I know this has been asked in a few different ways, but I've been working on this for 2 days with no avail. My code is failing in that the receiving side throws EOF exceptions constantly. Can someone point me in the right direction?
Receiving side:
class ReceiveThread extends Thread {
ReceiveThread() {
}
#Override
public void run() {
System.out.println("Receive Thread Start");
DataInputStream in;
try {
} catch (Exception e) {
return;
}
try {
in = new DataInputStream(connection.getInputStream());
while (true) {
if (!connection.isConnected()) {
System.out.println("Connection not connected");
break;
}
try {
int len = in.readInt();
byte[] data = new byte[len];
System.out.println("Image size: " + len);
if (len > 0) {
in.readFully(data, 0, len);
BufferedImage bi = ImageIO.read(new ByteArrayInputStream(data));
panel.updateImage(bi);
panel.repaint();
}
in.close();
} catch (Exception e) {
}
pause(100);
}
} catch (Exception e) {
}
}
public void pause(long time) {
try {
Thread.sleep(time);
} catch (Exception e) {
}
}
}
Sending side:
class UpdateScreenThread extends Thread {
Robot robot;
public UpdateScreenThread() {
try {
robot = new Robot();
System.out.println("Update Thread Created");
} catch (Exception e) {
}
}
#Override
public void run() {
System.out.println("Update Thread Running");
Settings.isSharing = true;
Dimension screenSize;
screenSize = Toolkit.getDefaultToolkit().getScreenSize();
Rectangle screenRectangle = new Rectangle(screenSize);
ByteArrayOutputStream baos = new ByteArrayOutputStream();
DataOutputStream out;
try {
out = new DataOutputStream(s.getOutputStream());
} catch (Exception e) {
return;
}
while (s.isConnected()) {
//System.out.println("test");
BufferedImage bi = robot.createScreenCapture(screenRectangle);
try {
ImageIO.write(bi, "PNG", baos);
baos.flush();
byte[] bytes = baos.toByteArray();
out.flush();
out.writeInt(bytes.length);
out.flush();
out.write(bytes);
System.out.println("Image sent");
} catch (Exception e) {
}
pause(500);
}
try {
out.close();
} catch (Exception e) {
}
Settings.isSharing = false;
}
}
Thanks to anyone who can help. This is driving me INSANE.
Reduced to the essentials, this is your read loop:
public void run() {
//...
try {
in = new DataInputStream(connection.getInputStream());
while (true) {
//...
try {
int len = in.readInt();
byte[] data = new byte[len];
in.readFully(data, 0, len);
//...
in.close();
} catch (Exception e) {
}
pause(100);
}
} catch (Exception e) {
}
}
Note that the while (true) {...} includes in.close(). Move the close out of the loop.
Related
I am trying to read and write shape objects to a file for a drawing program, but when I try to read from the file it shows that the file is empty. The file is definitely being written to and updated, but when trying to read from the file it is showing that there are zero bytes available. The shape class is serializable so I am not sure why this isn't working at all.
public void writeToFile() {
try {
FileOutputStream fileOut = new FileOutputStream("C:\\Users\\johnm\\eclipse-workspace\\CSE205_Assignment05\\save.ser");
ObjectOutputStream out = new ObjectOutputStream(fileOut);
for (Shape item : shapes) {
out.writeObject(item);
}
out.close();
fileOut.close();
System.out.println("Serialized data is saved in output.ser");
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
public void loadFromFile() {
boolean cont = true;
Shape shape = null;
int count = 0;
while (cont) {
try {
FileInputStream fileIn = new FileInputStream("C:\\Users\\johnm\\eclipse-workspace\\CSE205_Assignment05\\save.ser");
ObjectInputStream in = new ObjectInputStream(fileIn);
System.out.println(in.available() + " Bytes");
if (in.available() != 0) {
shape = (Shape) in.readObject();
if (shape != null) {
shapes.add(shape);
count++;
} else {
System.out.println("Shape is null");
}
} else {
cont = false;
}
in.close();
fileIn.close();
System.out.println("Deserialized " + count + " Objects");
} catch (ClassNotFoundException c) {
System.out.println("Class not found");
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
Alright for some reason the .available() method isn't showing any bytes regardless of if there actually are any or not. To counter this I just threw in another try/catch statement where it continuously reads objects until it hits an EOFException and catches itself.
My code ended up looking like this once working.
public void loadFromFile() {
//** Loads set of shape objects from file
Shape shape = null;
int count = 0;
try {
FileInputStream fileIn = new FileInputStream("save.ser");
ObjectInputStream in = new ObjectInputStream(fileIn);
System.out.println(in.available() + " Bytes");
try {
while (true) {
shape = (Shape) in.readObject();
if (shape != null) {
shapes.add(shape);
count++;
} else {
System.out.println("Shape is null");
}
}
} catch (EOFException e) {
System.out.println("End of file exception");
}
in.close();
fileIn.close();
System.out.println("Deserialized " + count + " Objects");
repaint();
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
I am trying to read GPS data from a serial port(ttyACM0) in java using jssc jar which I need to display as a label in a JavaFx application. I have a created a thread for reading the GPS data but this thread is consuming 100% CPU(checked using top command + Shift H) because of which my GUI is getting freezed. This is a sample code I have written for reading GPS data
Serial Interface
import jssc.*;
public class SerInterface {
String portName;
int baud;
boolean lineMode;
// The chosen Port itself
SerialPort port;
public byte[] recvBuff;
public SerInterface(String portName, int baud, boolean lineMode) {
this.portName = portName;
this.baud = baud;
this.lineMode = lineMode;
recvBuff = new byte[8192];
openPort();
if((port == null) || (!port.isOpened()))
System.out.println(portName + " not opened successfully");
}
void openPort() {
port = new SerialPort(portName);
if(port == null)
return;
try {
port.openPort();
} catch (SerialPortException e) {
e.printStackTrace();
}
try {
if(port.isOpened())
port.setParams(SerialPort.BAUDRATE_9600, SerialPort.DATABITS_8, SerialPort.STOPBITS_1, SerialPort.PARITY_NONE);
else
return;
} catch (SerialPortException e) {
e.printStackTrace();
}
System.out.println(portName + " opened successfully");
}
public int recvData() {
int len = 0;
if(port.isOpened()) {
try {
byte[] buff = port.readBytes();
if((buff == null) || (buff.length == 0))
return 0;
len = buff.length;
if(len > recvBuff.length)
len = recvBuff.length;
System.arraycopy(buff, 0, recvBuff, 0, len);
buff = null;
} catch (SerialPortException e) {
e.printStackTrace();
}
}
return len;
}
public void sendData(byte[] sendBuff, int len) {
if(port.isOpened()) {
try {
port.writeBytes(sendBuff);
} catch (SerialPortException e) {
e.printStackTrace();
}
}
}
public boolean validatePort() {
if(!port.isOpened()) {
openPort();
if(port.isOpened())
return true;
else
return false;
}
else
return true;
}
public void flushPort() {
if(port.isOpened()) {
try {
port.purgePort(SerialPort.PURGE_RXCLEAR | SerialPort.PURGE_TXCLEAR);
} catch (SerialPortException e) {
e.printStackTrace();
}
}
}
public void closePort() {
if(port.isOpened()) {
try {
port.closePort();
System.out.println("port closed");
} catch (SerialPortException e) {
e.printStackTrace();
}
}
}
}
GPSReceiver thread extends SerInterface and implements Runnable
#Override
public void run() {
flushPort();
while(true) {
if(!validatePort()) {
try {
sleep(5000);
} catch (InterruptedException e) {
e.printStackTrace();
}
continue;
}
int dataLength = recvData();
if(dataLength < 2)
continue;
try {
InputStream gpsStream = new ByteArrayInputStream(recvBuff, 0, dataLength);
BufferedReader br = new BufferedReader(new InputStreamReader(gpsStream, StandardCharsets.US_ASCII));
while(true) {
try {
if (!((output = br.readLine()) != null)) break;
} catch (IOException e) {
e.printStackTrace();
}
extractData();
}
}
catch(NullPointerException e) {
e.printStackTrace();
}
}
Main Thread
GPSInterface objGPSThreadInterface = new GPSInterface(GPSPortName, 9600, true);
GPSThreadInt = new Thread(objGPSThreadInterface, "GPSINT");
I am using jdk-13.0.1 and jssc-2.9.1 jar
I am trying to build a client server model in java using sockets to share files.
It works fine for one iteration of loop for sending a file but after that no data is received on the server. Please take a look at my code and suggest me something to correct this.
FileClient.java
public class FileClient {
private void listFiles() {
try {
DataInputStream dis = new DataInputStream(s.getInputStream());
while (dis.available() > 0) {
System.out.println(dis.readUTF());
}
} catch (IOException ex) {
ex.printStackTrace();
}
}
private static void selectAndDownloadFiles() {
}
private Socket s;
public FileClient(String host, int port) {
try {
s = new Socket(host, port);
} catch (Exception e) {
e.printStackTrace();
}
}
public void sendFile(String file) throws IOException {
DataOutputStream dos = new DataOutputStream(s.getOutputStream());
FileInputStream fis = new FileInputStream(file);
File myFile = new File (file);
dos.writeUTF(file);
dos.writeInt((int)myFile.length());
try {
sleep(2);
} catch (InterruptedException ex) {
Logger.getLogger(FileClient.class.getName()).log(Level.SEVERE, null, ex);
}
byte[] buffer = new byte[8192];
while (fis.read(buffer) > 0) {
dos.write(buffer);
}
}
public static void main(String[] args) {
int choice = 0;
Scanner in = new Scanner(System.in);
FileClient fc = new FileClient("localhost", 1988);
DataOutputStream dos = null;
try {
dos = new DataOutputStream(fc.s.getOutputStream());
} catch (IOException ex) {
Logger.getLogger(FileClient.class.getName()).log(Level.SEVERE, null, ex);
}
do {
try {
System.out.println("Choose an action to perform..!");
System.out.println("1. List the files..");
System.out.println("2. Select and download files");
System.out.println("3. Send a file..");
System.out.println("0. Exit..");
choice = in.nextInt();
String fileName;
switch (choice) {
case 1:
try {
dos.write(choice);
System.out.println("List Files Request Sent..!");
} catch (IOException ex) {
Logger.getLogger(FileClient.class.getName()).log(Level.SEVERE, null, ex);
}
sleep(2);
fc.listFiles();
break;
case 2:
selectAndDownloadFiles();
break;
case 3:
try {
dos.write(choice);
} catch (IOException ex) {
Logger.getLogger(FileClient.class.getName()).log(Level.SEVERE, null, ex);
}
System.out.println("Enter file name to send");
fileName = in.next();
try {
fc.sendFile(fileName);
} catch (IOException ex) {
ex.printStackTrace();
}
break;
case 0:
System.exit(0);
break;
default:
System.out.println();
}
} catch (InterruptedException ex) {
Logger.getLogger(FileClient.class.getName()).log(Level.SEVERE, null, ex);
}
} while (choice != 0);
}
}
FileServer.java
public class FileServer extends Thread {
private static ServerSocket ss;
public FileServer(int port) {
try {
ss = new ServerSocket(port);
} catch (IOException e) {
e.printStackTrace();
}
}
public void run() {
File theDir = new File("C:\\Users\\Mehroz Irshad\\Desktop\\ServerFiles");
// if the directory does not exist, create it
if (!theDir.exists()) {
boolean result = false;
try {
theDir.mkdir();
result = true;
} catch (SecurityException se) {
//handle it
}
if (result) {
System.out.println("DIR created");
}
}
while (true) {
try {
Socket clientSock = ss.accept();
DataInputStream dis = new DataInputStream(clientSock.getInputStream());
DataOutputStream dos = new DataOutputStream(clientSock.getOutputStream());
int choice;
while ((choice = dis.read()) > 0) {
switch (choice) {
case 1:
System.out.println("List Files Request Received..!");
listFiles(clientSock);
System.out.println("List Files Response Sent..!");
break;
case 2:
sendSelectedFiles();
break;
case 3:
saveFile(clientSock);
break;
}
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
private void saveFile(Socket clientSock) throws IOException {
DataInputStream dis = new DataInputStream(clientSock.getInputStream());
String fileName = dis.readUTF();
int filesize = dis.readInt();
FileOutputStream fos = new FileOutputStream("C:\\Users\\Mehroz Irshad\\Desktop\\ServerFiles\\" + fileName);
try {
sleep(2);
} catch (InterruptedException ex) {
Logger.getLogger(FileServer.class.getName()).log(Level.SEVERE, null, ex);
}
byte[] buffer = new byte[8192];
// Send file size in separate msg
int read = 0;
int totalRead = 0;
int remaining = filesize;
while ((read = dis.read(buffer, 0, Math.min(buffer.length, remaining))) > 0) {
totalRead += read;
remaining -= read;
System.out.println("read " + totalRead + " bytes.");
fos.write(buffer, 0, read);
}
//fos.close();
//dis.close();
}
public static void main(String[] args) {
FileServer fs = new FileServer(1988);
fs.start();
}
private void listFiles(Socket clientSock) {
File folder = new File("C:\\Users\\Mehroz Irshad\\Desktop\\ServerFiles");
File[] listOfFiles = folder.listFiles();
try {
DataOutputStream dos = new DataOutputStream(clientSock.getOutputStream());
if (listOfFiles.length > 0) {
for (int i = 0; i < listOfFiles.length; i++) {
dos.writeUTF(listOfFiles[i].getName());
}
} else {
dos.writeUTF("There are no files on the server..!");
}
} catch (IOException ex) {
ex.printStackTrace();
}
}
private void sendSelectedFiles() {
}
}
Attached are the images of output.
I am making a voice chat program. I have two servers one for voice and one for messages. When I connect two people I get this error, Thank you in advance. I attached the client code, ClientAudio code and the Client receive code
java.io.StreamCorruptedException: invalid type code: 00
at java.io.ObjectInputStream$BlockDataInputStream.readBlockHeader(ObjectInputStream.java:2508)
at java.io.ObjectInputStream$BlockDataInputStream.refill(ObjectInputStream.java:2543)
at java.io.ObjectInputStream$BlockDataInputStream.read(ObjectInputStream.java:2702)
at java.io.ObjectInputStream.read(ObjectInputStream.java:865)
at client.chat$ClientAudioRec.run(chat.java:388)
at java.lang.Thread.run(Thread.java:745)
its calling the error on
try {
bytesRead = ((ObjectInput) i2).read(inSound, 0, inSound.length);
} catch (Exception e) {
e.printStackTrace();
}
Code
public class Client implements Runnable { // CLIENT
private String msg;
public void run() {
try {
s1 = new Socket(ipAddress, port);
s2 = new Socket(ipAddress, 1210);
o1 = new ObjectOutputStream(s1.getOutputStream());
o1.writeObject(name);
serverListModel.addElement(name);
i1 = new ObjectInputStream(s1.getInputStream());
Thread voice = new Thread(new ClientAudio());
voice.start();
while(true) {
msg = (String) i1.readObject();
String[] namePart = msg.split("-");
if(namePart[0].equals("AddName") && !namePart[1].equals(name) && !serverListModel.contains(namePart[1])) {
serverListModel.addElement(namePart[1]);
}
if(namePart[0].equals("RemoveName") && !namePart[1].equals(name)) {
serverListModel.removeElement(namePart[1]);
}
if(!msg.equals(null) && !namePart[0].equals("AddName") && !namePart[0].equals("RemoveName")) {
chatWindow.append(msg+"\n");
}
}
} catch (IOException | ClassNotFoundException e) {
chatWindow.append("Server Closed");
e.printStackTrace();
try {
s1.close();
} catch (IOException e1) {
e1.printStackTrace();
}
mainWindow(true);
}
}
}
public class ClientAudio implements Runnable { // CLIENT AUDIO
public void run() {
try {
o2 = new ObjectOutputStream(s2.getOutputStream());
System.out.println("AUDIO");
int bytesRead = 0;
byte[] soundData = new byte[1];
Thread car = new Thread(new ClientAudioRec());
car.start();
while(true) {
bytesRead = mic.read(soundData, 0, bytesRead);
if(bytesRead >= 0) {
o2.write(soundData, 0, bytesRead);
}
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
public class ClientAudioRec implements Runnable { // CLIENT AUDIO REC
public void run() {
i2 = new ObjectInputStream(s2.getInputStream());
System.out.println("REC");
SourceDataLine inSpeaker = null;
DataLine.Info info = new DataLine.Info(SourceDataLine.class, af);
try {
inSpeaker = (SourceDataLine)AudioSystem.getLine(info);
inSpeaker.open(af);
} catch (LineUnavailableException e1) {
System.out.println("ERROR 22");
e1.printStackTrace();
}
int bytesRead = 0;
byte[] inSound = new byte[100];
inSpeaker.start();
while(bytesRead != -1)
{
try{
bytesRead = ((ObjectInput) i2).read(inSound, 0, inSound.length);
} catch (Exception e){
e.printStackTrace();
}
if(bytesRead >= 0)
{
inSpeaker.write(inSound, 0, bytesRead);
}
}
}
}
I want to make a little programm that makes a live-stream for Desktop.
It should be so that you send pictures to an echo-server and he response it to the clients.
There you get be draw the Images. Side by Side. And so it is like a movie(or something like that).
But I always get an indexoutofboundsexception. Where is the error or how can I improve my program.
The ImageIO.write lines thows the Error
//Client Main
public class Main {
public static void main(String[] args) {
Frame frm = new Frame();
Frame.Client client;
frm.setLayout(null);
frm.setDefaultCloseOperation(Frame.EXIT_ON_CLOSE);
frm.setResizable(false);
frm.setSize(1600,900);
frm.setVisible(true);
}
}
// get and send the Desktopimage
public class desktopCapture {
Robot robo;
BufferedImage screenImage;
Rectangle bounding;
public desktopCapture() {
try {
bounding = new Rectangle(0,0,1600,900);
robo = new Robot();
} catch (AWTException e) {e.printStackTrace();}
}
public void sendScreenCapture(Socket client) {
screenImage = robo.createScreenCapture(bounding);
try {
ImageIO.write(screenImage, "png", client.getOutputStream());
} catch (IOException e) {e.printStackTrace();}
}
}
// in Frame two function for actionListener Objects, so I can say who streams his Desktop and which get only the Images to.
public void readImage() {
while(true) {
try {
while((screenImage = ImageIO.read(in)) != null){
repaintScreen();
}
} catch (IOException e) {e.printStackTrace();}
}
}
public void sendImage() {
try {
while(true){
dC.sendScreenCapture(client);
System.out.println("read1");
while((screenImage = ImageIO.read(in)) != null){
System.out.println("read2");
ImageIO.write(screenImage, "png", new File("image1.png"));
Thread.sleep(250);
}
repaintScreen();
screenImage = null;
}
} catch (IOException | InterruptedException e) {e.printStackTrace();}
}
}
}
//Thread for a Client
public class handler implements Runnable {
Socket client;
OutputStream out;
InputStream in;
PrintWriter writer;
BufferedImage image;
public handler(Socket client) {
this.client = client;
}
#Override
public void run() {
try {
in = client.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(in));
while(true) {
System.out.println("write1");
while((image = ImageIO.read(in)) != null){
System.out.println("write2");
for(int i = 1;i <= Server.connectionArray.size();i++){
Socket TEMP_SOCK = (Socket)Server.connectionArray.get(i-1);
out = TEMP_SOCK.getOutputStream();
writer = new PrintWriter(out);
ImageIO.write(image, "png", TEMP_SOCK.getOutputStream());
System.out.println("write3");
}
image = null;
}
}
} catch (IOException e) {e.printStackTrace();}
}
}
I would change your for loop to:
int count = Server.connectionArray.size()
int index = count - 1;
for(int i = 0;i < count; i++){
Socket TEMP_SOCK = (Socket)Server.connectionArray.get(index);
out = TEMP_SOCK.getOutputStream();
writer = new PrintWriter(out);
ImageIO.write(image, "png", TEMP_SOCK.getOutputStream());
System.out.println("write3");
}