I have this printService snippet written :
public class MainTest {
public static void main(String[] args) {
DocFlavor flavor = DocFlavor.SERVICE_FORMATTED.PRINTABLE;
//PrintService defPrnSrvc = PrintServiceLookup.lookupDefaultPrintService();
PrintRequestAttributeSet aset = new HashPrintRequestAttributeSet();
PrintService[] services = PrintServiceLookup.lookupPrintServices(null, null);
System.out.println("my printer found: " + services.length);
// this step is necessary because I have several printers configured
for (int i = 0; i < services.length; i++) {
String svcName = services[i].toString();
//
}
}
}
But when I host it in heroku, it does not show any printer, I know the reason, that the printer service looks in your local system, thus it wont work on heroku, but is there a workaround to this, like if I send some details from my local, like IP address or Mac address of my computer then it can search the printers in that computer?
Is there a way how to pass parameters to printservice class to get the printers of a particular computer? Or does it always looks in localhost.
Interesting. I don't think Heroku has plugins for connecting to local devices in a given location, but here's a couple of ideas:
If your printer is cloud enabled, you can check the manufacturer docs of the printer to see whether there's a way to connect remotely. Probably involves flipping a setting on the printer(s) itself too.
Have you looked into Google's project for this, and does it work for your use case? https://www.google.com/cloudprint/#printers
This is the long way around, but you could probably hook up a Raspberry Pi to the printer, and use it to host an API endpoint so the pi can receive document data and any instructions you need, then pass it to the local printer via the local connection.
Hope this helps!
Related
I'm testing PHP/Java Bridge connection. And I have a simple example yet.
The php file is:
require_once("http://localhost:8087/JavaBridge/java/Java.inc");
$world = new java("HelloWorld");
echo $world->hello(array("from PHP"));
And the java file:
import javax.swing.JOptionPane;
public class HelloWorld {
public static final String JAVABRIDGE_PORT="8087";
static final php.java.bridge.JavaBridgeRunner runner =
php.java.bridge.JavaBridgeRunner.getInstance(JAVABRIDGE_PORT);
public static void main(String args[]) throws Exception {
runner.waitFor();
System.exit(0);
}
public void hello(String args[]) throws Exception {
JOptionPane.showMessageDialog(null, "hello " + args[0]);
}
}
Everything works fine on one pc. But I have to implement connection from PHP server to java desktop application which is on the another server not on localhost, so "localhost:8087/JavaBridge/java/Java.inc" won't work. In future this java app will print on printer some data from php website.
So I need to call java function remotely. It should be a desktop App because I will write usb connection in future. Please help me, thanks.
You can't use require_once to include files from another host.
If this option is available, a lot of websites will be at risk.
Why don't you use it from another way, Here are some points that may help:
make java calls PHP.
write your result to some file in the destination server.
Make server reads that file.
If you don't like that, please read about web service, it may have what you need.
I have been working on this project where two modules on different machines need to be in communication through RMI.
I start both client and server modules on my laptop. RMI seems to work correctly when i am at work and connected to work network, but when i am home, connected to my home network it does not work. It says remote object could not be found.
Here is the method i use at CLIENT side to get the reference to remote object
public static MyRMIApp getRemoteApp() throws RemoteException, NotBoundException, AccessException {
Registry registry = LocateRegistry.getRegistry("localhost", 28999); // tried 127.0.0.1 instead of localhost here, still not working
MyRMIApp app = (MyRMIApp) registry.lookup("COM");
return app;
}
Digging up a bit with some debugging, when i check the object value returned from getRemoteApp method, it shows me the end point is 67.215.65.132. Which is openDNS i am using to connect to internet. Shouldn't that be 127.0.0.1 ?
Then i used my mobile internet and tried again. It seems to be working but end-point is not 127.0.0.1 again it is the address assigned to me, which is 192.168.x.x
So can anybody please tell me what is wrong i am doing here ? I really would appreciate the help.
Oh and this is the piece of code at SERVER side
//Somwhere up top
private final static MyRMIApp rmiApp = new RMIServer();
//Down below
MyRMIApp stub = (MyRMIApp) UnicastRemoteObject.exportObject(rmiApp, 0);
Registry registry = LocateRegistry.createRegistry(28999);
registry.rebind("COM", stub);
See item A.1 of the RMI FAQ: specifically, 'The appropriate workaround is to set the system property java.rmi.server.hostname when starting the server.'
I have a desktop application built with jdk 6 which publishes web services to be consumed by a web application. So far I've had no problem while both applications are running in the same physical computer, i can access the wsdl without any problem and the web application works with the desktop application just fine. The thing is I cannot access to the services from a remote computer in the same network. The two PCs are connected and can interact. If I run both applications in PC1, from PC2 I can use the webapp through
http://PC1:8080
I am currently publishing like this:
public Publicador(){
servicios= new Servicios();
Endpoint endpoint = Endpoint.publish("http://PC1:8686/servicios", servicios);
}
where PC1 is the name of the pc. From PC1, i can see the generated wsdl from the following address, and it's the one I used for the wsimport command:
http://PC1:8686/servicios?wsdl
But I cannnot from PC2.
Any ideas why it is not visible from outside PC1?
Incredible as it may seem, I found the simplest of answers... Instead of publishing as
Endpoint endpoint = Endpoint.publish("http://PC1:8686/servicios", servicios);
I published as
Endpoint endpoint = Endpoint.publish("http://0.0.0.0:8686/servicios", servicios);
and that solved it...
Another solution was to get the address to publish from a file, that worked too. I don't know why it didn't hardcoded... I ended up doing it like this:
Properties prop = new Properties();
InputStream is = null;
String currenDir = System.getProperty("user.dir");
String nombreArchivo = currenDir + File.separator + "ubicacion.PROPERTIES";
try {
is=new FileInputStream(nombreArchivo);
prop.load(is);
} catch(IOException ioe) {}
String pc = prop.getProperty("ServiciosWeb");
Endpoint endpoint = Endpoint.publish( pc, servicios);
}
I'm trying to test my code that reads from a USB port (COM25 when the device is connected) that is created when a device is connected to my computer and to a boat. I cannot power the USB device when not on the boat so testing is difficult. Can someone let me know how to simulate a COM port and write data to it so my test program is able to connect to that simulated COM port and read that data?
I'm reading this from a Java program but the simulation doesn't need to be in Java or any specific language. Just a program that will simulate the COM port and allow me to connect to it. I downloaded a COM port emulator from AGG Software and it appears that it's writing to what I deem COM25 but I'm not able to connect to it from my Java test.
The general answer for this kind of problem is to wrap the code that talks to the COM port in a class that implements an interface. If you do this as a Facade (pattern) then you can also make the COM methods you call sensible from your end.
The interface can then be mocked or faked for the test. (There is a great article on test objects, but I haven't been able to find it yet.) One advantage here is that you can create a fake version that throws exceptions or otherwise does things that are possible for the port to do but hard to get it to do in practice.
Where I work, we solved a similar issue by having our emulator not spoof a COM port at all. Here's how you can do it:
Define an interface for talking with your COM port, something like IUsbCommService
Implement your real COM-communcation service, using the standard Java Comm API
For your emulator, simply kick of a thread that spits out the same sort of data you can expect from your USB device at regular intervals.
Use your IOC framework of choice (e.g., Spring) to wire up either the emulator or the real service.
As long as you hide your implementation logic appropriately, and as long as you code to your interface, your service-consumer code won't care whether it's talking to the real USB device or to the emulator.
For example:
import yourpackage.InaccessibleDeviceException;
import yourpackage.NoDataAvailableException;
public interface IUsbProviderService {
public void initDevice() throws InaccessibleDeviceException;
public UsbData getUsbData()
throws InaccessibleDeviceException, NoDataAvailableException;
}
// The real service
import javax.comm.SerialPort; //....and the rest of the java comm API
public class UsbService implements IUsbProviderService {
.
.
.
}
// The emulator
public class UsbServiceEmulator implements IUsbProviderService {
private Thread listenerThread;
private static final Long WAITTIMEMS = 10L;
private String usbData;
public UsbServiceEmulator(long maxWaitTime) throws InaccessibleDeviceException{
initialize();
boolean success = false;
long slept = 0;
while (!success && slept < maxWaitTime) {
Thread.sleep(WAITTIMEMS);
slept += WAITTIMEMS;
}
}
private void initialize() throws InaccessibleDeviceException{
listenerThread = new Thread();
listenerThread.start();
}
private class UsbRunner implements Runnable {
private String[] lines = {"Data line 1", "Data line 2", "Data line 3"};
public void run() {
int line = 0;
while(true) {
serialEvent(lines[line]);
if(line == 3) {
line = 0;
} else {
line++;
}
try {
Thread.sleep(200);
} catch (InterruptedException e) {
//handle the error
}
}
private void serialEvent(String line) {
if(/*you have detected you have enough data */) {
synchronized(this) {
usbData = parser.getUsbData();
}
}
}
}
Hope this helps!
Thanks to all the answers so far! Here's what I ended up doing as a result of recommendations from someone at work.
Downloaded the COM Port Data Emulator (CPDE) from AGG Software
Downloaded the Virtual Serial Port Driver (VSPD) from Eltima Software
(I just randomly picked a free data emulator and virtual serial port package. There are plenty of alternatives out there)
Using VSPD, created virtual serial ports 24 and 25 and connected them via a virtual null modem cable. This effectively creates a write port at 24 and a read port at 25.
Ran the CPDE, connected to 24 and started writing my test data.
Ran my test program, connected to 25 and was able to read the test data from it
There are plenty of relevant answers in this section. But as for me, I personally use Virtual Serial Port Driver, which works perfect for me. But I must admit that there are plenty alternatives when it comes to creating virtual ports: freevirtualserialports.com; comOcom to name a few. But I haven't got a chance to use them, so my recommendation for solving this problem is Virtual Serial Port Driver.
I recommend fabulatech's virtual modem.
Get it at http://www.virtual-modem.com
You might also want to get a COM port monitor for your tests - You can find it at
http://www.serial-port-monitor.com
Good luck with the boat! :)
I use com0com and it works great for what I need.
In addition all others, I would like to added this nice, free emulator https://sites.google.com/site/terminalbpp/ I do use. I do also use AGG Com port data emulator.
I am working on an application that will sport a web-based point of sale interface.
The point of sale PC (I am not sure as of now whether it will run on Linux or Windows) must have a fiscal printer attached to it, but like any web app, it is the server which processes all stuff. Both server and PoS machines are on the same LAN.
I must send the sale data in real time, and via the fiscal printer which uses the serial port, so printing a PDF or even a web page is not an option.
I've been told I could have a little app listening on web services on the client, which in turn talks to the printer instead of the server or the browser, but don't have a clue how to do it. Also, I'll most likely need to listen to any printer feedback (coupon number, for instance, which is generated by the printer) and hand it back to the server.
Any ideas?
I did something similar to this a couple of yrs. ago. But in my case the server and the PC where in the same lan. Is your PoS within the lan? If so, I'll explain it to you.
In the mean time, if you have the "little app" covered you can take a look at the following:
http://java.sun.com/j2se/1.4.2/docs/api/javax/print/PrintService.html
The print service have a method to discover the printers registered within machine it is running on. So after you receive the message from the server on your app you just have to do something similar to the code shown in the link above:
Taked from, http://java.sun.com/j2se/1.4.2/docs/api/javax/print/PrintService.html
DocFlavor flavor = DocFlavor.INPUT_STREAM.POSTSCRIPT;
PrintRequestAttributeSet aset = new HashPrintRequestHashAttributeSet();
aset.add(MediaSizeName.ISO_A4);
PrintService[] pservices =
PrintServiceLookup.lookupPrintServices(flavor, aset);
if (pservices.length > 0) {
DocPrintJob pj = pservices[0].createPrintJob();
// InputStreamDoc is an implementation of the Doc interface //
Doc doc = new InputStreamDoc("test.ps", flavor);
try {
pj.print(doc, aset);
} catch (PrintException e) {
}
}
That's why you have applets. But applets run in a security sandbox. However, if the right kind of privileges are given to the applet running in a webapp, it can open socket, write to files, write to serial port, etc.