I wrote a ServerResource below with restlet-android-2.1.4. If the I set SIZE to 1024 * 12 + 485, it works. But if I change SIZE to 1024 * 12 + 486 this handle will pending.
public class DataResource extends ServerResource {
public static final int SIZE = 1024 * 12 + 485;
#Get
public Representation getResource(Representation entity) {
return new OutputRepresentation(MediaType.ALL) {
#Override
public void write(OutputStream outputStream) throws IOException {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < SIZE; i++) {
sb.append('E');
}
outputStream.write(sb.toString().getBytes());
outputStream.close();
}
};
}
}
Dive into the code, change the write function in WritableSocketChannel.java(in restlet source code) and it will work.
I don't know whether it's a bug.
from
public int write(ByteBuffer src) throws IOException {
return getWrappedChannel().write(src);
}
to
public int write(ByteBuffer src) throws IOException {
int count = 0;
while (src.hasRemaining()) {
count += getWrappedChannel().write(src);
}
return count;
}
According to java doc.
Some types of channels, depending upon their state, may write only
some of the bytes or possibly none at all. A socket channel in
non-blocking mode, for example, cannot write any more bytes than are
free in the socket's output buffer.
Related
I have a Magellan scanner/scale. It is connected to my pc through rs232. When i send the command "S11" on ComTestSerial programm, i receive the weight. However, with my vb.net code i cannot receive a response. As a result i get a TimeoutException.
The file that sends the command:
Dim yy() As Byte = System.Text.Encoding.ASCII.GetBytes("S11" & vbLf)
Me.Port.Send(yy)
Dim input = Me.Port.Receive
Return Me.ExtractMeasurement(input)
The file that writes and reads from serialport:
public void Send(byte b)
{
byte[] bytes = new byte[1] { b };
this.Send(bytes);
}
public void Send(byte[] bytes)
{
this.Send(bytes, 0, bytes.Length);
}
public void Send(byte[] bytes, int offset, int count)
{
this._port.Write(bytes, offset, count);
}
public byte[] Receive()
{
int attempts = 1;
Boolean dataReceived;
try
{
while (!this.DataReceived && this._port.BytesToRead == 0 && attempts < 15)
{
System.Threading.Thread.Sleep(100);
attempts++;
}
}
finally
{
dataReceived = this.DataReceived;
this.DataReceived = false;
}
if (!dataReceived && this._port.BytesToRead == 0) throw new TimeoutException();
byte[] bytes = new byte[this._port.BytesToRead];
this._port.Read(bytes, 0, bytes.Length);
return bytes;
}
I can't understand why BytesToRead and BytesToWrite stays 0 after this._port.Write(bytes, offset, count);
Here is the serialportconfig.xml file
<PortName>COM3:</PortName>
<BaudRate>Baud_9600</BaudRate>
<DataBits>Eight</DataBits>
<Parity>None</Parity>
<StopBits>One</StopBits>
<FlowCtrl>CtsRts</FlowCtrl>
Update: i figure out that if i send vbCr instead of vbLf i sometimes get the right response back. But the problem is SOMETIMES. I sometimes get a TimeoutException and sometimes get the response. I am using an adaptor from RS232 to usb. Could this be the problem?
Here is all the code related to the serial:
public class SerialPortAdapter
{
#region Private Members
private System.IO.Ports.SerialPort _port;
private Object _dataReceivedLock = new Object();
private Boolean _dataReceived;
#endregion
#region Constructor/Destructor
public SerialPortAdapter(SerialCnfg config)
{
if (string.IsNullOrEmpty(config.PortName))
{
this._port = new System.IO.Ports.SerialPort();
}
else
{
string portName = config.PortName.TrimEnd(':');
this._port = new System.IO.Ports.SerialPort(portName);
}
this._port.WriteTimeout = 2000;
this._port.ReadTimeout = 2000;
this._port.SetBaudRate(config.BaudRate);
this._port.SetDataBits(config.DataBits);
this._port.SetStopBits(config.StopBits);
this._port.SetHandshake(config.FlowCtrl);
this._port.SetParity(config.Parity);
}
~SerialPortAdapter()
{
this.Close();
this._port = null;
}
#endregion
#region Public Properties
public Boolean IsOpen
{
get { return this._port.IsOpen; }
}
public System.Text.Encoding Encoding
{
get { return this._port.Encoding; }
set { this._port.Encoding = value; }
}
#endregion
#region Public Methods
public void Open()
{
if (this.IsOpen) return;
this.DataReceived = false;
this.AttachPortHandlers();
this._port.Open();
}
public void Close()
{
if (!this.IsOpen) return;
this._port.Close();
this.DetachPortHandlers();
this.DataReceived = false;
}
public void Send(byte b)
{
byte[] bytes = new byte[1] { b };
this.Send(bytes);
}
public void Send(byte[] bytes)
{
this.Send(bytes, 0, bytes.Length);
}
public void Send(byte[] bytes, int offset, int count)
{
this._port.Write(bytes, offset, count);
}
public byte[] Receive()
{
int attempts = 1;
Boolean dataReceived;
try
{
while (!this.DataReceived && this._port.BytesToRead == 0 && attempts < 15)
{
System.Threading.Thread.Sleep(100);
attempts++;
}
}
finally
{
dataReceived = this.DataReceived;
this.DataReceived = false;
}
if (!dataReceived && this._port.BytesToRead == 0) throw new TimeoutException();
byte[] bytes = new byte[this._port.BytesToRead];
this._port.Read(bytes, 0, bytes.Length);
return bytes;
}
#endregion
#region Private Properties
private Boolean DataReceived
{
get
{
lock (this._dataReceivedLock)
{
return this._dataReceived;
}
}
set
{
lock (this._dataReceivedLock)
{
this._dataReceived = value;
}
}
}
#endregion
#region Initialization/Finalization
private void AttachPortHandlers()
{
this._port.DataReceived += new System.IO.Ports.SerialDataReceivedEventHandler(this.OnDataReceived);
}
private void DetachPortHandlers()
{
this._port.DataReceived -= new System.IO.Ports.SerialDataReceivedEventHandler(this.OnDataReceived);
}
#endregion
#region Event Handlers
private void OnDataReceived(Object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
{
this.DataReceived = true;
}
#endregion
}
Based on the code you posted, you are attempting to handle your own timeout exception. SerialPort class has its own built in timeout (ie, ReadTimeout, WriteTimeout) which you set in the constructor. Therefore you do not need the other methods to handle the timeout as it would be redundant. Moreover, stay away from the System.Threading.Sleep method as it can be a huge waste of resources Why is Thread.Sleep so harmful.
I suggest that you refactor your code a bit to get rid of the self imposed Throw TimeoutException.
Here is just a suggestion:
public byte[] Receive()
{
try
{
byte[] bytes = new byte[]{};
while(_port.BytesToRead > 0)
{
bytes = new byte[this._port.BytesToRead];
this._port.Read(bytes, 0, bytes.Length);
}
}
catch (TimeoutException ex)
{
Console.WriteLine(ex.Message);
}
finally
{
this.DataReceived = false;
}
return bytes;
}
It appears that Magellan can work if you resend the command to request the weight(S11). So the solution for me was whenever i have _port.bytesToRead=0 after this._port.Write(bytes, offset, count) , then i resend the command S11. Eventually, it will response the right result.
I am new to netty and I have a problem using my netty program.
in initConnection method I want to make a different channelpool for each group.
when user group A come in my sendToMessage I want to create channelPool A
like this way user group B come in my sendToMessage I want to create channelPool B and next time if user group A come in again, i will return channelPool A
Is it right to try doing this? Is it possible?
FixedChannelPool error handling
tell me how can I FixedChannelPool error handling? Could I use acquireTimeoutMillis over time.how?
Here is my code
#Service
public class NettyPoolService {
public static final AttributeKey<CompletableFuture<String>> FUTURE = AttributeKey.valueOf("future");
private static final StringDecoder stringDecoder = new StringDecoder(CharsetUtil.UTF_8);
private static final StringEncoder stringEncoder = new StringEncoder(CharsetUtil.UTF_8);
private static ChannelPool channelPool;
private static EventLoopGroup eventLoopGroup;
#Value("${host}")
private String host;
#Value("${port}")
private String port;
#Value("${connection.count}")
private String numberOfConnections;
#Value("${thread.count}")
private String numberOfThreads;
private synchronized void initConnection (String host, int port, int numberOfThreads, int numberOfConnections,String userGroup) {
if ( (channelPool != null) && (eventLoopGroup != null) ) {
return;
}
System.out.println("#############################################");
System.out.println("initConnection start");
eventLoopGroup = new NioEventLoopGroup(numberOfThreads);
Bootstrap bootstrap = new Bootstrap();
bootstrap.option(ChannelOption.ALLOCATOR, PooledByteBufAllocator.DEFAULT);
bootstrap.option(ChannelOption.SO_KEEPALIVE, true);
//bootstrap.option(ChannelOption.WRITE_BUFFER_HIGH_WATER_MARK, 32 * 1024);
//bootstrap.option(ChannelOption.WRITE_BUFFER_LOW_WATER_MARK, 8 * 1024);
//bootstrap.option(ChannelOption.TCP_NODELAY, true);
bootstrap.group(eventLoopGroup).channel(NioSocketChannel.class).remoteAddress(host, port);
int acquireTimeoutMillis = 10000;
int maxPendingAcquires = Integer.MAX_VALUE;
channelPool = new FixedChannelPool(bootstrap,
new AbstractChannelPoolHandler() {
public void channelCreated(Channel ch) throws Exception {
ChannelPipeline pipeline = ch.pipeline();
// decoders
pipeline.addLast("framer", new DelimiterBasedFrameDecoder(8192, Delimiters.lineDelimiter()));
pipeline.addLast("stringDecoder", stringDecoder);
// encoders
pipeline.addLast("stringEncoder", stringEncoder);
// business logic handler
pipeline.addLast("clientHandler", new ClientPoolHandler(channelPool));
}
},
ChannelHealthChecker.ACTIVE,//eventloop
AcquireTimeoutAction.NEW, //timeout
acquireTimeoutMillis, //
numberOfConnections, //
maxPendingAcquires); //
System.out.println("initConnection End");
System.out.println("#############################################");
}//initConnection
public void sendToMessage(String message,String GroupId) {
System.out.println("=============GroupId=============:"+GroupId);
if (channelPool == null) {
initConnection(host, Integer.parseInt(port.trim()), Integer.parseInt(numberOfThreads.trim()), Integer.parseInt(numberOfConnections.trim()) );
}
final CompletableFuture<String> future = new CompletableFuture<String>();
Future<Channel> channelFuture = channelPool.acquire();
System.out.println("=============channelFuture.get()=============:"+channelFuture.toString());
channelFuture.addListener(new FutureListener<Channel>() {
public void operationComplete(Future<Channel> f) {
if (f.isSuccess()) {
Channel channel = f.getNow();
channel.attr(NettyPoolClientService.FUTURE).set(future);
channel.writeAndFlush(message, channel.voidPromise());
}
}
});
channelFuture.syncUninterruptibly();
}//sendToBnp
}
I am exploring Ignite dataStreamer with the following code.
But the output is:
For MessageKey0001, the output all displays data is null.
For MessageKey0003, the output also all displays data is null
For MessageKey0002, the output shows nothing, looks that receiver code is not run
When I change
dataStreamer.addData(i, "data-" + i);
to
IgniteFuture future = dataStreamer.addData(i, "data-" + i);
future.get();
The future.get() doesn't return, looks addData doesn't finish anyway?
I am not sure where the problem is, can someone take a look? Thanks!
package ignite.streamer;
import org.apache.ignite.*;
import org.apache.ignite.cache.query.annotations.QuerySqlField;
import org.apache.ignite.configuration.CacheConfiguration;
import org.apache.ignite.stream.StreamReceiver;
import javax.cache.Cache;
import java.io.Serializable;
import java.util.Collection;
import java.util.Map;
class IgniteDataStreamer_Person implements Serializable {
#QuerySqlField(index = true)
private String name;
#QuerySqlField(index = true)
private int age;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
}
public class IgniteDataStreamerTest {
public static void main(String[] args) {
String configPath = "D:/Software/apache-ignite-fabric-1.7.0-bin/apache-ignite-fabric-1.7.0-bin/config/default-config.xml";
Ignite ignite = Ignition.start(configPath);
CacheConfiguration<Integer, String> cfg = new CacheConfiguration<Integer, String>();
String cacheName = "stream_cache";
cfg.setName(cacheName);
cfg.setIndexedTypes(Integer.class, IgniteDataStreamer_Person.class);
Cache cache = ignite.getOrCreateCache(cfg);
IgniteDataStreamer<Integer, String> dataStreamer = ignite.dataStreamer(cacheName);
for (int i = 0; i < 3; i++) {
dataStreamer.addData(i, "data-" + i);
}
//null is got from cache
for (int i = 0; i < 3; i++) {
System.out.println(String.format("0001: data is %s ", cache.get(i)));
}
dataStreamer.receiver(new StreamReceiver<Integer, String>() {
public void receive(IgniteCache<Integer, String> cache, Collection<Map.Entry<Integer, String>> entries) throws IgniteException {
//nothing is printed to console
for (Map.Entry<Integer, String> entry : entries) {
System.out.println(String.format("0002: key is: %s, value is: %s", entry.getKey(), entry.getValue()));
}
}
});
//null is got from cache
for (int i = 0; i < 3; i++) {
System.out.println(String.format("0003: data is %s ", cache.get(i)));
}
ignite.close();
}
}
DataStreamer uses batches in order to provide good performance. You should flush data in your case (use flush() method) before block on future.get() method.
Please, see IgniteDataStreamer javadocs for details.
I am trying to resize an image from by db. Below is the webservlet where I get the blob from my database and try to resize it using UtilImage.
Problem: The image i tried to resize isn't shown in my browser and my console hasn't listed any stacktraces. After the UtilImage.resize() call, which returns a new BufferedImage, the imageType has changed from 5 to 1.
#WebServlet("/images")
public class BildService extends HttpServlet {
private static final long serialVersionUID = 1L;
#EJB
private LesenService lesenService;
private Veranstaltung veranstaltung;
#Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
Integer veranstaltungId = Integer.parseInt(request.getParameter("id"));
veranstaltung = lesenService.getVeranstaltungByVeranstaltungId(veranstaltungId);
if (veranstaltung == null) {
response.sendError(HttpServletResponse.SC_NOT_FOUND);
return;
}
response.setContentType(veranstaltung.getFormat());
OutputStream os = response.getOutputStream();
byte[] img = UtilImage.resizeScalr(veranstaltung.getBild(), veranstaltung.getFormat());
os.write(img);
}
}
This is my UtilImage class:
public class UtilImage {
public static final byte[] resizeScalr(byte[] img, String type) {
if (img != null) {
BufferedImage bImage = getBufferedImage(img);
double scaleFactor = getScaleFactor(bImage.getWidth(), UtilKonstanten.PICTURE_WIDTH);
int targetWidth = (int) (scaleFactor * bImage.getWidth());
int targetHeight = (int) (scaleFactor * bImage.getHeight());
// return getByteArray(Scalr.resize(bImage, targetWidth,
// targetHeight), type);
return getByteArray(Scalr.resize(bImage, Scalr.Method.BALANCED, targetWidth, targetHeight), type);
}
return null;
}
private static final double getScaleFactor(int width, int wishwidth) {
return (double) wishwidth / width;
}
private static final BufferedImage getBufferedImage(byte[] array) {
InputStream is = new ByteArrayInputStream(array);
BufferedImage img;
try {
img = ImageIO.read(is);
return img;
} catch (IOException e) {
// TODO
e.printStackTrace();
}
return null;
}
private static final byte[] getByteArray(BufferedImage img, String type) {
try {
ByteArrayOutputStream os = new ByteArrayOutputStream();
ImageIO.write(img, type, os);
byte[] byteArray = os.toByteArray();
os.close();
return byteArray;
} catch (IOException e) {
// TODO
e.printStackTrace();
}
return null;
}
}
Thanks a lot for your help!
Unfortunately I didn't post the answer to this question.
As far as I know it was something with the type, that wasn't saved correctly and in cause of that the browser wasn't able to resolve the type.
--> "img" instead of "application/img" or something like that.
I have a service that returns the current position every 30 seconds, my problem is that the service consumes about 40% of the battery. The GPS icon is always active, even if I increase the time interval. I see this problem with my Nexus 4 android 4.4.2. Once the callback OnLocationChanged is called, the GPS is awake all the time and this consumes the entire battery. With my other Phone Nexus One android 2.2.3 , I do not see this problem, the GPS turns on every 30 seconds and turns off. And I have no battery consommation. The service use Location Request, with .setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY), excepted to use GPS and Network and is not the case. I thinks there is a problem with android 4.4.2 or is Google play service
Here my service code:
public class MyServiceGpsDebug extends Service implements
GooglePlayServicesClient.ConnectionCallbacks,
GooglePlayServicesClient.OnConnectionFailedListener,LocationListener
{
IBinder mBinder = new LocalBinder();
private LocationClient mLocationClient;
private LocationRequest mLocationRequest;
// Flag that indicates if a request is underway.
private boolean mInProgress;
private Boolean servicesAvailable = false;
public class LocalBinder extends Binder
{
public MyServiceGpsDebug getServerInstance()
{
return MyServiceGpsDebug.this;
}
}
#Override
public void onCreate()
{
super.onCreate();
mInProgress = false;
// Create the LocationRequest object
mLocationRequest = LocationRequest.create();
// Use high accuracy
mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
// Set the update interval to 5 seconds
mLocationRequest.setInterval(Constants.UPDATE_INTERVAL);
// Set the fastest update interval to 1 second
mLocationRequest.setFastestInterval(Constants.FASTEST_INTERVAL);
servicesAvailable = servicesConnected();
mLocationClient = new LocationClient(this, this, this);
}
private boolean servicesConnected()
{
// Check that Google Play services is available
int resultCode = GooglePlayServicesUtil.isGooglePlayServicesAvailable(this);
// If Google Play services is available
if (ConnectionResult.SUCCESS == resultCode)
{
return true;
}
else
{
return false;
}
}
public int onStartCommand (Intent intent, int flags, int startId)
{
super.onStartCommand(intent, flags, startId);
if(!servicesAvailable || mLocationClient.isConnected() || mInProgress)
return START_STICKY;
setUpLocationClientIfNeeded();
if(!mLocationClient.isConnected() || !mLocationClient.isConnecting() && !mInProgress)
{
appendLog(DateFormat.getDateTimeInstance().format(new Date()) + ": Started", Constants.LOG_FILE);
mInProgress = true;
mLocationClient.connect();
}
return START_STICKY;
}
private void setUpLocationClientIfNeeded()
{
if(mLocationClient == null)
mLocationClient = new LocationClient(this, this, this);
}
#Override
public void onLocationChanged(Location location)
{
// Report to the UI that the location was updated
String msg = Double.toString(location.getLatitude()) + "," + Double.toString(location.getLongitude());
Log.d("debug", msg);
// Toast.makeText(this, msg, Toast.LENGTH_SHORT).show();
appendLog(msg, Constants.LOCATION_FILE);
}
#Override
public IBinder onBind(Intent intent)
{
return mBinder;
}
public String getTime()
{
SimpleDateFormat mDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
return mDateFormat.format(new Date());
}
public void appendLog(String text, String filename)
{
File logFile = new File(filename);
if (!logFile.exists())
{
try
{
logFile.createNewFile();
}
catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}
try
{
//BufferedWriter for performance, true to set append to file flag
BufferedWriter buf = new BufferedWriter(new FileWriter(logFile, true));
buf.append(text);
buf.newLine();
buf.close();
}
catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}
#Override
public void onDestroy()
{
// Turn off the request flag
mInProgress = false;
if(servicesAvailable && mLocationClient != null)
{
mLocationClient.removeLocationUpdates(this);
// Destroy the current location client
mLocationClient = null;
}
// Display the connection status
// Toast.makeText(this, DateFormat.getDateTimeInstance().format(new Date()) + ": Disconnected. Please re-connect.", Toast.LENGTH_SHORT).show();
appendLog(DateFormat.getDateTimeInstance().format(new Date()) + ": Stopped", Constants.LOG_FILE);
super.onDestroy();
}
#Override
public void onConnected(Bundle bundle)
{
// Request location updates using static settings
mLocationClient.requestLocationUpdates(mLocationRequest, this);
appendLog(DateFormat.getDateTimeInstance().format(new Date()) + ": Connected", Constants.LOG_FILE);
}
#Override
public void onDisconnected()
{
// Turn off the request flag
mInProgress = false;
// Destroy the current location client
mLocationClient = null;
// Display the connection status
// Toast.makeText(this, DateFormat.getDateTimeInstance().format(new Date()) + ": Disconnected. Please re-connect.", Toast.LENGTH_SHORT).show();
appendLog(DateFormat.getDateTimeInstance().format(new Date()) + ": Disconnected", Constants.LOG_FILE);
}
#Override
public void onConnectionFailed(ConnectionResult connectionResult)
{
mInProgress = false;
if (connectionResult.hasResolution())
{
// If no resolution is available, display an error dialog
} else {
}
}
public final class Constants
{
// Milliseconds per second
private static final int MILLISECONDS_PER_SECOND = 1000;
// Update frequency in seconds
private static final int UPDATE_INTERVAL_IN_SECONDS = 60;
// Update frequency in milliseconds
public static final long UPDATE_INTERVAL = MILLISECONDS_PER_SECOND * UPDATE_INTERVAL_IN_SECONDS;
// The fastest update frequency, in seconds
private static final int FASTEST_INTERVAL_IN_SECONDS = 60;
// A fast frequency ceiling in milliseconds
public static final long FASTEST_INTERVAL = MILLISECONDS_PER_SECOND * FASTEST_INTERVAL_IN_SECONDS;
// Stores the lat / long pairs in a text file
public static final String LOCATION_FILE = "sdcard/location.txt";
// Stores the connect / disconnect data in a text file
public static final String LOG_FILE = "sdcard/log.txt";
/**
* Suppress default constructor for noninstantiability
*/
private Constants() {
throw new AssertionError();
}
}
}
I have similar problem with Nexus 4. My app has a service which uses location updates (fusion location or android providers, not both). Everything works OK for all android phones but in Nexus4 after some time the phone gets hot and slow even if i kill the app (through DDMS, 100% stopped). The only solution is to kill Google play services .
I think that there is a bug in play services for nexus 4. There is a dirty solution to kill Google Play Services every 30mins for example if phone=nexus4, but i do not know if it is possible