Network state casting issue in java

I have been using a network check functionality in-app, but all things are available in Kotlin now the same thing wants to integrate in java facing some issue related to lazy calling.

This is how I can check network state in Kotlin

class MainActivity : AppCompatActivity(), ConnectivityStateListener {

    private lateinit var tv: TextView
    private val provider: ConnectivityProvider by lazy { ConnectivityProvider.createProvider(this) }

    @RequiresApi(Build.VERSION_CODES.M)
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        tv = findViewById(R.id.connectivity_state)
        val button = findViewById<View>(R.id.button)
        val currentState = findViewById<TextView>(R.id.current_state)

        button.setOnClickListener {
            val hasInternet = provider.getNetworkState().hasInternet()
            currentState.text = "Connectivity (synchronously): $hasInternet"
        }
    }

    override fun onStart() {
        super.onStart()
        provider.addListener(this)
    }

    override fun onStop() {
        super.onStop()
        provider.removeListener(this)
    }

    override fun onStateChange(state: NetworkState) {
        val hasInternet = state.hasInternet()
        tv.text = "Connectivity (via callback): $hasInternet"
    }

    private fun NetworkState.hasInternet(): Boolean {
        return (this as? ConnectedState)?.hasInternet == true
  



 }
}

this is how I integrated into Java

@Override
    protected void onStart() {
        super.onStart();
        provider=ConnectivityProvider.createProvider(this);
        provider.addListener(this);
    }


@Override
protected void onStop() {
    super.onStop();

    provider.removeListener(this);
}

  @Override
    public void onStateChange(@NotNull ConnectivityProvider.NetworkState state) {

        Log.d("To ConnectivityProvider-----", state.toString());
        Toast.makeText(LoginActivity.this, "Available", Toast.LENGTH_SHORT).show();
       if( hasInternet(state)){
           Toast.makeText(LoginActivity.this, "Available", Toast.LENGTH_SHORT).show();
       }else{
            Toast.makeText(LoginActivity.this, "No Internet", Toast.LENGTH_SHORT).show();

       }

    }

    private boolean hasInternet(@NotNull ConnectivityProvider.NetworkState state) {

        ConnectivityProvider.NetworkState.ConnectedState var2 = (ConnectivityProvider.NetworkState.ConnectedState)state;
        if (var2.getHasInternet()) {

            return true;
        }
        return false;
    }

java.lang.ClassCastException:
com.ro.other.connectivity.base.ConnectivityProvider$NetworkState$NotConnectedState
cannot be cast to
com.ro.other.connectivity.base.ConnectivityProvider$NetworkState$ConnectedState

gitlink help me to integrate this in java

>Solution :

The problem here is with type casting, not with lazy calling. The behaviour of the hasInternet methods in the given Kotlin and Java code is different.

Kotlin:

return (this as? ConnectedState)?.hasInternet == true

If the current NetworkState is not a ConnectedState, the typecast this as? ConnectedState will return null, and the method will return false.

Java:

ConnectivityProvider.NetworkState.ConnectedState var2 = (ConnectivityProvider.NetworkState.ConnectedState)state;
if (var2.getHasInternet()) {
    return true;
}
return false;

This code assumes that state is a ConnectedState (instead of checking it), and throws a ClassCastException if it is an instance of a different class.

The correct Java code for hasInternet method would be:

if (!(state instanceof ConnectivityProvider.NetworkState.ConnectedState)) {
    return false;
}
ConnectivityProvider.NetworkState.ConnectedState var2 = (ConnectivityProvider.NetworkState.ConnectedState)state;
if (var2.getHasInternet()) {
    return true;
}
return false;