I am trying to write a program using chronicle map. I have written a UDP server which will broadcast a message every 1 sec. A UDP client will receive the message and will store the message in a chronicle map. The programs are as under:
The UDP server program:
public class UDPServer {
public static void main(String[] args) {
DatagramSocket socket = null;
try {
socket = new DatagramSocket();
byte[] buf = new byte[256];
String messg = "Hello UDP Server\n";
String transmittedMsg = null;
int count = 0;
while (true) {
transmittedMsg = count + "";
buf = transmittedMsg.getBytes();
InetAddress address = InetAddress.getByName ("127.0.0.1");
DatagramPacket packet = new DatagramPacket (buf, buf.length, address, 4000);
socket.send(packet);
Thread.sleep(1000);
count++;
}
} catch (SocketTimeoutException ex) {
System.out.println("Timeout error: " + ex.getMessage());
ex.printStackTrace();
} catch (IOException ex) {
System.out.println("Client error: " + ex.getMessage());
ex.printStackTrace();
} catch (InterruptedException ex) {
ex.printStackTrace();
} finally {
socket.close();
}
}
}
The UDP client program:
public class UDPClient {
public static void main(String[] args) {
DatagramSocket socket = null;
DatagramPacket packet = null;
byte[] buf = new byte[256];
ChronicleMap<String, String> cr = null;
try {
socket = new DatagramSocket(4000);
InetAddress address = InetAddress.getByName ("127.0.0.1");
while (true) {
packet = new DatagramPacket(buf, buf.length, address, 5000);
socket.receive(packet);
String received = new String(packet.getData());
System.out.println(received);
cr = ChronicleMapBuilder.of(String.class, String.class)
.name("test-map")
.averageKey("Message")
.averageValue("0")
.entries(1)
.actualChunkSize(100)
.actualSegments(1)
.createPersistedTo(new File("D://test.txt"));
cr.put("Message", received);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
if (cr != null) {
cr.close();
}
}
}
}
Below is the exception I am geting:
java.lang.IllegalArgumentException: ChronicleMap{name=test-map, file=D:\test.txt, identityHashCode=11583403}: Entry is too large: requires 68 chunks, 9 is maximum.
at net.openhft.chronicle.map.impl.CompiledMapQueryContext.allocReturnCode(CompiledMapQueryContext.java:1805)
at net.openhft.chronicle.map.impl.CompiledMapQueryContext.allocReturnCodeGuarded(CompiledMapQueryContext.java:123)
at net.openhft.chronicle.map.impl.CompiledMapQueryContext.alloc(CompiledMapQueryContext.java:3468)
at net.openhft.chronicle.map.impl.CompiledMapQueryContext.initEntryAndKey(CompiledMapQueryContext.java:3502)
at net.openhft.chronicle.map.impl.CompiledMapQueryContext.putEntry(CompiledMapQueryContext.java:3995)
at net.openhft.chronicle.map.impl.CompiledMapQueryContext.doInsert(CompiledMapQueryContext.java:4184)
at net.openhft.chronicle.map.MapEntryOperations.insert(MapEntryOperations.java:153)
at net.openhft.chronicle.map.impl.CompiledMapQueryContext.insert(CompiledMapQueryContext.java:4107)
at net.openhft.chronicle.map.MapMethods.put(MapMethods.java:88)
at net.openhft.chronicle.map.VanillaChronicleMap.put(VanillaChronicleMap.java:724)
at udp.client.UDPClient.main(UDPClient.java:38)
Please help.
Apparently, some entry that you receive is much larger than
averageKey("Message")
averageValue("0")
That you specified.
You also mix together high-level configurations: averageKey(), averageValue(), entries(), and low-level ones: actualChunkSize(), actualSegments(), that is not recommended.
Related
I'm doing a static code analysis using checkmarx, which gave me medium vulnerabilities for #RequestBody.
Will place a sample code below, could someone help me fixing this issue.
#RestController
#RequestMapping("/api")
#Slf4j
#Validated
public class Myclass {
#Autowired
SplitClass split;
#PostMapping(path = "/something", consumes = "application/json", produces = "application/json")
public int splitter(#RequestBody SplitRequestVO **splitReq**) {
int response = 0;
try {
int value = split.methodName(splitReq);
if(value == 1) {
response = 1;
}else {
response = 0;
}
}catch(Exception e) {
log.error("Excpetion in the MY Class controller" +e.getMessage());
}
return response;
}
}
Every time it is showing error with this util class. please check whats wrong in this class.
#Slf4j
public class FileUtil {
private FileUtil() {
throw new IllegalArgumentException("FileUtil.class");
}
public static void createFileFromBytes(String fileName, byte[] bytes) throws IOException {
File file = new File(fileName);
try (FileOutputStream fos = new FileOutputStream(file)) {
fos.write(bytes);
fos.flush();
} catch (IOException exc) {
log.error("Exception in creating file from bytes : "+exc.getMessage());
}
}
public static void deleteFile(String fileName) {
log.info("Entry into deleteFile method.");
try {
File file = new File(fileName);
if (file.exists()) {
Files.delete(file.toPath());
if (log.isDebugEnabled())
log.debug("file deleted:" + fileName);
}
} catch (Exception e) {
log.error("Exception in deleting the file : "+e.getMessage());
}
log.info("Exit from deleteFile method ");
}
public static byte[] getBytesFromFile(File file) throws IOException {
log.info("Entry into getBytesFromFile method");
byte[] bytes = null;
try (InputStream is = new FileInputStream(file)) {
long length = file.length();
if (length > 2147483647L) {
log.error("File Too large:" + file.getName());
}
bytes = new byte[(int) length];
int offset = 0;
int numRead = 0;
while (offset < bytes.length && (numRead = is.read(bytes, offset, bytes.length - offset)) >= 0)
offset += numRead;
if (offset < bytes.length)
throw new IOException("Could not completely read file " + file.getName());
} catch (Exception e) {
log.error("Exception in getBytesFromFile : "+e.getMessage());
}
log.info("Exit from getBytesFromFile method ");
return bytes;
}
public static byte[] getBytesFromFile(String fileName) throws IOException {
File file = new File(fileName);
return getBytesFromFile(file);
}
}
Here im facing the vulnerability issue to fix in the block letters. Appreciated foy help.
Thanks in advance.
I'm implementing a mail Sender, near 1'6000.000 mails (with images and PDF) in one day per month (closing month extract), the mails are about 12 products...
I need to fill a Message Scratch per product... in order to not read (per email) else per product.
I'm trying to implement cloning javax.mail.Message and javax.mail.Multipart in order to be faster.
AddContent to Multipart
public static void addContent(final Multipart multipart, String contenidoCorreo) throws Exception {
MimeBodyPart mimeBodyPart = new PreencodedMimeBodyPart("8bit");
mimeBodyPart.setText(contenidoCorreo, "iso-8859-1", "html");
multipart.addBodyPart(mimeBodyPart, 0);
}
Add Image per Bytes
public static void addImageToMultipart(final Multipart multipart, byte[] contenidoImagen, String nombreImagen) throws Exception {
MimeBodyPart imagenMimeBodyPart = new MimeBodyPart();
try {
ByteArrayDataSource byteArrayDataSource = new ByteArrayDataSource(contenidoImagen, "image/*");
imagenMimeBodyPart.setDataHandler(new DataHandler(byteArrayDataSource));
imagenMimeBodyPart.setFileName(nombreImagen);
imagenMimeBodyPart.setContentID("<" + nombreImagen + ">");
imagenMimeBodyPart.setDisposition(MimeBodyPart.INLINE);
multipart.addBodyPart(imagenMimeBodyPart);
} catch (Exception e) {
e.printStackTrace();
throw new RuntimeException(e.getMessage());
}
}
AddPDF per File
public static void addPDF(final Multipart multipart, String ruta, String nombre) throws Exception {
Path path = Paths.get(ruta, nombre);
if (path.toFile().exists()) {
MimeBodyPart preencodedMimeBodyPart = new PreencodedMimeBodyPart("base64");
preencodedMimeBodyPart.attachFile(path.toFile());
preencodedMimeBodyPart.setFileName(nombre);
preencodedMimeBodyPart.setHeader("Content-Type", "application/pdf");
preencodedMimeBodyPart.setDisposition(MimeBodyPart.ATTACHMENT);
multipart.addBodyPart(preencodedMimeBodyPart);
MimeBodyPart pdfMimeBodyPart = new MimeBodyPart();
}
My Cloning Message
public static Message cloneMessage(Message source) {
//Multiple and Separated Exceptions because maybe not all properties are defined in some time.
Message target = new MimeMessage(source.getSession());
try {
if (source.getFrom() != null && source.getFrom().length > 0) {
Address address = (source.getFrom()[0]);
target.setFrom(new InternetAddress(((InternetAddress) address).getAddress(), ((InternetAddress) address).getPersonal()));
}
} catch (Exception ex) {
//Handle Exception
}
try {
target.setSentDate((Date) (source.getSentDate().clone()));
} catch (MessagingException ex) {
//Handle Exception
}
try {
target.setRecipients(Message.RecipientType.TO, target.getRecipients(Message.RecipientType.TO).clone());
} catch (MessagingException ex) {
//Handle Exception
}
try {
Enumeration numerationHeaders = source.getAllHeaders();
while (numerationHeaders.hasMoreElements()) {
Header header = (Header) numerationHeaders.nextElement();
target.addHeader(header.getName(), header.getValue());
}
} catch (MessagingException ex) {
//Handle Exception
}
try {
target.setSubject(new String(source.getSubject()));
} catch (MessagingException ex) {
//Handle Exception
}
try {
target.setContent(cloneMultipart((Multipart)(source.getContent())));
} catch (Exception ex) {
//Handle Exception
}
return target;
}
Cloning Multipart
public static Multipart cloneMultipart(Multipart source) {
MimeMultipart target = new MimeMultipart();
try {
for (int i = 0; i < source.getCount(); i++) {
MimeBodyPart mimeBodyPart = (MimeBodyPart)source.getBodyPart(i);
mimeBodyPart //?????
}
} catch (MessagingException ex) {
//Handle Exception
}
return target;
}
How cloning Multipart?
some advice to clone Message?
How detect the Content (the used with addContent method) has been added?
I have wasted several hours trying to solve a issue with the use of netty's channel pool map and a jax rs client.
I have used jersey's own netty connector as an inspiration but exchanged netty's channel with netty's channel pool map.
https://jersey.github.io/apidocs/2.27/jersey/org/glassfish/jersey/netty/connector/NettyConnectorProvider.html
My problem is that I have references that I need inside my custom SimpleChannelInboundHandler. However by the design of netty's way to create a channel pool map, I can not pass the references through my custom ChannelPoolHandler, because as soon as the pool map has created a pool the constructor of the channel pool handler never runs again.
This is the method where it makes acquires a pool and check out a channel to make a HTTP request.
#Override
public Future<?> apply(ClientRequest request, AsyncConnectorCallback callback) {
final CompletableFuture<Object> completableFuture = new CompletableFuture<>();
try{
HttpRequest httpRequest = buildHttpRequest(request);
// guard against prematurely closed channel
final GenericFutureListener<io.netty.util.concurrent.Future<? super Void>> closeListener =
future -> {
if (!completableFuture.isDone()) {
completableFuture.completeExceptionally(new IOException("Channel closed."));
}
};
try {
ClientRequestDTO clientRequestDTO = new ClientRequestDTO(NettyChannelPoolConnector.this, request, completableFuture, callback);
dtoMap.putIfAbsent(request.getUri(), clientRequestDTO);
// Retrieves a channel pool for the given host
FixedChannelPool pool = this.poolMap.get(clientRequestDTO);
// Acquire a new channel from the pool
io.netty.util.concurrent.Future<Channel> f = pool.acquire();
f.addListener((FutureListener<Channel>) futureWrite -> {
//Succeeded with acquiring a channel
if (futureWrite.isSuccess()) {
Channel channel = futureWrite.getNow();
channel.closeFuture().addListener(closeListener);
try {
if(request.hasEntity()) {
channel.writeAndFlush(httpRequest);
final JerseyChunkedInput jerseyChunkedInput = new JerseyChunkedInput(channel);
request.setStreamProvider(contentLength -> jerseyChunkedInput);
if(HttpUtil.isTransferEncodingChunked(httpRequest)) {
channel.write(jerseyChunkedInput);
} else {
channel.write(jerseyChunkedInput);
}
executorService.execute(() -> {
channel.closeFuture().removeListener(closeListener);
try {
request.writeEntity();
} catch (IOException ex) {
callback.failure(ex);
completableFuture.completeExceptionally(ex);
}
});
channel.flush();
} else {
channel.closeFuture().removeListener(closeListener);
channel.writeAndFlush(httpRequest);
}
} catch (Exception ex) {
System.err.println("Failed to sync and flush http request" + ex.getLocalizedMessage());
}
pool.release(channel);
}
});
} catch (NullPointerException ex) {
System.err.println("Failed to acquire socket from pool " + ex.getLocalizedMessage());
}
} catch (Exception ex) {
completableFuture.completeExceptionally(ex);
return completableFuture;
}
return completableFuture;
}
This is my ChannelPoolHandler
public class SimpleChannelPoolHandler implements ChannelPoolHandler {
private ClientRequestDTO clientRequestDTO;
private boolean ssl;
private URI uri;
private int port;
SimpleChannelPoolHandler(URI uri) {
this.uri = uri;
if(uri != null) {
this.port = uri.getPort() != -1 ? uri.getPort() : "https".equals(uri.getScheme()) ? 443 : 80;
ssl = "https".equalsIgnoreCase(uri.getScheme());
}
}
#Override
public void channelReleased(Channel ch) throws Exception {
System.out.println("Channel released: " + ch.toString());
}
#Override
public void channelAcquired(Channel ch) throws Exception {
System.out.println("Channel acquired: " + ch.toString());
}
#Override
public void channelCreated(Channel ch) throws Exception {
System.out.println("Channel created: " + ch.toString());
int readTimeout = Integer.parseInt(ApplicationEnvironment.getInstance().get("READ_TIMEOUT"));
SocketChannelConfig channelConfig = (SocketChannelConfig) ch.config();
channelConfig.setConnectTimeoutMillis(2000);
ChannelPipeline channelPipeline = ch.pipeline();
if(ssl) {
SslContext sslContext = SslContextBuilder.forClient().trustManager(InsecureTrustManagerFactory.INSTANCE).build();
channelPipeline.addLast("ssl", sslContext.newHandler(ch.alloc(), uri.getHost(), this.port));
}
channelPipeline.addLast("client codec", new HttpClientCodec());
channelPipeline.addLast("chunked content writer",new ChunkedWriteHandler());
channelPipeline.addLast("content decompressor", new HttpContentDecompressor());
channelPipeline.addLast("read timeout", new ReadTimeoutHandler(readTimeout, TimeUnit.MILLISECONDS));
channelPipeline.addLast("business logic", new JerseyNettyClientHandler(this.uri));
}
}
And this is my SimpleInboundHandler
public class JerseyNettyClientHandler extends SimpleChannelInboundHandler<HttpObject> {
private final NettyChannelPoolConnector nettyChannelPoolConnector;
private final LinkedBlockingDeque<InputStream> isList = new LinkedBlockingDeque<>();
private final AsyncConnectorCallback asyncConnectorCallback;
private final ClientRequest jerseyRequest;
private final CompletableFuture future;
public JerseyNettyClientHandler(ClientRequestDto clientRequestDTO) {
this.nettyChannelPoolConnector = clientRequestDTO.getNettyChannelPoolConnector();
ClientRequestDTO cdto = clientRequestDTO.getNettyChannelPoolConnector().getDtoMap().get(clientRequestDTO.getClientRequest());
this.asyncConnectorCallback = cdto.getCallback();
this.jerseyRequest = cdto.getClientRequest();
this.future = cdto.getFuture();
}
#Override
protected void channelRead0(ChannelHandlerContext ctx, HttpObject msg) throws Exception {
if(msg instanceof HttpResponse) {
final HttpResponse httpResponse = (HttpResponse) msg;
final ClientResponse response = new ClientResponse(new Response.StatusType() {
#Override
public int getStatusCode() {
return httpResponse.status().code();
}
#Override
public Response.Status.Family getFamily() {
return Response.Status.Family.familyOf(httpResponse.status().code());
}
#Override
public String getReasonPhrase() {
return httpResponse.status().reasonPhrase();
}
}, jerseyRequest);
for (Map.Entry<String, String> entry : httpResponse.headers().entries()) {
response.getHeaders().add(entry.getKey(), entry.getValue());
}
if((httpResponse.headers().contains(HttpHeaderNames.CONTENT_LENGTH) && HttpUtil.getContentLength(httpResponse) > 0) || HttpUtil.isTransferEncodingChunked(httpResponse)) {
ctx.channel().closeFuture().addListener(future -> isList.add(NettyInputStream.END_OF_INPUT_ERROR));
response.setEntityStream(new NettyInputStream(isList));
} else {
response.setEntityStream(new InputStream() {
#Override
public int read() {
return -1;
}
});
}
if(asyncConnectorCallback != null) {
nettyChannelPoolConnector.executorService.execute(() -> {
asyncConnectorCallback.response(response);
future.complete(response);
});
}
}
if(msg instanceof HttpContent) {
HttpContent content = (HttpContent) msg;
ByteBuf byteContent = content.content();
if(byteContent.isReadable()) {
byte[] bytes = new byte[byteContent.readableBytes()];
byteContent.getBytes(byteContent.readerIndex(), bytes);
isList.add(new ByteArrayInputStream(bytes));
}
}
if(msg instanceof LastHttpContent) {
isList.add(NettyInputStream.END_OF_INPUT);
}
}
#Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
if(asyncConnectorCallback != null) {
nettyChannelPoolConnector.executorService.execute(() -> asyncConnectorCallback.failure(cause));
}
future.completeExceptionally(cause);
isList.add(NettyInputStream.END_OF_INPUT_ERROR);
}
The references needed to be passed to the SimpleChannelInboundHandler is what is packed into the ClientRequestDTO as seen in the first code block.
I am not sure as it is not a tested code. But it could be achieved by the following code.
SimpleChannelPool sPool = poolMap.get(Req.getAddress());
Future<Channel> f = sPool.acquire();
f.get().pipeline().addLast("inbound", new NettyClientInBoundHandler(Req, jbContext, ReportData));
f.addListener(new NettyClientFutureListener(this.Req, sPool));
where Req, jbContext, ReportData could be input data for InboundHandler().
I am new to spark streaming. I want to stream a url online in order to retrieve info from a certain URL, I used the JavaCustomReceiver in order to stream a url.
This is the code I'm using (source)
public class JavaCustomReceiver extends Receiver<String> {
private static final Pattern SPACE = Pattern.compile(" ");
public static void main(String[] args) throws Exception {
SparkConf sparkConf = new SparkConf().setAppName("JavaCustomReceiver");
JavaStreamingContext ssc = new JavaStreamingContext(sparkConf, new Duration(1000));
JavaReceiverInputDStream<String> lines = ssc.receiverStream(
new JavaCustomReceiver("http://stream.meetup.com/2/rsvps", 80));
JavaDStream<String> words = lines.flatMap(new
FlatMapFunction<String, String>() {
#Override
public Iterator<String> call(String x) {
return Arrays.asList(SPACE.split(x)).iterator();
}
});
JavaPairDStream<String, Integer> wordCounts = words.mapToPair(
new PairFunction<String, String, Integer>() {
#Override
public Tuple2<String, Integer> call(String s) {
return new Tuple2<>(s, 1);
}
}).reduceByKey(new Function2<Integer, Integer, Integer>() {
#Override
public Integer call(Integer i1, Integer i2) {
return i1 + i2;
}
});
wordCounts.print();
ssc.start();
ssc.awaitTermination();
}
String host = null;
int port = -1;
public JavaCustomReceiver(String host_, int port_) {
super(StorageLevel.MEMORY_AND_DISK_2());
host = host_;
port = port_;
}
public void onStart() {
new Thread() {
#Override
public void run() {
receive();
}
}.start();
}
public void onStop() {
}
private void receive() {
try {
Socket socket = null;
BufferedReader reader = null;
String userInput = null;
try {
// connect to the server
socket = new Socket(host, port);
reader = new BufferedReader(
new InputStreamReader(socket.getInputStream(), StandardCharsets.UTF_8));
// Until stopped or connection broken continue reading
while (!isStopped() && (userInput = reader.readLine()) != null) {
System.out.println("Received data '" + userInput + "'");
store(userInput);
}
} finally {
Closeables.close(reader, /* swallowIOException = */ true);
Closeables.close(socket, /* swallowIOException = */ true);
}
restart("Trying to connect again");
} catch (ConnectException ce) {
// restart if could not connect to server
restart("Could not connect", ce);
} catch (Throwable t) {
restart("Error receiving data", t);
}
}
}
However, I keep getting a java.net.UnknownHostException
How can I fix this? What is wrong with the code that I'm using ?
After reading the code of the custom receiver referenced, it is clear that it is a TCP receiver that connects to a host:port and not an HTTP receiver that could take an URL. You'll have to change the code to read from an HTTP endpoint.
I am using TimerTask and ImageLoader class to load n image to an image item.
public class Imageloader implements Runnable{
private ImageItem item=null;
private String url=null;
/*
* initializes the imageItem
*/
public Imageloader(ImageItem item,String url){
this.item=item;
this.url=url;
}
private Image getImage(String url) throws IOException {
item.setLabel(item.getLabel()+12);
System.out.println("Test 5");
HttpConnection connection = null;
DataInputStream inp = null;
int length;
byte[] data;
try {System.out.println("Test 6");
connection = (HttpConnection) Connector.open(url);
item.setLabel(item.getLabel()+13);
connection.getResponseMessage();
System.out.println("Test 7");
length = (int) connection.getLength();
item.setLabel(item.getLabel()+14);
System.out.println("Length is "+length);
System.out.println("Test 8");
data = new byte[length];
inp = new DataInputStream(connection.openInputStream());
item.setLabel(item.getLabel()+15);
System.out.println("Test 9");
inp.readFully(data);
item.setLabel(item.getLabel()+16);
System.out.println("Test 10");
return Image.createImage(data, 0, data.length);
}
finally {
if (connection != null) connection.close();
if (inp != null)inp.close();
}
}
public void run() {
System.out.println("Test 1");
Image image=null;
try{
if (url!=null){
System.out.println("Test 2");
image=getImage(url);
System.out.println("Test 3");
item.setImage(image);
item.setLabel(item.getLabel()+17);
System.out.println("Test 4");
}
else{
item.setAltText("Map address specified is incorrect");
}
}
catch(IOException e){
item.setAltText("Map cannot be loaded now");
}
}
}
public class MapTimer extends TimerTask{
DatagramConnection connection=null;
String message=null;
Imageloader imageretriever;
ImageItem item=null;
MapTimer (DatagramConnection connection,String message,ImageItem Img_map ){
this.connection=connection;
this.message=message;
this.item=Img_map;
item.setLabel(item.getLabel()+1);
System.out.println("Map is initizlized...");
}
public void run() {
System.out.println("Map starting...");
item.setLabel(item.getLabel()+2);
String serverquery=null;
try {
item.setLabel(item.getLabel()+3);
sendMessage(message);
item.setLabel(item.getLabel()+4);
//serverquery=receiveMessage() ;
item.setLabel(item.getLabel()+5);
//item.setLabel(" Loading...." );
//formatmessage(serverquery);
String url="http://maps.google.com/maps/api/staticmap?center=Brooklyn+Bridge,New+York,NY&zoom=14&size=512x512&maptype=roadmap"+
"&markers=color:blue|label:S|40.702147,-74.015794&markers=color:green|label:G|40.711614,-74.012318"+
"&markers=color:red|color:red|label:C|40.718217,-73.998284&sensor=false";
Imageloader Im=new Imageloader(item,url);
item.setLabel(item.getLabel()+6);
(new Thread(Im)).start();
item.setLabel(item.getLabel()+7);
System.out.println("server map query is::: "+serverquery);
} catch (IOException ex) {
System.out.println("Error2"+ex);
}
catch(Exception e){
System.out.println("Error3"+e);
}
}
/*
* Sends a message via UDP to server
*/
private void sendMessage(String message) throws IOException{
Datagram packet_send=null;
if (connection != null){
byte[] packetsenddata=message.getBytes();
packet_send = connection.newDatagram(packetsenddata,packetsenddata.length);
connection.send(packet_send);
packet_send = null;
}
}
}
This is how I set the Timer;
MapTimer maptimer=new MapTimer (connection,mapquery ,Img_map );
Timer timer=new Timer();
timer.schedule(maptimer, 5000, 100000);
It's working fine with the enulator but as I deploy it on my mob,the image is not loading..
The image label is somewhat like Stopping 234567234567 which implies that my timer is running fine. It is not entering the ImageLoader class... How do get to load this image?
This is difficult to say without further debuggind. I recommend you to use Micrologger + a web server, in order to debug your midlets on the device.
Looking to your code, I suspect of this line length = (int) connection.getLength();. Could it fail on Nokia's IO library implementation?