A roboguice provider for creating a User-Agent string on android

Usage.java

public class MyModule extends AbstractModule {
  @Override
  void configure() {
    bind(String.class).annotatedWith(UserAgent.class).to(UserAgentProvider.class);
  }
}

public class MyComponent {
  String userAgent;

  @Inject
  public MyComponent(@UserAgent String userAgent) {
    this.userAgent = userAgent;
  }
}

UserAgent.java

import com.google.inject.BindingAnnotation;

import java.lang.annotation.Retention;
import java.lang.annotation.Target;

import static java.lang.annotation.ElementType.*;
import static java.lang.annotation.RetentionPolicy.RUNTIME;

@BindingAnnotation @Target({ FIELD, PARAMETER, METHOD }) @Retention(RUNTIME)
public @interface UserAgent {}

UserAgentProvider.java

import android.content.Context;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.content.res.Configuration;
import android.os.Build;
import android.util.DisplayMetrics;
import com.google.inject.Inject;
import com.google.inject.Provider;
import com.google.inject.Singleton;

import java.util.Locale;

@Singleton
public class UserAgentProvider implements Provider<String> {
    Context application;
    volatile String userAgent;

    @Inject
    public UserAgentProvider(Context application) {
        this.application = application.getApplicationContext();
    }

    @Override
    public String get() {
        if (userAgent == null) {
            synchronized (UserAgentProvider.class) {
                if (userAgent == null) {
                    userAgent = createUserAgentString();
                }
            }
        }
        return userAgent;
    }

    private String createUserAgentString() {
        String appName = "";
        String appVersion = "";
        int height = 0;
        int width = 0;
        DisplayMetrics display = application.getResources().getDisplayMetrics();
        Configuration config = application.getResources().getConfiguration();

        // Always send screen dimension for portrait mode
        if (config.orientation == Configuration.ORIENTATION_LANDSCAPE) {
            height = display.widthPixels;
            width = display.heightPixels;
        } else {
            width = display.widthPixels;
            height = display.heightPixels;
        }

        try {
            PackageInfo packageInfo = application.getPackageManager().getPackageInfo(application.getPackageName(), PackageManager.GET_CONFIGURATIONS);
            appName = packageInfo.packageName;
            appVersion = packageInfo.versionName;
        } catch (PackageManager.NameNotFoundException ignore) {
            // this should never happen, we are looking up ourself
        }

        // Tries to conform to default android UA string without the Safari / webkit noise, plus adds the screen dimensions
        return String.format("%1$s/%2$s (%3$s; U; Android %4$s; %5$s-%6$s; %12$s Build/%7$s; %8$s) %9$dX%10$d %11$s %12$s"
            , appName
            , appVersion
            , System.getProperty("os.name", "Linux")
            , Build.VERSION.RELEASE
            , config.locale.getLanguage().toLower()
            , config.locale.getCountry().toLower()
            , Build.ID
            , Build.BRAND
            , width
            , height
            , Build.MANUFACTURER
            , Build.MODEL);
    }
}