CorePlane OkHttp DNS IPv4 preference

CorePlaneOkHttpClientFactory.java

// Customize OkHttp to add IPv4 DNS preference

import com.facebook.react.modules.network.OkHttpClientProvider;
import com.facebook.react.modules.network.OkHttpClientFactory;
import okhttp3.OkHttpClient;

public class CorePlaneOkHttpClientFactory implements OkHttpClientFactory {
    public OkHttpClient createNewNetworkModuleClient() {
        return OkHttpClientProvider.createClientBuilder()
            .dns(new CorePlaneOkHttpDNSSelector(CorePlaneOkHttpDNSSelector.IPvMode.IPV4_FIRST))
            .build();
    }
}

CorePlaneOkHttpDNSSelector.kt

import okhttp3.Dns
import java.net.Inet4Address
import java.net.Inet6Address
import java.net.InetAddress
import java.util.logging.Logger

class CorePlaneOkHttpDNSSelector(private val mode: IPvMode) : Dns {

  enum class IPvMode(val code: String) {
    SYSTEM("system"),
    IPV6_FIRST("ipv6"),
    IPV4_FIRST("ipv4"),
    IPV6_ONLY("ipv6only"),
    IPV4_ONLY("ipv4only");

    companion object {
        @JvmStatic
        fun fromString(ipMode: String): IPvMode =
        IPvMode.values().find { it.code == ipMode } ?: throw Exception("Unknown value $ipMode")
    }
  }

  override fun lookup(hostname: String): List<InetAddress> {
    var addresses = Dns.SYSTEM.lookup(hostname)

    addresses = when (mode) {
      IPvMode.IPV6_FIRST -> addresses.sortedBy { Inet4Address::class.java.isInstance(it) }
      IPvMode.IPV4_FIRST -> addresses.sortedBy { Inet6Address::class.java.isInstance(it) }
      IPvMode.IPV6_ONLY -> addresses.filter({ Inet6Address::class.java.isInstance(it) })
      IPvMode.IPV4_ONLY -> addresses.filter({ Inet4Address::class.java.isInstance(it) })
      IPvMode.SYSTEM -> addresses
    }

    //logger.fine("DJMOKHTTP ($hostname): " + addresses.joinToString(", ") { it.toString() })

    return addresses
  }

  companion object {
    private val logger = Logger.getLogger(CorePlaneOkHttpDNSSelector::class.java.name)
  }
}

MainApplication.java

public class MainApplication extends Application implements ReactApplication {

  // ...
  
@Override
  public void onCreate() {
    super.onCreate();
    OkHttpClientProvider.setOkHttpClientFactory(new CorePlaneOkHttpClientFactory());
  }

  // ...
}

Thanks for this!

For anyone else landing here that isn't a Java developer, for this to work I also needed to add package my.package.name; to the top of both the .java and .kt files. (same package name as you have at the top of MainApplication.java

And also needed apply plugin: 'kotlin-android' in android/app/build.gradle.

Here's a related thread with further details:
facebook/react-native#32730

Hi @andreialecu : Related to issue aws-amplify/amplify-js#5539
I tried to apply this solution, but it don't work now
Do you have any other solution to fix this ?

Thank you so much

This is the solution I'm using and it works for me.

This fixed my issue too. Now I'm able to make network calls right after app opens, no need to wait timeout or fallback to ipv4 for 3 minutes.

Helped me as well! Thank you

Hi, this solution works on debug but not on the release, any workaround?

when i try to compile with this i get:
cannot find symbol
OkHttpClientProvider.setOkHttpClientFactory(new CorePlaneOkHttpClientFactory());
^
symbol: variable OkHttpClientProvider
location: class MainApplication
what is the solution?

How can I apply this to an Expo app?
@andreialecu @andac-ozcan @danmaas

when i try to compile with this i get: cannot find symbol OkHttpClientProvider.setOkHttpClientFactory(new CorePlaneOkHttpClientFactory()); ^ symbol: variable OkHttpClientProvider location: class MainApplication what is the solution?

@HodayaGruz I also got this error, did You find how to solve it?

when i try to compile with this i get: cannot find symbol OkHttpClientProvider.setOkHttpClientFactory(new CorePlaneOkHttpClientFactory()); ^ symbol: variable OkHttpClientProvider location: class MainApplication what is the solution?

@HodayaGruz I also got this error, did You find how to solve it?

You should import this:
import com.facebook.react.modules.network.OkHttpClientProvider;