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Why can't my web client accept an image from my web server?

I this is my java HTTP server:
public class WebServer implements Runnable {
public static final int PORT = 80;
#Override
public void run() {
HttpServer $server;
try {
$server = HttpServer.create(new InetSocketAddress(80), 0);
} catch (IOException _e) {
throw new RuntimeException(_e);
}
$server.createContext("/", _httpExchange ->
{
String $uri = _httpExchange.getRequestURI().toString();
$uri = $uri.startsWith("/") ? $uri.replaceFirst("/", "") : $uri;
if ($uri.equals("")) {
sendFile("test.html", _httpExchange);
}
else if ($uri.matches(".*\\.[^/.]+")) {
sendFile($uri, _httpExchange);
}
else {
sendFile($uri + ".html", _httpExchange);
}
});
$server.start();
System.out.println("Server started at " + getPrivateIp() + " on port " + PORT);
}
private static String getPrivateIp() {
try (final DatagramSocket datagramSocket = new DatagramSocket()) {
datagramSocket.connect(InetAddress.getByName("8.8.8.8"), 12345);
return datagramSocket.getLocalAddress().getHostAddress();
} catch (UnknownHostException | SocketException _e) {
throw new RuntimeException(_e);
}
}
public static void sendFile(String _name, HttpExchange _exchange) throws IOException {
try {
InputStream $stream = WebServer.class.getResourceAsStream(_name);
if ($stream == null) {
_exchange.sendResponseHeaders(404, 0);
_exchange.close();
return;
}
Scanner $scanner = new Scanner($stream).useDelimiter("\\A");
String $response = $scanner.next();
_exchange.getResponseBody();
_exchange.sendResponseHeaders(200, $response.getBytes().length);
_exchange.getResponseBody().write($response.getBytes());
_exchange.close();
} catch (Exception _ex) {
throw new RuntimeException(_ex);
}
}
}
When I run it, and then open my website, everything is ok, but I cannot see any images. In the network tab, it says that the image was accepted, but it's not shown. I tried using Files.copy() in sendFile() method, but it didn't work - it didn't show the website, nor the image! (Not even when I did localhost/image.jpg).
In the network tab, it also shows that the MIME type is img/jpeg, which is correct, so it's not because of that...
Using wget, I get a normal looking .jpg file, but if I open it, it's corrupted...
Does someone know how to fix this?
Thanks.

Solved it!
You just check if the request wants .png or .jpg file (or you can just check the MIME type), and if it does, then you have to use ImageIO class
public static void sendFile(String _name, HttpExchange _exchange) {
try {
InputStream $stream = WebServer.class.getResourceAsStream(_name);
if ($stream == null) {
_exchange.sendResponseHeaders(404, 0);
_exchange.close();
return;
}
if (_name.matches(".*?\\.(png|PNG|jpg|JPG|jpeg|JPEG)")) {
BufferedImage $image = ImageIO.read($stream);
if (_name.toLowerCase().endsWith("png")) {
_exchange.sendResponseHeaders(200, getImageSize($image, "png"));
ImageIO.write($image, "png", _exchange.getResponseBody());
}
else {
_exchange.sendResponseHeaders(200, getImageSize($image,"jpeg"));
ImageIO.write($image, "jpeg", _exchange.getResponseBody());
}
$stream.close();
_exchange.close();
return;
}
Scanner $scanner = new Scanner($stream).useDelimiter("$");
String $response = $scanner.next();
_exchange.getResponseBody();
_exchange.sendResponseHeaders(200, $response.length());
_exchange.getResponseBody().write($response.getBytes());
_exchange.close();
} catch (Exception _ex) {
throw new RuntimeException(_ex);
}
}

Recursive file search for designated extension

I am using SMBClient to connect to my SMB server with Java.
How can I recursively scan my entire SMB share to get a listing of all files with an .mp4 extension?
This is my code that only scans the one designated directory:
private void btnFileCountActionPerformed(java.awt.event.ActionEvent evt) {
SMBClient client = new SMBClient();
try (Connection connection = client.connect("192.168.X.XXX")) {
AuthenticationContext ac = new AuthenticationContext("XXXXXXX#hotmail.com", "XXXXXX".toCharArray(), "Mastafin");
Session session = connection.authenticate(ac);
try (DiskShare share = (DiskShare) session.connectShare("Folder With Spaces")) {
for (FileIdBothDirectoryInformation f : share.list("LOTS OF SUBDIRS TO SCAN", "*.mp4")) {
System.out.println("File : " + f.getFileName());
}
} catch (Exception e) {
System.out.println(e);
}
} catch (Exception e) {
System.out.println(e);
}
}

Here are some fairly straightforward tweaks to your code to get it to fill an ArrayList recursively. It isn't necessarily the most efficient way of doing this, as it gathers all filenames, and then throws away the ones that don't end with .mp4, but it should give you a straightforward place to start building from.
private void btnFileCountActionPerformed(java.awt.event.ActionEvent evt) {
try (SMBClient client = new SMBClient()) {
try (Connection connection = client.connect(SERVER)) {
AuthenticationContext ac = new AuthenticationContext(USERNAME, PASSWORD.toCharArray(), WORKGROUP);
try (Session session = connection.authenticate(ac)) {
try (DiskShare share = (DiskShare) session.connectShare(SHARE)) {
List<String> files = new ArrayList<>();
listFiles(share, START_DIR, files);
files.removeIf(name -> !name.toLowerCase().endsWith(".mp4"));
files.forEach(System.out::println);
}
}
}
} catch (IOException e) {
e.printStackTrace(System.err);
}
}
private void listFiles(DiskShare share, String path, Collection<String> files) {
List<String> dirs = new ArrayList<>();
String extPath = path.isEmpty() ? path : path + "\\";
for (FileIdBothDirectoryInformation f : share.list(path)) {
if ((f.getFileAttributes() & FileAttributes.FILE_ATTRIBUTE_DIRECTORY.getValue()) != 0) {
if (!isSpecialDir(f.getFileName())) {
dirs.add(f.getFileName());
}
} else {
files.add(extPath + f.getFileName());
}
}
dirs.forEach(dir -> listFiles(share, extPath + dir, files));
}
private static boolean isSpecialDir(String fileName) {
return fileName.equals(".") || fileName.equals("..");
}

Watching a Directory for Changes in Java

I want to watch a directory for file changes. And I used WatchService in java.nio. I can successfully listen for file created event. But I can't listen for file modify event. I checked official java tutorial, but still struggling.
Here is the source code.
import static java.nio.file.LinkOption.NOFOLLOW_LINKS;
import static java.nio.file.StandardWatchEventKinds.ENTRY_CREATE;
import static java.nio.file.StandardWatchEventKinds.OVERFLOW;
import static java.nio.file.StandardWatchEventKinds.ENTRY_DELETE;
import static java.nio.file.StandardWatchEventKinds.ENTRY_MODIFY;
import java.io.File;
import java.io.IOException;
import java.nio.file.FileSystem;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.WatchEvent;
import java.nio.file.WatchEvent.Kind;
import java.nio.file.WatchKey;
import java.nio.file.WatchService;
public class MainWatch {
public static void watchDirectoryPath(Path path) {
// Sanity check - Check if path is a folder
try {
Boolean isFolder = (Boolean) Files.getAttribute(path,
"basic:isDirectory", NOFOLLOW_LINKS);
if (!isFolder) {
throw new IllegalArgumentException("Path: " + path
+ " is not a folder");
}
} catch (IOException ioe) {
// Folder does not exists
ioe.printStackTrace();
}
System.out.println("Watching path: " + path);
// We obtain the file system of the Path
FileSystem fs = path.getFileSystem();
// We create the new WatchService using the new try() block
try (WatchService service = fs.newWatchService()) {
// We register the path to the service
// We watch for creation events
path.register(service, ENTRY_CREATE);
path.register(service, ENTRY_MODIFY);
path.register(service, ENTRY_DELETE);
// Start the infinite polling loop
WatchKey key = null;
while (true) {
key = service.take();
// Dequeueing events
Kind<?> kind = null;
for (WatchEvent<?> watchEvent : key.pollEvents()) {
// Get the type of the event
kind = watchEvent.kind();
if (OVERFLOW == kind) {
continue; // loop
} else if (ENTRY_CREATE == kind) {
// A new Path was created
Path newPath = ((WatchEvent<Path>) watchEvent)
.context();
// Output
System.out.println("New path created: " + newPath);
} else if (ENTRY_MODIFY == kind) {
// modified
Path newPath = ((WatchEvent<Path>) watchEvent)
.context();
// Output
System.out.println("New path modified: " + newPath);
}
}
if (!key.reset()) {
break; // loop
}
}
} catch (IOException ioe) {
ioe.printStackTrace();
} catch (InterruptedException ie) {
ie.printStackTrace();
}
}
public static void main(String[] args) throws IOException,
InterruptedException {
// Folder we are going to watch
// Path folder =
// Paths.get(System.getProperty("C:\\Users\\Isuru\\Downloads"));
File dir = new File("C:\\Users\\Isuru\\Downloads");
watchDirectoryPath(dir.toPath());
}
}

Actually you have incorrectly subscribed to events. Only last listener has been registered with ENTRY_DELETE events type.
To register for all kind of events at once you should use:
path.register(service, ENTRY_CREATE, ENTRY_MODIFY, ENTRY_DELETE);

Warning! Shameless self promotion!
I have created a wrapper around Java 1.7's WatchService that allows registering a directory and any number of glob patterns. This class will take care of the filtering and only emit events you are interested in.
DirectoryWatchService watchService = new SimpleDirectoryWatchService(); // May throw
watchService.register( // May throw
new DirectoryWatchService.OnFileChangeListener() {
#Override
public void onFileCreate(String filePath) {
// File created
}
#Override
public void onFileModify(String filePath) {
// File modified
}
#Override
public void onFileDelete(String filePath) {
// File deleted
}
},
<directory>, // Directory to watch
<file-glob-pattern-1>, // E.g. "*.log"
<file-glob-pattern-2>, // E.g. "input-?.txt"
... // As many patterns as you like
);
watchService.start();
Complete code is in this repo.

I made some classes for this.
public interface FileAvailableListener {
public void fileAvailable(File file) throws IOException;
}
and
public class FileChange {
private long lastModified;
private long size;
private long lastCheck;
public FileChange(File file) {
this.lastModified=file.lastModified();
this.size=file.length();
this.lastCheck = System.currentTimeMillis();
}
public long getLastModified() {
return lastModified;
}
public long getSize() {
return size;
}
public long getLastCheck() {
return lastCheck;
}
public boolean isStable(FileChange other,long stableTime) {
boolean b1 = (getLastModified()==other.getLastModified());
boolean b2 = (getSize()==other.getSize());
boolean b3 = ((other.getLastCheck()-getLastCheck())>stableTime);
return b1 && b2 && b3;
}
}
and
public class DirectoryWatcher {
private Timer timer;
private List<DirectoryMonitorTask> tasks = new ArrayList<DirectoryMonitorTask>();
public DirectoryWatcher() throws URISyntaxException, IOException, InterruptedException {
super();
timer = new Timer(true);
}
public void addDirectoryMonitoringTask(DirectoryMonitorTask task,long period) {
tasks.add(task);
timer.scheduleAtFixedRate(task, 5000, period);
}
public List<DirectoryMonitorTask> getTasks() {
return Collections.unmodifiableList(tasks);
}
public Timer getTimer() {
return timer;
}
}
and
class DirectoryMonitorTask extends TimerTask {
public final static String DIRECTORY_NAME_ARCHIVE="archive";
public final static String DIRECTORY_NAME_ERROR="error";
public final static String LOCK_FILE_EXTENSION=".lock";
public final static String ERROR_FILE_EXTENSION=".error";
public final static String FILE_DATE_FORMAT="yyyyMMddHHmmssSSS";
private String name;
private FileAvailableListener listener;
private Path directory;
private File directoryArchive;
private File directoryError;
private long stableTime;
private FileFilter filter;
private WatchService watchService;
private SimpleDateFormat dateFormatter = new SimpleDateFormat(FILE_DATE_FORMAT);
private Hashtable<File,FileChange> fileMonitor = new Hashtable<File,FileChange>();
public DirectoryMonitorTask(String name,FileAvailableListener listener,Path directory,long stableTime,FileFilter filter) throws IOException {
super();
this.name=name;
this.listener=listener;
this.directory=directory;
this.stableTime=stableTime;
if (stableTime<1) {
stableTime=1000;
}
this.filter=filter;
validateNotNull("Name",name);
validateNotNull("Listener",listener);
validateNotNull("Directory",directory);
validate(directory);
directoryArchive = new File(directory.toFile(),DIRECTORY_NAME_ARCHIVE);
directoryError = new File(directory.toFile(),DIRECTORY_NAME_ERROR);
directoryArchive.mkdir();
directoryError.mkdir();
//
log("Constructed for "+getDirectory().toFile().getAbsolutePath());
initialize();
//
watchService = FileSystems.getDefault().newWatchService();
directory.register(watchService,StandardWatchEventKinds.ENTRY_CREATE,StandardWatchEventKinds.ENTRY_DELETE,StandardWatchEventKinds.ENTRY_MODIFY);
log("Started");
}
private void initialize() {
File[] files = getDirectory().toFile().listFiles();
for (File file : files) {
if (isLockFile(file)) {
file.delete();
} else if (acceptFile(file)) {
fileMonitor.put(file,new FileChange(file));
log("Init file added -"+file.getName());
}
}
}
public SimpleDateFormat getDateFormatter() {
return dateFormatter;
}
public Path getDirectory() {
return directory;
}
public FileAvailableListener getListener() {
return listener;
}
public String getName() {
return name;
}
public WatchService getWatchService() {
return watchService;
}
public long getStableTime() {
return stableTime;
}
public File getDirectoryArchive() {
return directoryArchive;
}
public File getDirectoryError() {
return directoryError;
}
public FileFilter getFilter() {
return filter;
}
public Iterator<File> getMonitoredFiles() {
return fileMonitor.keySet().iterator();
}
#Override
public void run() {
WatchKey key;
try {
key = getWatchService().take();
// Poll all the events queued for the key
for (WatchEvent<?> event : key.pollEvents()) {
#SuppressWarnings("unchecked")
Path filePath = ((WatchEvent<Path>) event).context();
File file = filePath.toFile();
if ((!isLockFile(file)) && (acceptFile(file))) {
switch (event.kind().name()) {
case "ENTRY_CREATE":
//
fileMonitor.put(file,new FileChange(file));
log("File created ["+file.getName()+"]");
break;
//
case "ENTRY_MODIFY":
//
fileMonitor.put(file,new FileChange(file));
log("File modified ["+file.getName()+"]");
break;
//
case "ENTRY_DELETE":
//
log("File deleted ["+file.getName()+"]");
createLockFile(file).delete();
fileMonitor.remove(file);
break;
//
}
}
}
// reset is invoked to put the key back to ready state
key.reset();
} catch (InterruptedException e) {
e.printStackTrace();
}
Iterator<File> it = fileMonitor.keySet().iterator();
while (it.hasNext()) {
File file = it.next();
FileChange fileChange = fileMonitor.get(file);
FileChange fileChangeCurrent = new FileChange(file);
if (fileChange.isStable(fileChangeCurrent, getStableTime())) {
log("File is stable ["+file.getName()+"]");
String filename = getDateFormatter().format(new Date())+"_"+file.getName();
File lockFile = createLockFile(file);
if (!lockFile.exists()) {
log("File do not has lock file ["+file.getName()+"]");
try {
Files.createFile(lockFile.toPath());
log("Processing file ["+file.getName()+"]");
getListener().fileAvailable(file);
file.renameTo(new File(getDirectoryArchive(),filename));
log("Moved to archive file ["+file.getName()+"]");
} catch (IOException e) {
file.renameTo(new File(getDirectoryError(),filename));
createErrorFile(file,e);
log("Moved to error file ["+file.getName()+"]");
} finally {
lockFile.delete();
}
} else {
log("File do has lock file ["+file.getName()+"]");
fileMonitor.remove(file);
}
} else {
log("File is unstable ["+file.getName()+"]");
fileMonitor.put(file,fileChangeCurrent);
}
}
}
public boolean acceptFile(File file) {
if (getFilter()!=null) {
return getFilter().accept(file);
} else {
return true;
}
}
public boolean isLockFile(File file) {
int pos = file.getName().lastIndexOf('.');
String extension="";
if (pos!=-1) {
extension = file.getName().substring(pos).trim().toLowerCase();
}
return(extension.equalsIgnoreCase(LOCK_FILE_EXTENSION));
}
private File createLockFile(File file) {
return new File(file.getParentFile(),file.getName()+LOCK_FILE_EXTENSION);
}
private void createErrorFile(File file,IOException exception) {
File errorFile = new File(file.getParentFile(),file.getName()+ERROR_FILE_EXTENSION);
StringWriter sw = null;
PrintWriter pw = null;
FileWriter fileWriter = null;
try {
//
fileWriter = new FileWriter(errorFile);
if (exception!=null) {
sw = new StringWriter();
pw = new PrintWriter(sw);
exception.printStackTrace(pw);
fileWriter.write(sw.toString());
} else {
fileWriter.write("Exception is null.");
}
//
fileWriter.flush();
//
} catch (IOException e) {
} finally {
if (sw!=null) {
try {
sw.close();
} catch (IOException e1) {
}
}
if (pw!=null) {
pw.close();
}
if (fileWriter!=null) {
try {
fileWriter.close();
} catch (IOException e) {
}
}
}
}
private void validateNotNull(String name,Object obj) {
if (obj==null) {
throw new NullPointerException(name+" is null.");
}
}
private void validate(Path directory) throws IOException {
File file = directory.toFile();
if (!file.exists()) {
throw new IOException("Directory ["+file.getAbsolutePath()+"] do not exists.");
} else if (!file.isDirectory()) {
throw new IOException("Directory ["+file.getAbsolutePath()+"] is not a directory.");
} else if (!file.canRead()) {
throw new IOException("Can not read from directory ["+file.getAbsolutePath()+"].");
} else if (!file.canWrite()) {
throw new IOException("Can not write to directory ["+file.getAbsolutePath()+"] .");
}
}
private void log(String msg) {
//TODO
System.out.println("Task ["+getName()+"] "+msg);
}
}

package p1;
import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import static java.nio.file.LinkOption.NOFOLLOW_LINKS;
import java.nio.file.StandardWatchEventKinds;
import java.nio.file.WatchEvent;
import java.nio.file.WatchKey;
import java.nio.file.WatchService;
import java.util.List;
public class WatchForFile {
public void WatchMyFolder(String path )
{
File dir = new File(path);
Path myDir= dir.toPath();
try
{
Boolean isFolder = (Boolean) Files.getAttribute(myDir,"basic:isDirectory", NOFOLLOW_LINKS);
if (!isFolder)
{
throw new IllegalArgumentException("Path: " + myDir + " is not a folder");
}
}
catch (IOException ioe)
{
ioe.printStackTrace();
}
System.out.println("Watching path: " + myDir);
try {
WatchService watcher = myDir.getFileSystem().newWatchService();
myDir.register(watcher, StandardWatchEventKinds.ENTRY_CREATE,StandardWatchEventKinds.ENTRY_DELETE, StandardWatchEventKinds.ENTRY_MODIFY);
WatchKey watckKey = watcher.take();
List<WatchEvent<?>> events = watckKey.pollEvents();
for (WatchEvent event : events) {
if (event.kind() == StandardWatchEventKinds.ENTRY_CREATE) {
System.out.println("Created: " + event.kind().toString());
}
if (event.kind() == StandardWatchEventKinds.ENTRY_DELETE) {
System.out.println("Delete: " + event.context().toString());
}
if (event.kind() == StandardWatchEventKinds.ENTRY_MODIFY) {
System.out.println("Modify: " + event.context().toString());
}
}
}
catch (Exception e)
{
System.out.println("Error: " + e.toString());
}
}
}

Check this Code...
https://github.com/omkar9999/FileWatcherHandler
This project allows watching files for different file events like create, modify & delete and then act on these events in a generic way.
How to Use?
Create a Path object representing the directory to monitor for file events.
Path path = Paths.get("/home/omkar/test");
Implement the FileHandler interface to perform an action detected by file event registered.
public class FileHandlerTest implements FileHandler {
private static final Logger LOGGER = Logger.getLogger(FileHandlerTest.class.getName());
/*
* This implemented method will delete the file
*
* #see com.io.util.FileHandler#handle(java.io.File,
* java.nio.file.WatchEvent.Kind)
*/
public void handle(File file, Kind<?> fileEvent) {
LOGGER.log(Level.INFO,"Handler is triggered for file {0}",file.getPath());
if(fileEvent == StandardWatchEventKinds.ENTRY_CREATE) {
try {
boolean deleted = Files.deleteIfExists(Paths.get(file.getPath()));
assertTrue(deleted);
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
Create an instance of an Implemented FileHandler
FileHandlerTest fileHandlerTest = new FileHandlerTest();
Create an instance of a FileWatcher by passing path, an instance of an Implemented FileHandler, and types of file events that you want to monitor separated by commas.
FileWatcher fileWatcher = new FileWatcher(path, fileHandlerTest, StandardWatchEventKinds.ENTRY_CREATE);
Now Create and start a new Thread.
Thread watcherThread = new Thread(fileWatcher);
watcherThread.start();
This thread will start polling for your registered file events and will invoke your custom handle method once any of the registered events are detected.

public class FileWatcher implements Runnable {
private static final Logger LOGGER =Logger.getLogger(FileWatcher.class.getName());
private WatchService watcher;
private FileHandler fileHandler;
private List<Kind<?>> watchedEvents;
private Path directoryWatched;
/**
* #param directory
* #Path directory to watch files into
* #param fileHandler
* #FileHandler implemented instance to handle the file event
* #param watchRecursive
* if directory is to be watched recursively
* #param watchedEvents
* Set of file events watched
*
* #throws IOException
*/
public FileWatcher(Path directory, FileHandler fileHandler, boolean watchRecursive,
WatchEvent.Kind<?>... watchedEvents) throws IOException {
super();
this.watcher = FileSystems.getDefault().newWatchService();
this.fileHandler = fileHandler;
this.directoryWatched = directory;
this.watchedEvents = Arrays.asList(watchedEvents);
if (watchRecursive) {
// register all subfolders
Files.walkFileTree(directory, new SimpleFileVisitor<Path>() {
#Override
public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) throws IOException {
LOGGER.log(Level.INFO, "Registering {0} ", dir);
dir.register(watcher, StandardWatchEventKinds.ENTRY_CREATE, StandardWatchEventKinds.ENTRY_DELETE,
StandardWatchEventKinds.ENTRY_MODIFY);
return FileVisitResult.CONTINUE;
}
});
} else {
directory.register(watcher, watchedEvents);
}
}
#SuppressWarnings({ "unchecked" })
public void run() {
LOGGER.log(Level.INFO, "Starting FileWatcher for {0}", directoryWatched.toAbsolutePath());
WatchKey key = null;
while (true) {
try {
key = watcher.take();
if (key != null) {
for (WatchEvent<?> event : key.pollEvents()) {
WatchEvent.Kind<?> kind = event.kind();
WatchEvent<Path> ev = (WatchEvent<Path>) event;
//directory in which file event is detected
Path directory = (Path) key.watchable();
Path fileName = ev.context();
if (watchedEvents.contains(kind)) {
LOGGER.log(Level.INFO, "Invoking handle on {0}", fileName.toAbsolutePath());
fileHandler.handle(directory.resolve(fileName).toFile(), kind);
}
}
key.reset();
}
} catch (InterruptedException ex) {
LOGGER.log(Level.SEVERE, "Polling Thread was interrupted ", ex);
Thread.currentThread().interrupt();
}
}
}
}

unable to fetch process time using sigar

import java.io.IOException;
import org.hyperic.sigar.*;
public class SigarDemo {
public static void main(String args[]) throws SigarException, IOException
{
final Sigar sigar = new Sigar();
final long[] processes = sigar.getProcList();
ProcTime pt=new ProcTime();
for (final long processId : processes) {
ProcUtil.getDescription(sigar, processId);
pt=sigar.getProcTime(processId);
System.out.println("---"+pt.getStartTime());
}
}
I am trying to fetch process time of each process using sigar. I am getting this errors:
Exception in thread "main" java.lang.ExceptionInInitializerError
at taskmanager.SigarDemo.main(SigarDemo.java:22)
Caused by: java.security.AccessControlException: access denied ("java.util.PropertyPermission" "sigar.nativeLogging" "read")
at java.security.AccessControlContext.checkPermission(AccessControlContext.java:457)
at java.security.AccessController.checkPermission(AccessController.java:884)
at java.lang.SecurityManager.checkPermission(SecurityManager.java:549)
at java.lang.SecurityManager.checkPropertyAccess(SecurityManager.java:1294)
at java.lang.System.getProperty(System.java:714)
at org.hyperic.sigar.Sigar.(Sigar.java:78)
I have tried policy file setting all permission. but still I am getting errors. I am using netbeans 8.0 . and I had already setting
-Djava.security.manager -Djava.security.policy=src/dir1/dir2/important.policy

I used this code to get the process times
public static void main(String args[]) {
try {
final Sigar sigar = new Sigar();
final long[] processes = sigar.getProcList();
ProcTime pt = new ProcTime();
for (final long processId : processes) {
try {
ProcUtil.getDescription(sigar, processId);
pt = sigar.getProcTime(String.valueOf(processId));
System.out.println("---" + pt.getStartTime());
} catch (SigarException e) {
System.out.println("can't accessible...");
}
}
} catch (SigarException ex) {
ex.printStackTrace();
}
}
you don't want to specify the security policy file in VM arguments to get the process times. but the thing is getProcTime() will not return process times for some process ids because of SigarPermissionDeniedException.
but you will get process time for some processes without any problem.
I got this idea from a sample demo file from bindings\java\examples folder. I posted it below with slight modification. you can compile and run it to see the result(it includes the process time also)
import org.hyperic.sigar.Sigar;
import org.hyperic.sigar.SigarProxy;
import org.hyperic.sigar.SigarException;
import org.hyperic.sigar.ProcCredName;
import org.hyperic.sigar.ProcMem;
import org.hyperic.sigar.ProcTime;
import org.hyperic.sigar.ProcState;
import org.hyperic.sigar.ProcUtil;
import org.hyperic.sigar.cmd.Shell;
import org.hyperic.sigar.cmd.SigarCommandBase;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.text.SimpleDateFormat;
import java.util.Date;
/**
* Show process status.
*/
public class Ps extends SigarCommandBase {
public Ps(Shell shell) {
super(shell);
}
public Ps() {
super();
}
protected boolean validateArgs(String[] args) {
return true;
}
public String getSyntaxArgs() {
return "[pid|query]";
}
public String getUsageShort() {
return "Show process status";
}
public boolean isPidCompleter() {
return true;
}
public void output(String[] args) throws SigarException {
long[] pids;
if (args.length == 0) {
pids = this.proxy.getProcList();
}
else {
pids = this.shell.findPids(args);
}
for (int i=0; i<pids.length; i++) {
long pid = pids[i];
try {
output(pid);
} catch (SigarException e) {
this.err.println("Exception getting process info for " +
pid + ": " + e.getMessage());
}
}
}
public static String join(List info) {
StringBuffer buf = new StringBuffer();
Iterator i = info.iterator();
boolean hasNext = i.hasNext();
while (hasNext) {
buf.append((String)i.next());
hasNext = i.hasNext();
if (hasNext)
buf.append("\t");
}
return buf.toString();
}
public static List getInfo(SigarProxy sigar, long pid)
throws SigarException {
ProcState state = sigar.getProcState(pid);
ProcTime time = null;
String unknown = "???";
List info = new ArrayList();
info.add(String.valueOf(pid));
try {
ProcCredName cred = sigar.getProcCredName(pid);
info.add(cred.getUser());
} catch (SigarException e) {
info.add(unknown);
}
try {
time = sigar.getProcTime(pid);
info.add(getStartTime(time.getStartTime()));
System.out.println("this line has executed..!!!");
} catch (SigarException e) {
info.add(unknown);
}
try {
ProcMem mem = sigar.getProcMem(pid);
info.add(Sigar.formatSize(mem.getSize()));
info.add(Sigar.formatSize(mem.getRss()));
info.add(Sigar.formatSize(mem.getShare()));
} catch (SigarException e) {
info.add(unknown);
}
info.add(String.valueOf(state.getState()));
if (time != null) {
info.add(getCpuTime(time));
}
else {
info.add(unknown);
}
String name = ProcUtil.getDescription(sigar, pid);
info.add(name);
return info;
}
public void output(long pid) throws SigarException {
println(join(getInfo(this.proxy, pid)));
}
public static String getCpuTime(long total) {
long t = total / 1000;
return t/60 + ":" + t%60;
}
public static String getCpuTime(ProcTime time) {
return getCpuTime(time.getTotal());
}
private static String getStartTime(long time) {
if (time == 0) {
return "00:00";
}
long timeNow = System.currentTimeMillis();
String fmt = "MMMd";
if ((timeNow - time) < ((60*60*24) * 1000)) {
fmt = "HH:mm";
}
return new SimpleDateFormat(fmt).format(new Date(time));
}
public static void main(String[] args) throws Exception {
new Ps().processCommand(args);
}
}

Establishing WebSocket connection with Java server and Javascript client

I'm trying to implement WebSockets with a Javascript-based client and a Java-based server. I think I've done all the correct steps, but for an unknown reason, I can't establish the connection with both.
When the server socket receives a connection, it handles to form a websocket-accept response, and it sends back to the client, but the connection in the client socket instantly close, weird that there's no handshake problem.
Does anyone have an idea what might be the problem?
Here's my server code implemented in java:
package server;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.ArrayList;
import java.util.List;
import server.message.Message;
import server.message.SpeakMessage;
public class Server implements ConnectionListener {
private static final int PORT = 1509;
private MessageDispatcher dispatcher = new MessageDispatcher();
private List<ConnectionManager> clients = new ArrayList<>();
public void listen() {
try (ServerSocket server = new ServerSocket(PORT)) {
System.out.printf("Listening on port %d...%n", PORT);
while (true) {
System.out.println("Waiting for connection...");
Socket client = server.accept();
System.out.println("Incoming connection - Attempting to establish connection...");
ConnectionManager manager = new ConnectionManager(client, dispatcher, this);
manager.start();
}
} catch (IOException e) {
System.out.println("Unable to start server");
e.printStackTrace();
}
System.exit(0);
}
public void execute() {
try {
while (true) {
if (dispatcher.isEmpty()) {
Thread.sleep(100);
continue;
}
Message msg = dispatcher.read();
if (msg instanceof SpeakMessage)
broadcast(MessageEncoder.spoke(((SpeakMessage) msg).getText()));
}
} catch (Exception e) {
e.printStackTrace();
System.exit(1);
}
}
public static void main(String[] args) {
final Server server = new Server();
new Thread(new Runnable() {
#Override
public void run() {
server.listen();
}
}).start();
server.execute();
}
public synchronized void broadcast(byte[] message) {
for (ConnectionManager client : clients) {
client.send(message);
}
}
#Override
public synchronized void clientConnected(ConnectionManager who) {
clients.add(who);
System.out.println("Connected client " + clients.size());
}
#Override
public synchronized void clientDisconnected(ConnectionManager who) {
clients.remove(who);
}
}
Heres subclass ConnectionManager of server:
package server;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.InvocationTargetException;
import java.net.Socket;
import java.security.MessageDigest;
import java.util.Properties;
import server.message.HandshakeMessage;
import server.message.Message;
public class ConnectionManager {
private static final int CLIENT_VERSION = 1;
private Socket socket;
private MessageDecoder decoder = new MessageDecoder();
private MessageDispatcher dispatcher;
private ConnectionListener listener;
public ConnectionManager(Socket connection, MessageDispatcher dispatcher, ConnectionListener listener) {
socket = connection;
this.dispatcher = dispatcher;
this.listener = listener;
}
public void start() {
Thread t = new Thread(new ChannelReader());
t.setName("Client thread");
t.setDaemon(true);
t.start();
}
public void send(byte[] data) {
if (socket == null)
return;
try {
DataOutputStream dos = new DataOutputStream(socket.getOutputStream());
dos.write(data);
dos.flush();
} catch (IOException e) {
disconnect("Client closed the connection");
}
}
private class ChannelReader implements Runnable {
private boolean accepted = false;
private String ret = null;
#Override
public void run() {
try {
DataInputStream in = new DataInputStream(socket.getInputStream());
while (socket != null && socket.isConnected()) {
int len = in.readShort();
if (len < 0) {
disconnect("Invalid message length.");
}
String s;
readLine(in);
Properties props = new Properties();
while((s=readLine(in)) != null && !s.equals("")) {
String[] q = s.split(": ");
props.put(q[0], q[1]);
}
if(props.get("Upgrade").equals("websocket") && props.get("Sec-WebSocket-Version").equals("13")) { // check if is websocket 8
String key = (String) props.get("Sec-WebSocket-Key");
String r = key + "" + "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"; // magic key
MessageDigest md = MessageDigest.getInstance("SHA-1");
md.reset();
md.update(r.getBytes());
byte[] sha1hash = md.digest();
String returnBase = base64(sha1hash);
ret = "HTTP/1.1 101 Switching Protocols\r\n";
ret+="Upgrade: websocket\r\n";
ret+="Connection: Upgrade\r\n";
ret+="Sec-WebSocket-Accept: "+returnBase;
} else {
disconnect("Client got wrong version of websocket");
}
Message msg = decoder.decode((String) props.get("Sec-WebSocket-Protocol"));
if (!accepted) {
doHandshake(msg);
} else if (dispatcher != null) {
dispatcher.dispatch(msg);
}
}
} catch (Exception e) {
disconnect(e.getMessage());
e.printStackTrace();
}
}
private void doHandshake(Message msg) {
if (!(msg instanceof HandshakeMessage)) {
disconnect("Missing handshake message");
return;
}
HandshakeMessage handshake = (HandshakeMessage) msg;
if (handshake.getVersion() != CLIENT_VERSION) {
disconnect("Client failed in handshake.");
return;
}
send(ret.getBytes());
accepted = true;
listener.clientConnected(ConnectionManager.this);
}
private String base64(byte[] input) throws ClassNotFoundException,
SecurityException, NoSuchMethodException, IllegalArgumentException,
IllegalAccessException, InvocationTargetException, InstantiationException {
Class<?> c = Class.forName("sun.misc.BASE64Encoder");
java.lang.reflect.Method m = c.getMethod("encode", new Class<?>[]{byte[].class});
String s = (String) m.invoke(c.newInstance(), input);
return s;
}
private String readLine(InputStream in) {
try{
String line = "";
int pread;
int read = 0;
while(true) {
pread = read;
read = in.read();
if(read!=13&&read!=10)
line += (char) read;
if(pread==13&&read==10) break;
}
return line;
}catch(IOException ex){
}
return null;
}
}
public synchronized void disconnect(String message) {
System.err.println(message);
if (socket != null) {
try {
socket.close();
} catch (IOException e) {
}
}
socket = null;
listener.clientDisconnected(ConnectionManager.this);
}
}
And the MessageDispatcher:
package server;
import java.util.Queue;
import java.util.concurrent.LinkedBlockingDeque;
import server.message.Message;
public class MessageDispatcher {
Queue<Message> messageQueue = new LinkedBlockingDeque<>();
public void dispatch(Message message) {
messageQueue.offer(message);
}
public Message read() {
return messageQueue.poll();
}
public boolean isEmpty() {
return messageQueue.isEmpty();
}
}
And heres my client code implemented in javascript:
var canvas, // Canvas DOM element
ctx, // Canvas rendering context
socket; // Socket connection
function init() {
// Initialise the canvas
canvas = document.getElementById("gameCanvas");
ctx = canvas.getContext("2d");
// Maximise the canvas
canvas.width = window.innerWidth;
canvas.height = window.innerHeight;
// Initialise socket connection
if (window.WebSocket) {
socket = new WebSocket("ws://localhost:1509/", ["1", "YURI"]);
socket.onopen = onSocketConnected();
socket.onclose = onSocketDisconnect();
socket.onmessage = onSocketMessage();
socket.onerror = onSocketError();
} else {
alert("The browser does not support websocket.");
}
};
// Socket message
function onSocketMessage(message) {
console.log('Message: ' + message.data);
};
// Socket error
function onSocketError(error) {
console.log('Error: ' + error.data);
};
// Socket connected
function onSocketConnected() {
console.log("Connected to socket server");
};
// Socket disconnected
function onSocketDisconnect() {
console.log("Disconnected from socket server");
};

I think, it is because you are using the Socket Package on the Java Server Side and the WebSocket API on the Client Side. Your idea is really good but the wrong technology.
Keep the WebSocket on the Client Side (Javascript) becaue you don't have lots of other possibilities, but try JWebSocket on the Server side (Java). In Fact WebSocket is using TCP/IP but its own communication protocol over TCP/IP. The Java Socket Package is purely TCP/IP. Re-write your server with JWebSocket, all details about JWebSocket can be found at:
http://jwebsocket.org/.
I hope my answer will help you.

you must specify end of return packet with "\r\n\r\n"
ret = "HTTP/1.1 101 Switching Protocols\r\n";
ret+="Upgrade: websocket\r\n";
ret+="Connection: Upgrade\r\n";
ret+="Sec-WebSocket-Accept: "+returnBase + "\r\n\r\n";
and for create accept key i use
public class WSKeyGenerator {
private final static String MAGIC_KEY =
"258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
public static String getKey(String strWebSocketKey) throws
NoSuchAlgorithmException {
strWebSocketKey += MAGIC_KEY;
MessageDigest shaMD = MessageDigest.getInstance("SHA-1");
shaMD.reset();
shaMD.update(strWebSocketKey.getBytes());
byte messageDigest[] = shaMD.digest();
BASE64Encoder b64 = new BASE64Encoder();
return b64.encode(messageDigest);
}
}
I recommend that use the http://websocket.org/echo.html to check the server's websocket functionality