android MDNSBrowseHandler示例代码

以下是使用MDNSBrowseHandler的Android示例代码：

import android.net.nsd.NsdManager;
import android.net.nsd.NsdServiceInfo;
import android.os.Bundle;
import android.util.Log;

import androidx.appcompat.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity {

    private static final String TAG = "MainActivity";
    private static final String SERVICE_TYPE = "_http._tcp.";

    private NsdManager.DiscoveryListener mDiscoveryListener;
    private NsdManager mNsdManager;

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

        mNsdManager = (NsdManager) getSystemService(NSD_SERVICE);

        mDiscoveryListener = new NsdManager.DiscoveryListener() {
            @Override
            public void onStartDiscoveryFailed(String serviceType, int errorCode) {
                Log.e(TAG, "onStartDiscoveryFailed: " + errorCode);
            }

            @Override
            public void onStopDiscoveryFailed(String serviceType, int errorCode) {
                Log.e(TAG, "onStopDiscoveryFailed: " + errorCode);
            }

            @Override
            public void onDiscoveryStarted(String serviceType) {
                Log.d(TAG, "onDiscoveryStarted: " + serviceType);
            }

            @Override
            public void onDiscoveryStopped(String serviceType) {
                Log.d(TAG, "onDiscoveryStopped: " + serviceType);
            }

            @Override
            public void onServiceFound(NsdServiceInfo serviceInfo) {
                Log.d(TAG, "onServiceFound: " + serviceInfo.getServiceName());

                // Resolve the service to get the IP address and port
                mNsdManager.resolveService(serviceInfo, new NsdManager.ResolveListener() {
                    @Override
                    public void onResolveFailed(NsdServiceInfo serviceInfo, int errorCode) {
                        Log.e(TAG, "onResolveFailed: " + errorCode);
                    }

                    @Override
                    public void onServiceResolved(NsdServiceInfo serviceInfo) {
                        Log.d(TAG, "onServiceResolved: " + serviceInfo.getHost() + ":" + serviceInfo.getPort());
                    }
                });
            }

            @Override
            public void onServiceLost(NsdServiceInfo serviceInfo) {
                Log.d(TAG, "onServiceLost: " + serviceInfo.getServiceName());
            }
        };

        mNsdManager.discoverServices(SERVICE_TYPE, NsdManager.PROTOCOL_DNS_SD, mDiscoveryListener);
    }

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

        mNsdManager.stopServiceDiscovery(mDiscoveryListener);
    }
}

这个示例代码使用Android提供的NsdManager类来发现局域网内的HTTP服务。在这个示例中，我们创建了一个`DiscoveryListener`实例，它实现了`onStartDiscoveryFailed`、`onStopDiscoveryFailed`、`onDiscoveryStarted`、`onDiscoveryStopped`、`onServiceFound`和`onServiceLost`方法，在服务被发现、丢失、启动和停止时调用。然后我们使用`NsdManager`的`discoverServices`方法来发现服务，并传入定义的`DiscoveryListener`实例。最后，在`onServiceFound`方法中，我们调用`resolveService`方法来解析服务，获取它的IP地址和端口号。