Android 9.0 and above solutions to the failure to connect to wifi

Starting from Android9, the API of WIFI has changed:
addNetwork(WifiConfiguration config)
This method has been deprecated in API level Q)
see addNetworkSuggestions(java.util.List), removeNetworkSuggestions(java.util.List) new API added When a Wi-Fi network is considered, automatically connect to the wireless network. Compatibility Note: For apps targeting Build.VERSION_CODES.Q or higher, this API will always return -1.

Don't talk nonsense and go directly to the code:
first, you need to add permissions to the manifest file:

 <uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>
 <uses-permission android:name="android.permission.CHANGE_WIFI_STATE"/>
 <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
 <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-permission android:name="android.permission.CHANGE_NETWORK_STATE"/>
<uses-permission android:name="android.permission.WRITE_SETTINGS" />

Secondly, the activity needs to dynamically apply for permissions. The code is as follows:
public class MainActivity extends AppCompatActivity { private static String[] PERMISSIONS_STORAGE = { Manifest.permission.ACCESS_COARSE_LOCATION, Manifest.permission.ACCESS_FINE_LOCATION};

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    verifyStoragePermissions(MainActivity.this);

    findViewById(R.id.but1).setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            test("ssid","密码");
        }
    });
    findViewById(R.id.but2).setOnClickListener(new View.OnClickListener() {
        private WifiUtils instance;
        @Override
        public void onClick(View v) {
            test("ssid-WIFI","密码");
        }
    });

}
public void verifyStoragePermissions(Activity activity) {
ActivityCompat.requestPermissions(activity, PERMISSIONS_STORAGE, 1);

}

public void test(String name,String wpd)
{
    if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.Q)
    {
        NetworkSpecifier specifier =
                new WifiNetworkSpecifier.Builder()
                        .setSsidPattern(new PatternMatcher(name, PatternMatcher.PATTERN_PREFIX))
                        .setWpa2Passphrase(wpd)
                        .build();

        NetworkRequest request =
                new NetworkRequest.Builder()
                        .addTransportType(NetworkCapabilities.TRANSPORT_WIFI)
                        .removeCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET)
                        .setNetworkSpecifier(specifier)
                        .build();

        ConnectivityManager connectivityManager = (ConnectivityManager)
                getSystemService(Context.CONNECTIVITY_SERVICE);

        ConnectivityManager.NetworkCallback networkCallback = new ConnectivityManager.NetworkCallback() {
            @Override
            public void onAvailable(Network network) {
                // do success processing here..
            }

            @Override
            public void onUnavailable() {
                // do failure processing here..
            }
        };
        connectivityManager.requestNetwork(request, networkCallback);
        // Release the request when done.
        // connectivityManager.unregisterNetworkCallback(networkCallback);
    }
}

}

Perfectly solve the problem of wifi connection failure above Android9.0~