java.io.IOException: Cannot run program "...": java.io.IOException: error=2, No such file or directory

Question

I need to execute an external program from Java (to convert a fodt file to pdf using libreoffice, it so happens) I know the precise command-line I need for the program:

/usr/bin/libreoffice --headless --convert-to pdf:'writer_pdf_Export' --outdir /home/develop/tomcat/mf/ROOT/private/docs/0/ /home/develop/tomcat/mf/ROOT/private/docs/0/35_invoice.fodt

and that works perfectly from the command line. But it does not work in Java using a ProcessBuilder:

java.io.IOException: Cannot run program "/usr/bin/libreoffice --headless --convert-to pdf:'writer_pdf_Export' --outdir /home/develop/tomcat/mf/ROOT/private/docs/0 /home/develop/tomcat/mf/ROOT/private/docs/0/35_invoice.fodt": java.io.IOException: error=2, No such file or directory

I tried some different approaches without success. Here is a sample of the last test

        List<String> command = new ArrayList<String>();
        command.add("/usr/bin/libreoffice");
        command.add("--headless");
        command.add("--convert-to pdf:'writer_pdf_Export' --outdir " + getDestinationDirectory(order) + " " + getInvoiceFilename() + ".fodt");
  
        ProcessBuilder builder = new ProcessBuilder(command);

        Process process = null;
        try {
            process = builder.start();
        } catch (IOException ex) {
            Logger.getLogger(Documents.class.getName()).log(Level.SEVERE, null, ex);
        }
        InputStream is = process.getInputStream();
        InputStreamReader isr = new InputStreamReader(is);
        BufferedReader br = new BufferedReader(isr);
        String line;
        try {
            while ((line = br.readLine()) != null) {
                System.out.println(line);
            }
        } catch (IOException ex) {
            Logger.getLogger(Documents.class.getName()).log(Level.SEVERE, null, ex);
        }
        System.out.println("Program terminated!");

Answer 1

The ProcessBuilder constructors require each argument of the external program to be separate (in the form of an array or List of Strings). The first exception message you got,

Cannot run program "/usr/bin/libreoffice --headless --convert-to pdf:'writer_pdf_Export' --outdir /home/develop/tomcat/mf/ROOT/private/docs/0 /home/develop/tomcat/mf/ROOT/private/docs/0/35_invoice.fodt"

is not complaining that it can find a program named /usr/bin/libreoffice. It is complaining that it can not find a program with the very long and peculiar name "/usr/bin/libreoffice --headless --convert-to pdf:'writer_pdf_Export' --outdir /home/develop/tomcat/mf/ROOT/private/docs/0 /home/develop/tomcat/mf/ROOT/private/docs/0/35_invoice.fodt", because you concatenated the arguments into one String.

Instead of

command.add("--convert-to pdf:'writer_pdf_Export' --outdir " + getDestinationDirectory(order) + " " + getInvoiceFilename() + ".fodt")

and such like, split each of the arguments into its own call to List.add

command.add("--convert-to");
command.add("pdf:writer_pdf_Export");

command.add("--outdir");
command.add(getDestinationDirectory(order).toString());

command.add(getInvoiceFilename() + ".fodt");

Note that there are no apostrophes around "writer_pdf_Export" since those are shell meta-characters and are not required when you're constructing an array to pass to exec without an intermediating shell.

Answer 2

Try this (keep it simple) ...

Process p = Runtime.getRuntime().exec("/usr/bin/libreoffice --headless --convert-to pdf:'writer_pdf_Export' --outdir "+ getDestinationDirectory(order)+" "+getInvoiceFilename()+".fodt");

Fully ...

    Process process = null;
    try {
            process = Runtime.getRuntime().exec("/usr/bin/libreoffice --headless --convert-to pdf:'writer_pdf_Export' --outdir "+ getDestinationDirectory(order)+" "+getInvoiceFilename()+".fodt");
    } catch (IOException ex) {
        Logger.getLogger(Documents.class.getName()).log(Level.SEVERE, null, ex);
    }
    BufferedReader br = new BufferedReader(new InputStreamReader(process.getInputStream()));
    String line;
    try {
        while ((line = br.readLine()) != null) {
            System.out.println(line);
        }
    } catch (IOException ex) {
        Logger.getLogger(Documents.class.getName()).log(Level.SEVERE, null, ex);
    }
    br.close();
    System.out.println("Program terminated!");