Proper Java path when using Ubuntu's Runtime.exec()

Question

How do I give the path for Ubuntu's runtime.exec? I am not getting output while executing the below program:

import java.io.IOException;

public class Modify {

    public static void main(String args[]) {
        Runtime rt = Runtime.getRuntime();
        try {
            rt.exec("java -jar home/srinathm/srinath/invalidxml/atlassian-xml-cleaner-0.1.jar home/srinathm/srinath/invalidxml/FAR4031_V_rdf.xml >home/srinathm/srinath/invalidxml/data-clean.xml");

        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

    }

}

With his code, data-clean.xml is not generated.

Any help would be appreciated.

Answer 1

My guess is that you don't have Java in your PATH. It is difficult to tell without knowing what the actual error message is.

Try using /usr/bin/java and see if that helps, as shown below:

rt.exec("/usr/bin/java -jar home/srinathm/srinath/invalidxml/atlassian-xml-cleaner-0.1.jar home/srinathm/srinath/invalidxml/FAR4031_V_rdf.xml >home/srinathm/srinath/invalidxml/data-clean.xml");

Answer 2

public static void main(String args[]) {

    try {
        ProcessBuilder builder = new ProcessBuilder(new String[]{"java","-jar","/atlassian-xml-cleaner-0.1.jar","/home/srinathm/invalid xml/FAR4031_V_rdf.xml"});
            builder.redirectErrorStream(true);
            Process p = builder.start();

            BufferedInputStream in = null;
            FileOutputStream out = null;

            try {
               in = new BufferedInputStream(p.getInputStream());
               out = new FileOutputStream("/home/srinathm/srinath/invalidxml/output.xml");

               int c;
               while ((c = in.read()) != -1) {
                  out.write(c);
               }
            }finally {
               if (in != null) {
                  in.close();
               }
               if (out != null) {
                  out.close();
               }
            }


    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

}

I am getting by using streams

Answer 3

Java's external process execution tools are not a shell, and they don't understand redirection operators like > . Instead of Runtime.exec I would recommend you switch to ProcessBuilder , which can do the redirect to a file directly:

ProcessBuilder pb = new ProcessBuilder("java", "-jar",
  "home/srinathm/srinath/invalidxml/atlassian-xml-cleaner-0.1.jar",
  "home/srinathm/srinath/invalidxml/FAR4031_V_rdf.xml");
pb.redirectOutput(new File("home/srinathm/srinath/invalidxml/data-clean.xml"));
pb.redirectError(ProcessBuilder.Redirect.INHERIT); // send process stderr to java's stderr
Process p = pb.start();
p.waitFor();