Android Eclipse中使用JmDNS的服务发现：Wifistatemachine错误
我的代码工作了，但它不会突然工作。代码如下Android Eclipse中使用JmDNS的服务发现：Wifistatemachine错误,android,eclipse,jmdns,Android,Eclipse,Jmdns,我的代码工作了，但它不会突然工作。代码如下 public class AndroidDnssdDiscoveryTestActivity extends Activity { /** Called when the activity is first created. */ android.net.wifi.WifiManager.MulticastLock lock; android.os.Handler handler = new android.os.Handler(); final C
public class AndroidDnssdDiscoveryTestActivity extends Activity {
/** Called when the activity is first created. */
android.net.wifi.WifiManager.MulticastLock lock;
android.os.Handler handler = new android.os.Handler();
final Context context = this;
AlertDialog alert=null;
public void onCreate(Bundle savedInstanceState) {
/*
* StrictMode.ThreadPolicy was introduced since API Level 9 and the default thread policy had been changed since API Level 11,
* which in short, does not allow network operation (include HttpClient and HttpUrlConnection) get executed on UI thread.
* if you do this, you get NetworkOnMainThreadException. It needs to add the following 3 lines.
*/
if (android.os.Build.VERSION.SDK_INT > 9) {
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
}
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
handler.postDelayed(new Runnable() {
public void run() {
setUp();
}
}, 1000);
}
private String type = "_http._tcp.local.";
private JmDNS jmdns = null;
private String Servername ="test._http._tcp.local.";
private boolean _findSECE = false;
private ServiceListener listener = null;
private HttpClient httpclient = new DefaultHttpClient();
private ServiceInfo serviceInfo;
//private ServiceInfo serviceInfo;
private void setUp() {
android.net.wifi.WifiManager wifi = (android.net.wifi.WifiManager) getSystemService(android.content.Context.WIFI_SERVICE);
lock = wifi.createMulticastLock("mylockthereturn");
lock.setReferenceCounted(true);
lock.acquire();
try {
jmdns = JmDNS.create();
notifyUser("create");
jmdns.addServiceListener(type, listener = new ServiceListener() {
public void serviceResolved(ServiceEvent ev) {
final String getName = ev.getInfo().getQualifiedName();
final String getUrl = ev.getInfo().getURLs()[0];
if(getName.equalsIgnoreCase(servername))
{
Log.d("getName",getName);
Log.d("getUrl",getUrl);
// show alert
((Activity) context).runOnUiThread(new Runnable() {
public void run() {
alertDialog(getName,getUrl);
}
});
}else{
notifyUser("Name: " + getName+"\nURL: " + getUrl);
Log.d("getName",getName);
Log.d("getUrl",getUrl);
}
}
public void serviceRemoved(ServiceEvent ev) {
notifyUser("Service removed: " + ev.getName());
}
public void serviceAdded(ServiceEvent event) {
// Required to force serviceResolved to be called again (after the first search)
jmdns.requestServiceInfo(event.getType(), event.getName(), 1);
}
});
serviceInfo = ServiceInfo.create("_http._tcp.local.", "AndroidTest", 0, "plain test service from android");
jmdns.registerService(serviceInfo);
} catch (IOException e) {
e.printStackTrace();
return;
}
}
public void alertDialog(final String getName, final String getUrl){
AlertDialog.Builder builder = new AlertDialog.Builder(context);
builder.setMessage("SECE service found! Do you want to control the light?")
.setCancelable(false)
.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
Log.d("ACTION","BUTTON Pressed");
SendHttpPost(getName,getUrl);
}
})
.setNegativeButton("No", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
dialog.cancel();
}
});
alert = builder.create();
alert.show();
}
private void SendHttpPost(String getName, String getUrl){
HttpGet httpget = new HttpGet(getUrl);
try {
HttpResponse response = httpclient.execute(httpget);
HttpEntity entity = response.getEntity();
byte buffer[] = new byte[1024] ;
InputStream is = entity.getContent() ;
int numBytes = is.read(buffer) ;
is.close();
String entityContents = new String(buffer,0,numBytes) ;
Log.d("getName",getName);
Log.d("getUrl",getUrl);
Log.d("replay",entityContents);
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
private void notifyUser(final String msg) {
handler.postDelayed(new Runnable() {
public void run() {
TextView t = (TextView)findViewById(R.id.text);
t.setText("\n===========\n"+t.getText());
t.setText(msg+t.getText());
}
}, 1);
}
@Override
protected void onStart() {
super.onStart();
}
@Override
protected void onStop() {
if (jmdns != null) {
if (listener != null) {
jmdns.removeServiceListener(type, listener);
listener = null;
}
jmdns.unregisterAllServices();
try {
jmdns.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
jmdns = null;
}
lock.release();
super.onStop();
}
你有什么想法吗？你可以尝试再次检查你的网络
权限是否消失/更改
android.permission.ACCESS_NETWORK_STATE
android.permission.ACCESS_WIFI_STATE
android.permission.INTERNET
android.permission.CHANGE_WIFI_MULTICAST_STATE