Develop Reference

Opening external application from user input

I want to be able to open an application like internet, notepad, iTunes, and any other .exe file from use input.
Right now I got this;
(ext is the user input)
try
{
Process p = Runtime.getRuntime().exec(ext + ".exe");
}
catch(Exception e1){ }
This, however, only seems to be able to open notepad, is there any way I can make it so it can open any installed .exe file?
[NOTE]
I'm trying to do this from a java-window I created

For example this line runs Skype
Process p = Runtime.getRuntime().exec("C:/Program Files (x86)/Skype/Phone/skype.exe");

determine version of microsoft office with java

I wrote a program that creates a set of data that is outputted to an excel spreadsheet. I was originally using the jexcel library to write the data to the file, but I'd like to update the program so that it can check and see whether is should create a ".xls" or ".xlsx" file, then write to the appropriate document type. Apache POI seems to be the best option in terms of writing to a ".xlsx" file, but any ideas about determining the correct file type?
I could just have the user choose when naming the file, but that seems like extra work for the user and I'm assuming that there are users who don't know what file type they'd want.
Any ideas?
Also, I'm assuming the OS is windows and the user has some version of excel, in other cases I'll just choose a default file type.

One way is to call the Windows ASSOC and FTYPE commands, capture the output and parse it to determine the Office version installed.
C:\Users\me>assoc .xls
.xls=Excel.Sheet.8
C:\Users\me>ftype Excel.sheet.8
Excel.sheet.8="C:\Program Files (x86)\Microsoft Office\Office12\EXCEL.EXE" /e
Here a quick example :
import java.io.*;
public class ShowOfficeInstalled {
public static void main(String argv[]) {
try {
Process p = Runtime.getRuntime().exec
(new String [] { "cmd.exe", "/c", "assoc", ".xls"});
BufferedReader input =
new BufferedReader
(new InputStreamReader(p.getInputStream()));
String extensionType = input.readLine();
input.close();
// extract type
if (extensionType == null) {
System.out.println("no office installed ?");
System.exit(1);
}
String fileType[] = extensionType.split("=");
p = Runtime.getRuntime().exec
(new String [] { "cmd.exe", "/c", "ftype", fileType[1]});
input =
new BufferedReader
(new InputStreamReader(p.getInputStream()));
String fileAssociation = input.readLine();
// extract path
String officePath = fileAssociation.split("=")[1];
System.out.println(officePath);
}
catch (Exception err) {
err.printStackTrace();
}
}
}
You may want to add more error checking and the parsing to extract the Office version from the returned path is left as an exercise ;-)

You can search in the registry for the key:
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\App Paths
This will probably require some work, as evidenced by this question:
read/write to Windows Registry using Java

If you're willing to dive into the registry (eg with jregistrykey) a translated version of this PowerShell script should do what you want.

Take a look at OfficeVer.
You can implement it to your script or use it for code analysis. It's cross-platform much like Java, so compiling it and implementing it directly shouldn't be a big deal.
It works by extracting .docx and xlsx files and then reading the version, as well as reading directly from .doc and .xls files.
OfficeVer as well has extended their support to .pdf files (current version as of time of writing is 1.03.1)

java open csv file using excel

I am making a project for college and have made a program which creates csv files. I would like there to be a button which you can click which then opens the csv file with excel. Thanks

Knowing that MsOffice is installed on the system, you should be able to open a document with it from command line using the command
excel myDoc.csv
to execute such a command from java, you could use this snapshot:
File myCSVFile; //reference to your file here
String execString = "excel " + myCSVFile.getAbsolutePath();
Runtime run = Runtime.getRuntime();
try {
Process pp = run.exec(execString);
} catch(Exception e) {
e.printStackTrace();
}
This is somewhat rough and needs styling, of course, but generally it should work. Besides, to be more graceful you could also check Windows registry, using the java.util.prefs.Preferences class, to know if MsOffice is installed and, if yes, where. But, please, be aware, if you are reckoning for MsExcel (as I understood from your post), this will automatically cancel Java's multiplatform approach. Hopefully, this helps :)

If you are using Java 6 you can use the Desktop class. Read also Opening, Editing, and Printing a File

You can use JExcel API. It will be very easy for you.

For whatever reason, execString's provided did not work for me, but the one below worked:
String execString = "cmd /c start excel \"" + filePathString + "\"";
With the other exeString's I kept getting an exception saying that the runtime cannot find the file - start or excel.

How to open the notepad file in java?

I want to open Notepad in my Java program. Suppose that I have one button if I click this button the notepad will appear.
I already have a file name and a directory.
How can I implement this case?

Try
if (Desktop.isDesktopSupported()) {
Desktop.getDesktop().edit(file);
} else {
// I don't know, up to you to handle this
}
Make sure the file exists. Thanks to Andreas_D who pointed this out.

(assuming you want notepad to open "myfile.txt" :)
ProcessBuilder pb = new ProcessBuilder("Notepad.exe", "myfile.txt");
pb.start();

Assuming you wish to launch the windows program notepad.exe, you are looking for the exec function. You probably want to call something like:
Runtime runtime = Runtime.getRuntime();
Process process = runtime.exec("C:\\path\\to\\notepad.exe C:\\path\\to\\file.txt");
For example, on my machine notepad is located at C:\Windows\notepad.exe:
Runtime runtime = Runtime.getRuntime();
Process process = runtime.exec("C:\\Windows\\notepad.exe C:\\test.txt");
This will open notepad with the file test.txt open for editing.
Note you can also specify a third parameter to exec which is the working directory to execute from - therefore, you could launch a text file that is stored relative to the working directory of your program.

Using SWT, you can launch any
If you want to emulate double-clicking on a text in windows, it's not possible only with a plain JRE. You can use a native library like SWT and use the following code to open a file:
org.eclipse.swt.program.Program.launch("c:\path\to\file.txt")
If you don't want to use a third-party lib, you should know and you know where notepad.exe is (or it's visible in PATH):
runtime.exec("notepad.exe c:\path\to\file.txt");
Apache common-exec is a good library for handling external process execution.
UPDATE: A more complete answer to your question can be found here

In IDE (Eclipse) it compains about "C:\path\to\notepad.exe C:\path\to\file.txt" .
So i have used the following which works for me keeping me and my IDE happy :o)
Hopefully this will help others out there.
String fpath;
fPath =System.getProperty("java.io.tmpdir")+"filename1" +getDateTime()+".txt";
//SA - Below launches the generated file, via explorer then delete the file "fPath"
try {
Runtime runtime = Runtime.getRuntime();
Process process = runtime.exec("explorer " + fPath);
Thread.sleep(500); //lets give the OS some time to open the file before deleting
boolean success = (new File(fPath)).delete();
if (!success) {
System.out.println("failed to delete file :"+fPath);
// Deletion failed
}
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

String fileName = "C:\\Users\\Riyasam\\Documents\\NetBeansProjects\\Student Project\\src\\studentproject\\resources\\RealWorld.chm";
String[] commands = {"cmd", "/c", fileName};
try {
Runtime.getRuntime().exec(commands);
//Runtime.getRuntime().exec("C:\\Users\\Riyasam\\Documents\\NetBeansProjects\\SwingTest\\src\\Test\\RealWorld.chm");
} catch (Exception ex) {
ex.printStackTrace();
}

You could do this the best if you start notepad in command line with command: start notepad
String[] startNotePadWithoutAdminPermissions = new String[] {"CMD.EXE", "/C", "start" "notepad" };
Save array of string commands and give it like parametr in exec
Process runtimeProcess = Runtime.getRuntime().exec(startNotepadAdmin2);
runtimeProcess.waitFor();

How can I excute Notepad by Java code

I want to open Notepad program in MS Windows by Java code to open my text file.
Pls help me to do that.

You can use the java.awt.Desktop if using Java 1.6, .txt is registered to the notepad and Desktop is supported:
if (!Desktop.isDesktopSupported()) {
System.err.println("Desktop not supported");
// use alternative (Runtime.exec)
return;
}
Desktop desktop = Desktop.getDesktop();
if (!desktop.isSupported(Desktop.Action.EDIT)) {
System.err.println("EDIT not supported");
// use alternative (Runtime.exec)
return;
}
try {
desktop.edit(new File("test.txt"));
} catch (IOException ex) {
ex.printStackTrace();
}
this way you can open/edit files in a more OS independent way.

Runtime.getRuntime().exec("notepad c:/asd.txt");
where c:/asd.txt is the full path to your text file. If / doesn't work for you, use \\ instead.

If you have registered the .txt extension on your OS and your text file already exists then you can do even
Runtime.getRuntime().exec(new String[]{"cmd.exe","/c","text.txt"});
The advantage is it will take the program associated with .txt, what could be diferent from notepad.exe.

use the ProcessBuilder Class
Process p = new ProcessBuilder("notepad", "file.txt").start();