Develop Reference

File not found: On WIFI is totally OK, but on 3G I have an exception

My android app is set for minSdkVersion="16" targetSdkVersion="17". I use the following code.
URL urlLinkSource = new URL("XXXX");
urlLinkSourceReader = new BufferedReader(new InputStreamReader(
urlLinkSource.openStream(), "UTF-8"));
ObjectMapper mapper = new ObjectMapper();
mapper.configure(
DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES,
false);
dataContainerListLightData = mapper.readValue(urlLinkSourceReader,
new TypeReference<List<DataContainerListLight>>() {
});
For reading my JSON data. The main problem is that everything is working fine when I use WIFI, when I switch only to 3G connection I have next exception:
03-14 14:06:22.349: W/System.err(7578): java.io.FileNotFoundException
In fact I have 2 JSON sources for processing. Is there some pool connection limit or other restrictions for pure 3G connection without WIFI? The exact place of my exception is urlLinkSource.openStream() (the logs are speaking it) and I tried on brawser and wifi test - all is working. What is the source of that exception in pure 3G mode?

Have you tried to open the url in the browser with 3G connection?
It seems that you want to implement a RESTful interface so I recomend you to use the DefaultHttpClient.
Here you can see how to implement such an interface:
How to get JSON content from a RESTful server to a Android client?

Complete CONNECTIVITY_SERVICE test

My application connects to the internet onCreate, it does this in an AsyncTaks class and all works fine. I have some error checking in place to make sure there is internet available and works great if I say put my phone on Flight Mode.
My problem is when I’m on WIFI, where I live the WWW drops out from time to time but the phone still thinks it’s connected. E.g.. the phone is still connected to the WIFI dongle but the WIFI dongle is not connected to the WWW, so when the application opens and tries to connect it gets an error and I get a force close.
How can I do a complete internet connection check onCreate that will cover all bases???
Cheers,
Mike.

One possibility is just to handle the error that you are getting in a better manner. You are getting a force close right now because (I assume) you are getting a RuntimeException from your application. Handling the exceptions and putting up proper messaging to your user might be adequate.
Another way is just make one (or a couple) connections to some high available servers to see if it works. For example, something like the following should work:
HttpClient client = new DefaultHttpClient();
HttpGet request = new HttpGet("http://www.google.com/");
try {
HttpResponse response = client.execute(request);
txtResult.setText(HttpHelper.request(response));
// internet is working
} catch(Exception ex) {
// internet is not working
txtResult.setText("Internet ENOWORK");
}
If you post the exception/error that you are getting and comment on my answer I can edit it with more specifics.

Consuming web service from a remote computer

I have a desktop application built with jdk 6 which publishes web services to be consumed by a web application. So far I've had no problem while both applications are running in the same physical computer, i can access the wsdl without any problem and the web application works with the desktop application just fine. The thing is I cannot access to the services from a remote computer in the same network. The two PCs are connected and can interact. If I run both applications in PC1, from PC2 I can use the webapp through
http://PC1:8080
I am currently publishing like this:
public Publicador(){
servicios= new Servicios();
Endpoint endpoint = Endpoint.publish("http://PC1:8686/servicios", servicios);
}
where PC1 is the name of the pc. From PC1, i can see the generated wsdl from the following address, and it's the one I used for the wsimport command:
http://PC1:8686/servicios?wsdl
But I cannnot from PC2.
Any ideas why it is not visible from outside PC1?

Incredible as it may seem, I found the simplest of answers... Instead of publishing as
Endpoint endpoint = Endpoint.publish("http://PC1:8686/servicios", servicios);
I published as
Endpoint endpoint = Endpoint.publish("http://0.0.0.0:8686/servicios", servicios);
and that solved it...
Another solution was to get the address to publish from a file, that worked too. I don't know why it didn't hardcoded... I ended up doing it like this:
Properties prop = new Properties();
InputStream is = null;
String currenDir = System.getProperty("user.dir");
String nombreArchivo = currenDir + File.separator + "ubicacion.PROPERTIES";
try {
is=new FileInputStream(nombreArchivo);
prop.load(is);
} catch(IOException ioe) {}
String pc = prop.getProperty("ServiciosWeb");
Endpoint endpoint = Endpoint.publish( pc, servicios);
}

How to control the handset using AT commands in java

I know that by using AT commands we can control the handset.As example unlocking screen we can give a specific AT command or moving right to the menu or left or bottom or up we can give specific AT commands. What all are the AT commands for doing this kind of control.
Thank you.

From what I understand, the AT commands are more used for phone-type functions (making calls, or sending SMS, etc), rather than menu navigation, etc.
I'm not entirely sure if that was your end-goal after menu navigation, but you can find more details here: http://en.wikipedia.org/wiki/Hayes_command_set (the original +AT command set)
If you wanted to send SMS from a handset connected to your computer you might want to take a peek at this page: http://www.developershome.com/sms/atCommandsIntro.asp
If you wanted more control when performing functions, like sending SMS, etc, you might want to investigate "PDU Mode."
It is entirely possible that some handset manufacturers may have implemented additional +AT commands to allow other functions to be performed, so you might do better by specifically searching for the commands related to the handset you are using.
(Of course, if you're having issues connecting to the handset hardware itself, you need to ensure you have either the javax.comm extension or some favoured Java USB API installed)
If post doesn't help, perhaps you could provide more details in your question? (eg. what you are ultimately trying to do, if you think it would help)

List of AT commands
sample java code to use AT command
public void servicesDiscovered(int transID, ServiceRecord serviceRecord[])
{
String url = serviceRecord[0].getConnectionURL(1, false);
try
{
//ClientSession conn= (ClientSession)Connector.open(url);
StreamConnection meineVerbindung = (StreamConnection) Connector.open(url);
if(conn== null)
System.out.println("Kann Service URL nicht oeffnen\n");
else
{
OutputStream out = conn.openOutputStream();
InputStream in = conn.openInputStream();
String message = "AT+CGMI\r\n";
// send AT-command
System.out.println("send AT Comand request: "+message);
out.write(message.getBytes());
out.flush();
out.close();
byte buffer[] = new byte[10000];
// read the response from mobile phone
in.read(buffer);
System.out.println("AT Comand response: "+buffer.toString());}
}
catch(IOException e)
{
System.out.println("Service Error(3): "+e.getMessage());
}
}

getContentLength doesn't work on android for FTP url

Following code prints length -1 for filesize on android, but it works fine on desktop JAVA.
I'm using Android 2.2.
URL url1 = null;
URLConnection uconn = null;
try {
url1 = new URL("ftp://FTPHOST/file.zip");
uconn = url1.openConnection();
uconn.setDoInput(true);
int len= uconn.getContentLength();
int headersize = uconn.getHeaderFields().size();
System.out.println("******************************* "+len);
} catch (Exception e) {
e.printStackTrace();
}
return null;
Let me know if any workaround in android to get filesize..

The Android platform's url connection code uses a different base (Apache HTTP client) under the hood, rather than the Oracle JVM's implementation. Apache HTTP client doesn't natively support FTP download the way the desktop JVM does.
The desktop JVM uses a class that was historically named sun.net.ftp.FtpClient for that FTP functionality. None of the sun classes are available on Android, so that doesn't work. You'll need to get your own FTP client.