I am using imagemagick in my application. Our development machine is Windows and live server is linux. Now, in online it is working fine online. But not in development machine. I downloaded and installed Imagemagick latest release for Windows and when i try the below command in DOS-prompt, it is working fine.
convert -sample 100x100 D:\test.jpg D:\test-cropped.jpg
But when i run the same as command-line in Java program, it is not working and not giving any error too.
My code is :
Runtime.getRuntime().exec("convert -sample 250x150 "+pathName+digest+".jpg "+pathName+digest+"_thumb.jpg");
Any help is appareciated.
convert.exe is available in ImageMagick installation directory. So you need to add ImageMagick installation directory in environment variable path.
Another option is to provide complete path of convert.exe as :
Runtime.getRuntime().exec("C:\\program files\\ImageMagick\\convert -sample 250x150 "+pathName+digest+".jpg "+pathName+digest+"_thumb.jpg");
try
execute convert using the absolute path
quote your parameter input file and output file, in case they contain space
I suspect the problem is spaces in pathnames, but the solution is NOT to use escapes or quotes. The exec(String) method splits the string into "arguments" in a completely naive fashion by looking for white-space. It pays no attention whatsoever to quoting, etcetera. Instead, you will end up with command names and arguments that have quote characters, etcetera embedded in them.
The solution is to use the overload of exec that takes a String[], and do the argument splitting yourself; e.g.
Runtime.getRuntime().exec(new String[]{
"convert", // or "D:\\Program Files (x86)\\ImageMagick-6.8.0-Q16\\convert\\"
"-sample",
"250x150",
pathName + digest + ".jpg",
pathName + digest + "_thumb.jpg"
});
The other thing you could do is to capture and print any output that is written to the processes stdout and stderr.
In my case, the problem I was facing that from java compare command was working fine using Runtime.getRuntime().exec(), but when using convert, it was not working and returning me exit value as 4.
Compare execution returns exit value 0, telling that it is successfully executed.
I have system path updated with the ImageMagic's installation directory, still it was not picking 'convert' exe file. So, I started giving complete path of the convert.exe file instead of only writing only convert
e.g:
Runtime.getRuntime().exec("C:/Program files/ImageMagic......../convert.exe myImage1 -draw .... myImage2") and it worked fine this time.
Some how system was not able to pick the convert application and giving full path sorted it out. May be this solution would help someone facing same type of issue.
Related
I am a high school student working on a project that will convert the video from a YouTube link into an MP3 and download it. However, the way that the video form YouTube is downloaded and converted is through the Mac OS terminal by using YouTube-dl.
This is what I put into the terminal:
youtube-dl -f bestvideo+bestaudio \"ytsearch:{https://www.youtube.com/watch?v=5X-Mrc2l1d0}\"
This works in terminal, but when I try to use:
Runtime.getRuntime().exec("cd /Users/poppa/Desktop/IA Vids");
and there's an error saying "No such file or directory"
Another Problem that I am having is running the code that is inputted into the Terminal from Java. I'm using IntelliJ IDEA if that helps. Thank You!
You have a space in the directory path. Try putting double quotes around like this:
Runtime.getRuntime().exec("cd \"/Users/zeidakel/Desktop/IA Vids\"");
Also note that executing cd command from JVM may have no effect on current user dir when (for example) creating files with new File("path")
If cd means change directory (and isn't the name of an executable), then it almost certainly won't take effect, even if it is executed correctly. The process spawned by exec() will have a working directory, and it can be changed -- but that change will only affect the spawned process.
In addition, having spaces in arguments to exec() is inherently problematic. exec() is not a shell, and you won't be able to protect the string from being split at the spaces by using shell mechanisms like quotes. Instead, you need to split the command into arguments yourself, knowing where the splits should be, and then use the form of exec() that takes a String[] as input. That is, split the arguments into an array of strings yourself, rather than relying on exec() to do it for you (wrongly).
Runtime.exec() is fraught with difficulties, and needs very careful handling. I've written extensively about this subject here:
http://kevinboone.me/exec.html
In my Java program I'm creating a Least Squares Approximation and exporting the coefficients, i.e. c1x+c2x^2+c3x^3..., to a text file that my Python script will read in and plot. However, I cannot even get a basic Hello World python file to run from my Java program. I've scoured the internet for answers and I've used all the tricks in the book. This is what I did: methodsOneThroughTwo methodsThreeThroughFour , and here is the output: exceptions .
I have the same python file, test.py, placed in two different locations, the first one being the directory of the java program (C:\Users\BScot\OneDrive\Desktop\Numerical Analysis\Lab2\test.py) and the second being in the directory of a python project, (C:\Users\BScot\OneDrive\Desktop\Numerical Analysis\Test\test.py), just to check if that would make a difference.
Some of the exceptions indicate that the file is found but it cannot run because it is not an executable; but when I add the python start command to the front of the file path it reads that it cannot find the file "python".
Any help would be much appreciated.
You have space character in python script path. Try to quote it with \" \"
Also you should take a look at ProcessBuilder: https://docs.oracle.com/javase/7/docs/api/java/lang/ProcessBuilder.html
String[] cmd = {
"gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/screen -dNOPAUSE -dQUIET -dBATCH -sOutputFile= C:\\Users\\342008\\Desktop\\t\\Pa_10_12.pdf C:\\Users\\342008\\Desktop\\t\\P1_10_12.pdf"
};
try {
Runtime.getRuntime().exec(cmd);
} catch (IOException e) {}
am trying to use ghost script to reduce the PDF file size with the help of command line argumenet, am getting IOexception for the above input string object cmd, could some one please help run this command to use ghostscript?
Firstly, while it is possible that running a PDF file through the pdfwrite device will make the file smaller, this is not the purpose of the device, and there are circumstances under which it will produce a bigger file.
If you really want to do this, then don't use the -dPDFSETTINGS switch. Instead set each parameter individually, take the time to read the documentation and see what they do so that you can make an informed choice.
You haven't said what operating system you are using, nor which version of Ghostscript, but I can see several possible problems:
1) The Ghostscript executable is not called 'gs' on all operating systems, possibly you are using the wrong name. The syntax of the parameters leads me to believe this is a Windows system, in which case the executable is called gswin32 (for the windowed version) or gswin32c (for the command line version).
2) You haven't specified a path to the executable. This will only work if the executable can be found on the OS' search path (usually the %PATH% environment variable)
Your command line apparently includes "-sOutputFile= C:\Users\342008\Desktop\t\Pa_10_12.pdf" You must NOT leave extraneous spaces in parameters. What you have written there will cause GS to assume an output file with an empty name, and then treat the filename as an input file for processing.
I would suggest that before you try this in Java you try running the command from the command line of your Operating System. If that doesn't work then it isn't going to work from Java either......
I'm trying to write a script to rename a computer (among other things) but just can't seem to figure it out. I don't really care what method I use to change the computer as long as i can change it. I found out how to read the computer name by doing
String computername = InetAddress.getLocalHost().getHostName();
However, that doesn't seem to offer any help in setting the computer name. Is there a way to set the Computer Name directly in the java console?
If not, or if anyone has better experience in this area, I also wrote a script using powershell 2.0 that renames the computer. I'm trying to figure out how to run that using
Runtime rt = Runtime.getRuntime();
Process proc = rt.exec("file location");
I followed the guide here but when trying to run a test .bat file that should just open the command line I just get this output in the java console:
C:\Users\Stephen\Desktop\opencmd.bat is found
OUTPUT>
OUTPUT>C:\Users\Stephen\workspace\UNM computer rename>cmd.exe
OUTPUT>Microsoft Windows [Version 6.1.7601]
OUTPUT>Copyright (c) 2009 Microsoft Corporation. All rights reserved.
OUTPUT>
It looks like it's just spitting back the command line output into the java console, instead of just running the command and opening the cmd line.
I would really appreciate input as I'm in a crunch for time here, thanks!
First, JDK really does not provide pure java API that allows changing computer name. So you have to run script.
Second, if you want to run script using Runtime you have to provide correct command line. So first try to run your script manually. I believe it accepts a least one parameter (the new computer name). So run it from command prompt and see it is working. Then put it to the working directory of your java program and copy/paste the command line into the java code and see that it is working now. if you want you can read STDOUT of your script and/or get its return code. If you do not care about its output just call process.waitFor() and then get the return code.
Be careful with arguments. Windows computer name may contain unicode characters and spaces. If it contains spaces surround it with quotes. Concerning unicode just try. I hope it will not cause problems to you.
You can also use ProcessBuilder class that allows better and more portable arguments passing.
Good luck.
It looks like opencmd.bat is being executed, so assuming your PowerShell script works, is it possible you don't have administrative privileges?
You can also do it elegantly using JNA, I think this would be the target. But if you are rushed for time, don't bother.
I am trying to run a perl command with Java runtime exec in linux/ubuntu/gnome. The command generates an pdf file, but it saves it in my home folder. Is there any way that the exec method can set an output path for the commands executed? Thanks in advance.
The exec method just runs the command on the operating system, so you'll want to change the command you're running with exec more than anything in "Java" per se.
There are a few possibilities:
Change the working directory of your java program. The .pdf is being saved in your working directory because this is where the program is being run.
Unfortunately it's not simple to change this value after the program has been launched. It is, however, trivial to change before the program starts; just change the working directory before starting the program.
Move the file to it's desired location after it's been created in your home directory.
Change the command so that it includes the target location. Your perl script may have an option that will enable you to save it's output to a certain location (usually -o or --output). Using this your program would change from:
Runtime.exec("perl someprogram");
to something like:
Runtime.exec("perl someprogram -o /path/to/some.file")
You might be able to use "output redirection", if there is no option to do this.
Try something like what's below as your argument:
Runtime.exec("perl someprogram > /path/to/some.file")
Unfortunately, without knowing more details of your situation I can't provide more concrete advice.
While each approach has benefits and drawbacks, it's probably best to just implement the one that you understand best; if you can't get one to work, try another.
A good, free online resource for learning is Introduction to Linux: A Hands On Guide.
Section 2.2 has details on cd which you can use for 1..
Section 3.3, section 3 teaches about the mv command, which will be useful in 2..
Section 5.1 is about I/O redirection. Knowing about "output redirection" and the > operator, are important for 4..
For 3., you'll have to consult the documentation of the perl program you're using.
You could modify the Perl script to accept an absolute path for the output.
You can trying setting the working directory using exec(java.lang.String[], java.lang.String[], java.io.File) where File is the directory the command is executed from.
If all else fails, you'll can always copy the generated file from the Home directory to your final location.