Develop Reference

Using XLLoop for java

XLLoop is opensource framework to java. For example we can use function from java in excel. Below is very simple example of usage:
package org.boris.xlloop.util;
import org.boris.xlloop.FunctionServer;
import org.boris.xlloop.handler.*;
import org.boris.xlloop.reflect.*;
public class ServerExample
{
public static void main(String[] args) throws Exception {
// Create function server on the default port
FunctionServer fs = new FunctionServer();
// Create a reflection function handler and add the Math methods
ReflectFunctionHandler rfh = new ReflectFunctionHandler();
rfh.addMethods("Math.", Math.class);
rfh.addMethods("Math.", Maths.class);
rfh.addMethods("CSV.", CSV.class);
rfh.addMethods("Reflect.", Reflect.class);
// Create a function information handler to register our functions
FunctionInformationHandler firh = new FunctionInformationHandler();
firh.add(rfh.getFunctions());
// Set the handlers
CompositeFunctionHandler cfh = new CompositeFunctionHandler();
cfh.add(rfh);
cfh.add(firh);
fs.setFunctionHandler(new DebugFunctionHandler(cfh));
// Run the engine
System.out.println("Listening on port " + fs.getPort() + "...");
fs.run();
}
}
I understand it and generally programm is working. But if I go to excel, it isn't working.
I try:
=FS("Math.random")
=Math.random()
But I got #NAME? twice
So I suppose that I should make something yet. Could you tell me step by step how configure excel and java to do this? What should I do with xlloop-0.3.2 (Microsoft Excel XLL Add-In) file ?

I tried running the code and I got the following output.
All I had to do was to launch Excel and add the XLLoop addin.
. Press Alt+G or click on the Go button beside Manage Excel Add-ins.
. Click on Browse and provide the path to the xlloop-0.3.2.xll file. If you had downloaded xlloop-0.3.2.zip,extract it and you will find it inside /xlloop/bin
Hope that helps.
Edit:
Launch Excel.
Start the server(run the Main class) and test the formulas.
I tested the following 2(typed them on the Excel formula bar and hit/press Enter) and it worked fine. :)
=FS("Math.sin", 3.14)
=FS("Math.random")

For anyone running into the same problem:
You have to add the correct Addin Version to your excel installation.
If you are getting the error message: "The file format and extension [...] don't match.", it means that you are using a 64bit excel and the 32bit XLLoop addin.
You have to either install a 32bit Excel, or you have to get the 64bit version of the XLLoop Plugin.
We ran into the same problem, and created a 64bit version of the addin: https://github.com/PATRONAS/xlloop

Webpage Java Applet - Open On Screen Keyboard

I'm trying to open the On Screen Keyboard from within a web application on a touch screen interface. I am using Opera as the browser for the built in "Kiosk" features, but it does not support VBScript- an easy way of openning a .exe file from a webpage.
I know Java can be ran from within a web page and it can also be used to open another application, such as the OSK!
Below is my working Java code:
package runtimeexec;
import java.io.IOException;
public class RuntimeExec {
public static void main(String[] args) {
try {
Runtime runTime = Runtime.getRuntime();
Process process = runTime.exec("cmd /c osk");
} catch (IOException e) {
e.printStackTrace();
}
}
}
Now I want to embed this into a webpage, so that it can open the osk. My .class file is at http://theyconfuse.me/java/runtimeexec/RuntimeExec.class and my current attempt to embed this code is at http://theyconfuse.me/java/ with the following embed code:
<applet codebase="http://theyconfuse.me/java/runtimeexec" code="RuntimeExec.class" width="200" height="200"></applet>
How ever, when I load the page, I get the following:
NoClassDefFoundError
RuntimeExec (wrong name: runtimeexec/RuntimeExec)
Can anyone help me with what am I missing here? Thanks

code="RuntimeExec.class"
Should be with package structure, separated by dots, but without the .class extension.
code="runtimeexec.RuntimeExec"

Trouble with ProcessBuilder

Following code opens status very fine in notepad:
import java.util.*;
class test
{
public static void main(String args[])
{
try{
ProcessBuilder pb=new ProcessBuilder("notepad","F:/status");
pb.start();
}catch(Exception e)
{
System.out.println(e);
}
}
}
Following code does'not play the song:
import java.util.*;
class test
{
public static void main(String args[])
{
try{
ProcessBuilder pb=new ProcessBuilder("C:/Program Files (x86)/VideoLAN/VLC/vlc","D:/02 Tu Jaane Na");
pb.start();
}catch(Exception e)
{
System.out.println(e);
}
}
}

I think that the problem is that you're ignoring the fact that the files you're trying to open have filename extensions.
Windows Explorer doesn't display file extensions by default - that is probably why you are not aware of their existence.
The reason why notepad worked in your first example is that notepad automatically adds .txt extension to its filename parameter in case you didn't provide one yourself. So in reality the file that is being open is not status but status.txt.
VLC doesn't have this "advanced" functionality because there's no specific filename extension it is designed to work with.
So you will need to look up the dir command output and add the full file name as a parameter.
If that was the real issue - you might want to modify your Windows Explorer settings for it to display file extensions:
or, which is better, switch to a more programmer-friendly OS :)

For 1.6+ code, use Desktop.open(File) instead.
Of course, the sensible thing to do immediately before calling that is to check File.exists().
OTOH, Desktop.open(File) throws a slew of handy exceptions, including:
NullPointerException - if file is null
IllegalArgumentException - if the specified file doesn't exist
UnsupportedOperationException - if the current platform does not support the Desktop.Action.OPEN action
IOException - if the specified file has no associated application or the associated application fails to be launched
Properly handled, the exception would indicate the immediate problem.
As an aside, the Desktop class is designed to be cross-platform, and will handle any file type for which an association is defined. In that sense it is a lot more useful for something like this, than trying to use a Process.

java.awt.Desktop.open doesn’t work with PDF files?

It looks like I cannot use Desktop.open() on PDF files regardless of location. Here's a small test program:
package com.example.bugs;
import java.awt.Desktop;
import java.io.File;
import java.io.IOException;
public class DesktopOpenBug {
static public void main(String[] args)
{
try {
Desktop desktop = null;
// Before more Desktop API is used, first check
// whether the API is supported by this particular
// virtual machine (VM) on this particular host.
if (Desktop.isDesktopSupported()) {
desktop = Desktop.getDesktop();
for (String path : args)
{
File file = new File(path);
System.out.println("Opening "+file);
desktop.open(file);
}
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
If I run DesktopOpenBug with arguments c:\tmp\zz1.txt c:\tmp\zz.xml c:\tmp\ss.pdf (3 files I happen to have lying around) I get this result: (the .txt and .xml files open up fine)
Opening c:\tmp\zz1.txt
Opening c:\tmp\zz.xml
Opening c:\tmp\ss.pdf
java.io.IOException: Failed to open file:/c:/tmp/ss.pdf. Error message:
The parameter is incorrect.
at sun.awt.windows.WDesktopPeer.ShellExecute(Unknown Source)
at sun.awt.windows.WDesktopPeer.open(Unknown Source)
at java.awt.Desktop.open(Unknown Source)
at com.example.bugs.DesktopOpenBug.main(DesktopOpenBug.java:21)
What the heck is going on? I'm running WinXP, I can type "c:\tmp\ss.pdf" at the command prompt and it opens up just fine.
edit: if this is an example of Sun Java bug #6764271 please help by voting for it. What a pain. >:(

I never knew about this Desktop command, untill recently through this post:
would Java's Runtime.getRuntime().exec() run on windows 7?
Previously i have been using:
Runtime.getRuntime().exec("rundll32 SHELL32.DLL,ShellExec_RunDLL "+ myfile);
And it has always worked for me. If your method does not work, may be you can think about try this command.

If you switch the order of your arugments does that cause one of the other files to get that same error. I wonder if you need to trim the end of the path before calling the File constructor.
umm...yeah ignore that... check the documentation of Desktop.open. open throws an IO exception "if the specified file has no associated application or the associated application fails to be launched " ... also from the top of the page... "The mechanism of registereing, accessing, and launching the associated application is platform-dependent. "
code for the Desktop class: http://fuseyism.com/classpath/doc/java/awt/Desktop-source.html
The open method calls DesktopPeer.open.
DesktopPeer source: http://www.jdocs.com/javase/7.b12/java/awt/peer/DesktopPeer.html
DesktopPeer is implementation specific.
Here is source for a Windows-specific implementation:
http://www.java2s.com/Open-Source/Java-Document/6.0-JDK-Platform/windows/sun/awt/windows/WDesktopPeer.java.htm
open->ShellExecute->(Native)ShellExecute
Native ShellExecute is a wrapper for Win32 ShellExecute. Here is info on the function.
http://msdn.microsoft.com/en-us/library/bb762153(VS.85).aspx
My suggestion for a work around would be to write your own implmentation of the ShellExecute function. Here is source from someone who did it. http://www.heimetli.ch/shellexec.html

How to open user system preferred editor for given file?

I'm trying to figure out how to open the system preferred editor for a given file.
Say, we have a file manager, written in Java. User goes to folder and sees the list of files. And, for example, there is a file Icon.jpg. User double clicks on the filename and file opens in system's preferred editor (i.e. Gimp). The main issue is - how to do that?
We can do Runtime.getRuntime().exec("something file"), but this way you should know which program is preferred in user environment. But how?
We also are able to do Desktop.getDesktop().edit(File file), but this way we cannot track process and aren't able to know then this child process is closed. Other issue - function doesn't work on linux (at least on Ubuntu 8.10). There is also Desktop.getDesktop().open(File file), but it forces to open file viewer, instead of system viewer for that file type.
I am searching for a solution all week, but didn't got any suitable and generic one. Do you know the other approaches to this question? For my project it would be enough if it would work on Windows+Linux+Mac.
Thank you for your answers and advices.
Edit on 2009-02-08 23:04
Other suggestion: can I force "application selection" window in Windows and in Linux, as in Mac with "open file"? For example, then you trying to open file, you are being asked to choose application from list of system preferred ones? (something like "Open with..." in Windows explorer). Do you know?

Seems that if you can't use java.awt.Desktop you have to distinguish between the OSes:
Windows:
RUNDLL32.EXE SHELL32.DLL,OpenAs_RunDLL <file.ext>
Linux:
edit <file.ext>
Mac:
open <file.ext>
HTH. Obviously, that is not very portable...

Check out the java.awt.Desktop object. In your case, you want to invoke edit()
If you want to ensure that a given platform supports this call, then you can do something like the following (I have not tested this code):
public boolean editFile(final File file) {
if (!Desktop.isDesktopSupported()) {
return false;
}
Desktop desktop = Desktop.getDesktop();
if (!desktop.isSupported(Desktop.Action.EDIT)) {
return false;
}
try {
desktop.edit(file);
} catch (IOException e) {
// Log an error
return false;
}
return true;
}

This isn't cross-platform, but on Mac OS X you can do
Runtime.getRuntime().exec("open filename");
The open(1) executable uses LaunchServices to pick the right program to execute, and then uses that to open the file named filename.

This will work in windows
Runtime.getRuntime().exec( "CMD /C START filename.ext " );

For JavaFX applications, we can use HostServices. This question covers how to use HostServices. This should work on Ubuntu (tested)/Windows (not tested) and Mac (not tested).
import java.io.File;
import java.io.IOException;
public class App extends Application {
}
File file = new File("/your/file/path");
HostServices hostServices = getHostServices();
hostServices.showDocument(file.getAbsolutePath());
getHostServices() is a method of JavaFX Application class.