).toString();

        try {
            webUntisAPI.login(username,password,"Spengergasse"); //Accesses the API to login
            setContentView(R.layout.activity_main);
            mainpage();
        }catch (RuntimeException ignored){
             //On fail don't switch view
        }

    });
}

W/System.err:     at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1600)
        at java.net.Inet6AddressImpl.lookupHostByName(Inet6AddressImpl.java:115)
        at java.net.Inet6AddressImpl.lookupAllHostAddr(Inet6AddressImpl.java:103)
        at java.net.InetAddress.getAllByName(InetAddress.java:1152)
        at okhttp3.Dns$Companion$DnsSystem.lookup(Dns.kt:49)
        at okhttp3.internal.connection.RouteSelector.resetNextInetSocketAddress(RouteSelector.kt:164)
        at okhttp3.internal.connection.RouteSelector.nextProxy(RouteSelector.kt:129)
        at okhttp3.internal.connection.RouteSelector.next(RouteSelector.kt:71)
        at okhttp3.internal.connection.ExchangeFinder.findConnection(ExchangeFinder.kt:205)
        at okhttp3.internal.connection.ExchangeFinder.findHealthyConnection(ExchangeFinder.kt:106)
W/System.err:     at okhttp3.internal.connection.ExchangeFinder.find(ExchangeFinder.kt:74)
        at okhttp3.internal.connection.RealCall.initExchange$okhttp(RealCall.kt:255)
        at okhttp3.internal.connection.ConnectInterceptor.intercept(ConnectInterceptor.kt:32)
        at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.kt:109)
        at okhttp3.internal.cache.CacheInterceptor.intercept(CacheInterceptor.kt:95)
        at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.kt:109)
        at okhttp3.internal.http.BridgeInterceptor.intercept(BridgeInterceptor.kt:83)
W/System.err:     at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.kt:109)
        at okhttp3.internal.http.RetryAndFollowUpInterceptor.intercept(RetryAndFollowUpInterceptor.kt:76)
        at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.kt:109)
        at okhttp3.internal.connection.RealCall.getResponseWithInterceptorChain$okhttp(RealCall.kt:201)
        at okhttp3.internal.connection.RealCall.execute(RealCall.kt:154)
W/System.err:     at com.example.myapplication.WebUntisAPI.login(WebUntisAPI.java:49)
        at com.example.myapplication.MainActivity.lambda$loginpage$0$MainActivity(MainActivity.java:56)
        at com.example.myapplication.-$$Lambda$MainActivity$f4xelUsFrwZaMU-fM7MXdfynjRQ.onClick(Unknown Source:2)
        at android.view.View.performClick(View.java:7448)
        at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:1119)
        at android.view.View.performClickInternal(View.java:7425)
W/System.err:     at android.view.View.access$3600(View.java:810)
        at android.view.View$PerformClick.run(View.java:28296)
        at android.os.Handler.handleCallback(Handler.java:938)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:223)
        at android.app.ActivityThread.main(ActivityThread.java:7656)
W/System.err:     at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)
I/Choreographer: Skipped 33 frames!  The application may be doing too much work on its main thread.

StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
        StrictMode.setThreadPolicy(policy);