How to check Interconnection is available or not in j2me(Lwuit) - java-me

In my app I want to check gprsconnection using dialog in j2me(lwuit) can anyone have idea?

Simply try to open an address
private boolean isNetworkAvailable() {
boolean result = false;
HttpConnection httpConnection = null;
try {
httpConnection = (HttpConnection) Connector.open("http://www.google.com");
result = true;
} catch (Exception e) {
}
return result;
}

Related

Async call never returns

please have a look at below code.
public static class DbModel
{
public static readonly int TableID = 0;
static DbModel()
{
DbModel.PodID = FetchTableID().PodID;
}
public static Pod FetchTableID()
{
Pod result = null;
try
{
//Control never comes back from this line. What am I missing?
var searchResult = apiPod.SearchTableAsync(1).Result;
result = searchResult.First();
}
catch (Exception ex)
{
Helpers.TraceException(PageName,"FEtchPodID","Unable to fetch PodID",ex);
}
return result;
}
}
Signature of SearchTableAsync looks like this
public async Task<List<Pod>> SearchTableAsync(int i)
{
try
{
using (var client = new HttpClient())
{
//deleted - connecting to server, constructing query string etc.
var response = await client.GetAsync(ApiBaseUrl + "api/Pod/Search" + queryString);
if (response.IsSuccessStatusCode)
{
var podList = await response.Content.ReadAsAsync<List<Pod>>();
return podList;
}
else
{
//log error
}
}
}
catch (Exception ex)
{
Logger.TraceError(null, ex);
}
return null;
}
Call to SearchTableAsync never returns back. Am I missing anything? Or its because I am invoking this from Static constructor?
The problem is likely due to the use of Task.Result property. this is a blocking property and can cause a deadlock. You can simply await the task which will return the result, but you need to make the method async.
public static async Pod FetchTableID()
{
Pod result = null;
try
{
var searchResult = await apiPod.SearchTableAsync(1);
result = searchResult.First();
}
catch (Exception ex)
{
Helpers.TraceException(PageName,"FEtchPodID","Unable to fetch PodID",ex);
}
return result;
}
searchResult = apiPod.SearchTableAsync(1).excute.get;
use this instead of
var searchResult = apiPod.SearchTableAsync(1).Result;
This post explains why it was blocking.
Cheers,
Hemant

Download Images in loop java me

In my application we have to download around 10 Images from server and display it in mobile. How can I do this? Can I use same HttpConnection for full download? Is any other way for download?
You can do with this simple loop (Supposing imageList is a List with the url of the images).
HttpConnection = null;
Image image = null;
for (int i = 0; i < imageList.getSize(); i++) {
try{
String urlImage = imageList.get(i);
hc = (HttpConnection) Connector.open(urlImage);
image = Image.createImage(hc.openInputStream()));
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
hc.close();
} catch (IOException ex) {
ex.printStackTrace();
}
}
}
You can try following method in a loop for downloading images from server.
private void downloadImage ( String URL )
{
try
{
System.out.println("URL FOR POST_DATA : "+URL);
// Open up a http connection with the Web server for both send and receive operations
httpConnection = (HttpConnection)Connector.open(URL, Connector.READ_WRITE);
// Set the request method to POST
httpConnection.setRequestMethod(HttpConnection.POST);
// Set the request headers
httpConnection.setRequestProperty(ConstantCodes.ACTION_MODE_PARAMETER,action);
httpConnection.setRequestProperty(ConstantCodes.USER_NAME_REQUEST_PARAMETER,userName);
if(eventName==null || eventName.equals(""))
eventName="default";
httpConnection.setRequestProperty(ConstantCodes.EVENT_NAME_REQUEST_PARAMETER, eventName);
httpConnection.setRequestProperty(ConstantCodes.CAMERAID_REQUEST_PARAMETER, cameraID);
// all the headers are sending now and connection chanel is establising
dis = httpConnection.openDataInputStream();
int ch = 0;
ByteArrayOutputStream bytearray = new ByteArrayOutputStream(250000);
while((ch = dis.read()) != -1)
bytearray.write(ch);
// fileByte contains whole file in bytes
byte fileByte[] = bytearray.toByteArray();
fileSize = fileByte.length;
System.out.println("Got file size : "+fileSize);
if(bytearray!=null) bytearray.close();
midlet.getLastPostedImageResponse(fileByte);
}
catch (IOException ioe)
{
ioe.printStackTrace();
System.out.println("IOException occured during getting last image data : "+ioe.getMessage());
}
catch(Exception e)
{
e.printStackTrace();
System.out.println("Eeception occurred during getting last image data : "+e.getMessage());
}
finally
{
System.out.println("Calling close from Last image posted Action");
close();
}

save data from servlet to recordstore in j2me

I am developing an j2me application which is communicating with the database using servlet.
I want to store the data received from servlet into record store and display it.how this can be achieved?Please provide code examples.
Thank you in advance
public void viewcon()
{
StringBuffer sb = new StringBuffer();
try {
HttpConnection c = (HttpConnection) Connector.open(url);
c.setRequestProperty("User-Agent","Profile/MIDP-1.0, Configuration/CLDC-1.0");
c.setRequestProperty("Content-Language","en-US");
c.setRequestMethod(HttpConnection.POST);
DataOutputStream os = (DataOutputStream)c.openDataOutputStream();
os.flush();
os.close();
// Get the response from the servlet page.
DataInputStream is =(DataInputStream)c.openDataInputStream();
//is = c.openInputStream();
int ch;
sb = new StringBuffer();
while ((ch = is.read()) != -1) {
sb.append((char)ch);
}
// return sb;
showAlert(sb.toString());//display data received from servlet
is.close();
c.close();
} catch (Exception e) {
showAlert(e.getMessage());
}
}
Put this function call where you show the response data alert
writeToRecordStore(sb.toString().getBytes());
The function definition is as below:
private static String RMS_NAME = "NETWORK-DATA-STORAGE";
private boolean writeToRecordStore(byte[] inStream) {
RecordStore rs = null;
try {
rs = RecordStore.openRecordStore(RMS_NAME, true);
if (null != rs) {
//Based on your logic either ADD or SET the record
rs.addRecord(inStream, 0, inStream.length);
return true;
} else {
return false;
}
} catch (RecordStoreException ex) {
ex.printStackTrace();
return false;
} finally {
try {
if (null != rs) {
rs.closeRecordStore();
}
} catch (RecordStoreException recordStoreException) {
} finally {
rs = null;
}
}
}
After you have saved the data, read the records store RMS-NAME and check the added index to get the response data.
.
NOTE: The assumption is the network response data is to be appended to the record store. If you want to set it to a particular record modify the method writeToRecordStore(...) accordingly.
//this code throws exception in display class.
try
{
byte[] byteInputData = new byte[5];
int length = 0;
// access all records present in record store
for (int x = 1; x <= rs.getNumRecords(); x++)
{
if (rs.getRecordSize(x) > byteInputData.length)
{
byteInputData = new byte[rs.getRecordSize(x)];
}
length = rs.getRecord(x, byteInputData, 0);
}
alert =new Alert("reading",new String(byteInputData,0,length),null,AlertType.WARNING);
alert.setTimeout(Alert.FOREVER);
display.setCurrent(alert);
}

How to post data to server in J2ME? Getting response from server Invalid API Key

I am posting some data to server but i am getting {"status":false,"error":"Invalid API Key."} response from server. My API Key is correct but where is the problem i don't know. Please friends help me. I tried lot but i did not find solution. I have used following code for posting data to server.
public void tryingOne(String dtl){
HttpConnection httpConn = null;
InputStream is = null;
OutputStream os = null;
String url="http://api.geanly.in/ma/index?API-Key="+apikey;
String details = "&orderInfo={\"booking\":{\"restaurantinfo\":{\"id\":\"5722\"},\"referrer\":{\"id\": \"9448476530\" }, \"bookingdetails\":{\"instructions\":\"Make the stuff spicy\",\"bookingtime\": \"2011-11-09 12:12 pm\", \"num_guests\": \"5\"}, \"customerinfo\":{\"name\":\"Vinodh SS\", \"mobile\":\"9345245530\", \"email\": \"vind#gmail.com\", \"landline\":{ \"number\":\"0908998393\",\"ext\":\"456\"}}}}";
try {
System.out.println("url####"+url);
httpConn = (HttpConnection) Connector.open(url);
httpConn.setRequestMethod(HttpConnection.POST);
DataOutputStream outStream = new DataOutputStream(httpConn.openDataOutputStream());
outStream.write(details.getBytes(),0,details.length());
outStream.flush();
outStream.close();
//Reading Resp. from server
StringBuffer sb = new StringBuffer();
is = httpConn.openDataInputStream();
int chr;
while ((chr = is.read()) != -1) {
sb.append((char) chr);
}
System.out.println("Response from srvr " + sb.toString());
} catch (IOException ex) {
ex.printStackTrace();
} finally {
if (is != null) {
try {
is.close();
} catch (IOException ex) {
ex.printStackTrace();
}
}
if (os != null) {
try {
os.close();
} catch (IOException ex) {
ex.printStackTrace();
}
}
if (httpConn != null) {
try {
httpConn.close();
} catch (IOException ex) {
ex.printStackTrace();
}
}
}
}
Please help me friends...
Thanks
you need to trim the variable "apikey".
I was getting same problem when connecting with Picasa Server.
For sending data using HttpConnection use the class in this tutorial. It also gets the response from the server.

Reading a file in Blackberry

I am trying to read content from file in blackberry and i read the file content to result object and when i am trying to print the result object it gives error and the file is in res folder,and this is code that i got problem
private String readTextFile(String fName) {
String result = null;
FileConnection fconn = null;
DataInputStream is = null;
try {
fconn = (FileConnection) Connector.open(fName, Connector.READ_WRITE);
is = fconn.openDataInputStream();
byte[] data = IOUtilities.streamToBytes(is);
result = new String(data);
System.out.println("result data is ...... "+result);
} catch (IOException e) {
System.out.println(e.getMessage());
} finally {
try {
if (null != is)
is.close();
if (null != fconn)
fconn.close();
} catch (IOException e) {
System.out.println(e.getMessage());
}
}
return result;
}
what is fName here ?
The file name or the path could cause similar problem.

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