I am trying to write simple socket program in blackberry, but it is not working. I have tried a lot. Please someone help me. Is any additional settings are required with simulator?
Thanks in advance :)
try
{
StreamConnection conn =(StreamConnection)Connector.open("socket://some ip:4444;deviceside=false,Connector.READ_WRITE,true");
OutputStreamWriter _out = new OutputStreamWriter(conn.openOutputStream());
String data = "This is a test\n";
int length = data.length();
_out.write(data, 0, length);
InputStreamReader _in = new InputStreamReader(conn.openInputStream());
char[] input = new char[length];
for ( int i = 0; i < length; ++i )
{
input[i] = (char)_in.read();
};
_in.close();
_out.close();
conn.close();
}
If you are trying to connect exactly how you have mentioned above then you indeed are not supposed to be able to connect:
StreamConnection conn =(StreamConnection)Connector.open("socket://some
ip:4444;deviceside=false,Connector.READ_WRITE,true")
because there was a wrongly placed quotation mark after the boolean value true, which should have been placed after ...deviceside=false, i.e. the correct StreamConnection should have formed somewhat like this:
StreamConnection conn =(StreamConnection)Connector.open("socket://some
ip:4444;deviceside=false",Connector.READ_WRITE,true);
The Connector.READ_WRITE and the boolean values are the parameters for the Connector.Open() method.
check the following link it may be help you
http://supportforums.blackberry.com/t5/Java-Development/Different-ways-to-make-an-HTTP-or-socket-connection/ta-p/445879
Related
When should I close an ObjectOutputStream using the following code? Thank you all...
try{
ObjectOutputStream output = new ObjectOutputStream(client.getOutputStream());
AnObject[] array = new AnObject[4];
for(int i = 0; i < array.length ; i++){
array[i] = new AnObject();
output.writeObject(array[i]);
}
output.flush();
output.close();
}
catch(IOException e){
processException();
}
Whenever you're done using it. You should flush() after sending, to force through all the data added to the stream's buffer to your underlying stream (Object*Streams are wrappers to your client's OutputStream), even if the stream's buffer isn't full.
Also, no need to flush before closing, because output.close() calls flush().
It looks like you close it after sending data, so unless you have more stuff to send through your client's stream, you're closing properly.
I saw the sample APIas below
public static byte[] compress( byte[] data )
{
try
{
ByteArrayOutputStream baos = new ByteArrayOutputStream();
GZIPOutputStream gzipStream = new GZIPOutputStream( baos, 6, GZIPOutputStream.MAX_LOG2_WINDOW_LENGTH );
gzipStream.write( data );
gzipStream.close();
}
catch(IOException ioe)
{
return null;
}
return baos.toByteArray();
}
But when I tried to compress with a large file with Curve 8900 OS 4.6, I got a "OutOfMemoryError" so I would like to know that how to compress as a chunk small data?
I already tried with this code as below but it doesn't work, compressed file cannot decompress...
file = (FileConnection)Connector.open(_fileOutputPath, Connector.READ_WRITE);
if (!file.exists()) {
file.create();
}
os = file.openOutputStream();
is = FileUtil.getInputStream(_fileInputPath, 0);
int tmpSize = 1024;
byte[] tmp = new byte[tmpSize];
int len = -1;
gzipStream = new GZIPOutputStream( os, 6, GZIPOutputStream.MAX_LOG2_WINDOW_LENGTH );
while((len = is.read(tmp, 0, tmpSize)) != -1) {
gzipStream.write(tmp, 0, len);
}
GZIPOutputStream does not produce a file suitable for use with the gzip command line tool. This is because it doesn't produce the necessary file headers. How did you test decompressing it? You should write a similar Java program that makes use of GZIPInputStream to test, as 'gunzip' is not going to recognize the input.
The problem of the first code sample is that the ByteArrayOutputStream is getting too big for the limited memory of a mobile device.
An option could be to first write to a file (for instance) on SD card.
The second code sample seems fine, but see Michael's answer.
From the simulator, this all works.
I'm using wifi on the device as i'm assuming it's the most stable.
The problem occurs when i try to post more than 1.5K of urlencoded data.
If i send less then it's fine.
It seems to hang the .flush command();
It works on a physical 9700, so i'm presuming that it's possibly device specific
In the example below i'm using form variables, but i've also tried posting the content type json, but still had the same issue
I've written a small testapp, and using the main thread so i know that it's not threads getting confused
If anyone has any ideas that would be great.
private String PostEventsTest()
{
String returnValue = "Error";
HttpConnection hc = null;
DataInputStream dis = null;
DataOutputStream dos = null;
StringBuffer messagebuffer = new StringBuffer();
URLEncodedPostData postValuePairs;
try
{
postValuePairs = new URLEncodedPostData(null, false);
postValuePairs.append("DATA",postData);// postData);
hc = (HttpConnection) Connector.open(postURL, Connector.READ_WRITE);
hc.setRequestMethod(HttpConnection.POST);
hc.setRequestProperty("User-Agent", "BlackBerry");
hc.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
hc.setRequestProperty("Content-Length", Integer.toString(postValuePairs.getBytes().length));
//hc.setRequestProperty("Content-Length", Integer.toString(postData.length()));
dos = hc.openDataOutputStream();
dos.write(postValuePairs.getBytes());
dos.flush();
dos.close();
// Retrieve the response back from the servlet
dis = new DataInputStream(hc.openInputStream());
int ch;
// Check the Content-Length first
long len = hc.getLength();
if (len != -1)
{
for (int i = 0; i < len; i++)
if ((ch = dis.read()) != -1)
messagebuffer.append((char) ch);
}
else
{ // if the content-length is not available
while ((ch = dis.read()) != -1)
messagebuffer.append((char) ch);
}
dis.close();
returnValue = "Yahoo";
}
catch (Exception ex)
{
returnValue = ex.toString();
ex.printStackTrace();
}
return returnValue;
}
Instead of data streams you should just use the regular input and output streams. So instead of hc.openDataOutputStream() use hc.openOutputStream(). Data streams are for serializing Java objects to a stream, but you just want to write the raw bytes to the stream -- so a regular outputstream is what you want. Same for reading the response - just use the inputstream returned by hc.openInputStream()
When reading the InputStream of an HttpURLConnection, is there any reason to use one of the following over the other? I've seen both used in examples.
Manual Buffer:
while ((length = inputStream.read(buffer)) > 0) {
os.write(buf, 0, ret);
}
BufferedInputStream
is = http.getInputStream();
bis = new BufferedInputStream(is);
ByteArrayBuffer baf = new ByteArrayBuffer(50);
int current = 0;
while ((current = bis.read()) != -1) {
baf.append(current);
}
EDIT I'm still new to HTTP in general but one consideration that comes to mind is that if I am using a persistent HTTP connection, I can't just read until the input stream is empty right? In that case, wouldn't I need to read the message length and just read the input stream for that length?
And similarly, if NOT using a persistent connection, is the code I included 100% good to go in terms of reading the stream properly?
I talk about a good way to do it on my blog in a post about using JSON in android. http://blog.andrewpearson.org/2010/07/android-why-to-use-json-and-how-to-use.html. I will post the relevant part of the relevant post below (the code is pretty generalizable):
InputStream in = null;
String queryResult = "";
try {
URL url = new URL(archiveQuery);
HttpURLConnection urlConn = (HttpURLConnection) url.openConnection();
HttpURLConnection httpConn = (HttpURLConnection) urlConn;
httpConn.setAllowUserInteraction(false);
httpConn.connect();
in = httpConn.getInputStream();
BufferedInputStream bis = new BufferedInputStream(in);
ByteArrayBuffer baf = new ByteArrayBuffer(50);
int read = 0;
int bufSize = 512;
byte[] buffer = new byte[bufSize];
while(true){
read = bis.read(buffer);
if(read==-1){
break;
}
baf.append(buffer, 0, read);
}
queryResult = new String(baf.toByteArray());
} catch (MalformedURLException e) {
// DEBUG
Log.e("DEBUG: ", e.toString());
} catch (IOException e) {
// DEBUG
Log.e("DEBUG: ", e.toString());
}
}
Regarding persistent HTTP connections it is just the opposite. You should read everything from the input stream. Otherwise the Java HTTP client does not know that the HTTP request is complete and the socket connection can be reused.
See http://java.sun.com/javase/6/docs/technotes/guides/net/http-keepalive.html:
What can you do to help with Keep-Alive?
Do not abandon a connection by
ignoring the response body. Doing so
may results in idle TCP connections.
That needs to be garbage collected
when they are no longer referenced.
If getInputStream() successfully
returns, read the entire response
body.
Use former -- latter has no real benefits over first one, and is bit slower; reading things byte by byte is inefficient even if buffered (although horribly slow when not buffered). That style of reading input went out of vogue with C; although may be useful in cases where you need to find an end marker of some sort.
Only if you're using the BufferedInputStream-specific methods.
I'm working on a .NET WinForms app that needs to print a FEDEX shipping label. As part of the FedEx api, I can get raw label data for the printer.
I just don't know how to send that data to the printer through .NET (I'm using C#). To be clear, the data is already pre formatted into ZPL (Zebra printer language) I just need to send it to the printer without windows mucking it up.
C# doesn't support raw printing, you'll have to use the win32 spooler, as detailed in this KB article How to send raw data to a printer by using Visual C# .NET.
Hope this helps.
-Adam
I think you just want to send the ZPL (job below) directly to your printer.
private void SendPrintJob(string job)
{
TcpClient client = null;
NetworkStream ns = null;
byte[] bytes;
int bytesRead;
IPEndPoint remoteIP;
Socket sock = null;
try
{
remoteIP = new IPEndPoint( IPAddress.Parse(hostName), portNum );
sock = new Socket(AddressFamily.InterNetwork,
SocketType.Stream,
ProtocolType.Tcp);
sock.Connect(remoteIP);
ns = new NetworkStream(sock);
if (ns.DataAvailable)
{
bytes = new byte[client.ReceiveBufferSize];
bytesRead = ns.Read(bytes, 0, bytes.Length);
}
byte[] toSend = Encoding.ASCII.GetBytes(job);
ns.Write(toSend, 0, toSend.Length);
if (ns.DataAvailable)
{
bytes = new byte[client.ReceiveBufferSize];
bytesRead = ns.Read(bytes, 0, bytes.Length);
}
}
finally
{
if( ns != null )
ns.Close();
if( sock != null && sock.Connected )
sock.Close();
if (client != null)
client.Close();
}
}
A little late, but you can use this CodePlex Project for easy ZPL printing
http://sharpzebra.codeplex.com/
Zebra printers don't use a spooler, it isn't raw printing. It's a markup called ZPL. It's text based, not binary.
I've been working with a printer and ZPL for a while now, but with a Ruby app. Sending the ZPL out to the printer via socket works fine.
To check that it works, I often telnet to the printer and type ^XA^PH^XZ to feed a single label. Hope that helps.