我不知道我的应用程序出了什么问题我跟着这么多教程，任何提示/帮助/建议都会受到赞赏，我是android的新手。我在listner的onserviceregistrationfailed函数中遇到错误。
package com.example.ravinetworkapplication;
import java.io.IOException;
import java.net.ServerSocket;
import java.security.PublicKey;
import java.util.ArrayList;
import java.util.List;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.content.Context;
import android.content.pm.ServiceInfo;
import android.net.nsd.NsdManager;
import android.net.nsd.NsdManager.DiscoveryListener;
import android.net.nsd.NsdServiceInfo;
import android.net.nsd.NsdManager.RegistrationListener;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.Toast;
import android.os.Build;
public class MainActivity extends ActionBarActivity {
NsdManager mNsdManager;
Context context;
NsdManager.DiscoveryListener mDiscoveryListner=null;
NsdManager.RegistrationListener mRegistrationListener=null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment()).commit();
}
mNsdManager= (NsdManager) this.getSystemService(Context.NSD_SERVICE);
final ServerSocket mServerSocket;
final ArrayList<String> listName = new ArrayList<String>();
Integer localPort = 0;
final ListView list = (ListView) findViewById(R.id.listView1);
listName.add("arunima");
listName.add("abhishek");
final ArrayAdapter<String> adapter = new ArrayAdapter<String>(this , android.R.layout.simple_list_item_1,listName);
list.setAdapter(adapter);
try {
mServerSocket = new ServerSocket(0);
localPort = mServerSocket.getLocalPort();
mServerSocket.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
mRegistrationListener = new NsdManager.RegistrationListener() {
@Override
public void onUnregistrationFailed(NsdServiceInfo serviceInfo, int errorCode) {
// TODO Auto-generated method stub
}
@Override
public void onServiceUnregistered(NsdServiceInfo serviceInfo) {
// TODO Auto-generated method stub
}
@Override
public void onServiceRegistered(NsdServiceInfo serviceInfo) {
// TODO Auto-generated method stub
Log.v("service registrd", "i am on folks");
Toast.makeText(getApplicationContext(), "Registerd", Toast.LENGTH_LONG).show();
}
@Override
public void onRegistrationFailed(NsdServiceInfo serviceInfo, int errorCode) {
// TODO Auto-generated method stub
Log.v("service registration fail", "can not register service kumar ravi");
}
};
mDiscoveryListner = new NsdManager.DiscoveryListener() {
@Override
public void onStopDiscoveryFailed(String serviceType, int errorCode) {
// TODO Auto-generated method stub
Log.v("cannot stop service", "service discovery failed");
}
@Override
public void onStartDiscoveryFailed(String serviceType, int errorCode) {
// TODO Auto-generated method stub
Log.v("can not start", "Can not start discovery kumar ravi "+errorCode);
}
@Override
public void onServiceLost(NsdServiceInfo service) {
// TODO Auto-generated method stub
}
@Override
public void onServiceFound(NsdServiceInfo service) {
// TODO Auto-generated method stub
Log.v("service found", "we found the service");
if(!service.getServiceType().equals("_myapp.tcp.")){
}
else if(service.getServiceName().equals("kumar")){
}
else {
listName.add(service.getServiceName());
adapter.notifyDataSetChanged();
list.setAdapter(adapter);
Toast.makeText(getApplicationContext(), "Finally found the service "+service.getServiceName(), Toast.LENGTH_LONG).show();
}
}
@Override
public void onDiscoveryStopped(String serviceType) {
// TODO Auto-generated method stub
}
@Override
public void onDiscoveryStarted(String serviceType) {
// TODO Auto-generated method stub
Log.v("Service Discovery Started", "Searching of Service Discovery");
}
};
Log.v("registerd port", localPort.toString());
final NsdServiceInfo serviceInfo = new NsdServiceInfo();
serviceInfo.setPort(localPort);
serviceInfo.setServiceName("kumar");
serviceInfo.setServiceType("_myapp.tcp.");
//mNsdManager.registerService(serviceInfo, NsdManager.PROTOCOL_DNS_SD, mRegistrationListener);
Button startBroadcast = (Button) findViewById(R.id.button1);
Button startListen = (Button) findViewById(R.id.button2);
startBroadcast.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
mNsdManager.registerService(serviceInfo, NsdManager.PROTOCOL_DNS_SD, mRegistrationListener);
}
});
startListen.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
mNsdManager.discoverServices("_myapp.tcp.", NsdManager.PROTOCOL_DNS_SD, mDiscoveryListner);
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
@Override
protected void onPause() {
// TODO Auto-generated method stub
super.onPause();
try{
mNsdManager.unregisterService(mRegistrationListener);
mNsdManager.stopServiceDiscovery(mDiscoveryListner);
Log.v("Stopped", "Scanning stopped"); }
catch(Exception e){
Log.v("some error in unregistring service", e.toString());
}
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container,
false);
return rootView;
}
}
}