How to use Java Runtime.exec() with Windows REG utility to Read/Update/Delete entries in HKEY_LOCAL_MACHINE\...\CurrentVersion\Run?

Question

I want to use Runtime.exec() to update the registry for HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run using the Windows REG command utility.

Need to be able to add/remove/read an entry from the "Run" key to allow my Swing application to run at startup and check if it is configured to run at startup so I can mark the option as checked or unchecked in the GUI. I had this working with JNI but the library was 32bit only so it doesn't work on 64bit. I'm thinking this will be a better approach. Don't even need to include a library this way and I don't think REG is going away or changing.

Has anyone done this before or know how to do this?

Thanks!

Answer 1

This approach might not work as expected. See http://stackoverflow.com/questions/2416796/in-x64-windows-is-there-a-way-to-run-a-runtime-exec-process-avoiding-registry

Answer 2

I added a couple new methods (addValue/deleteValue) to the example found here: http://stackoverflow.com/questions/62289/read-write-to-windows-registry-using-java/1982033#1982033

/**
 * @author Oleg Ryaboy, based on work by Miguel Enriquez
 */
public class WindowsReqistry
{

    /**
     * 
     * @param location
     *          path in the registry
     * @param key
     *          registry key
     * @return registry value or null if not found
     */
    public static final String readRegistry(String location, String key)
    {
        try
        {
            // Run reg query, then read output with StreamReader (internal class)
            Process process = Runtime.getRuntime().exec("reg query \"" + location + "\" /v \"" + key + "\"");

            StreamReader reader = new StreamReader(process.getInputStream());
            reader.start();
            process.waitFor();
            reader.join();
            String output = reader.getResult();

            // Output has the following format:
            // \n<Version information>\n\n<key>\t<registry type>\t<value>
            if (!output.contains("\t"))
            {
                return null;
            }

            // Parse out the value
            String[] parsed = output.split("\t");
            if(parsed.length > 0)
            {
                String result = parsed[parsed.length - 1].trim();
                result = result.substring(1, result.length() - 1);
                return result;
            }
        }
        catch (Exception e)
        {
        }
        return null;
    }

    static class StreamReader extends Thread
    {
        private InputStream is;
        private StringWriter sw = new StringWriter();;

        public StreamReader(InputStream is)
        {
            this.is = is;
        }

        public void run()
        {
            try
            {
                int c;
                while ((c = is.read()) != -1)
                    sw.write(c);
            }
            catch (IOException e)
            {
            }
            finally
            {
                try
                {
                    is.close();
                }
                catch (IOException e)
                {
                    e.printStackTrace();
                }
            }
        }

        public String getResult()
        {
            return sw.toString();
        }
    }

    public static boolean deleteValue(String key, String valueName)
    {
        try
        {
            // Run reg query, then read output with StreamReader (internal class)
            Process process = Runtime.getRuntime().exec("reg delete \"" + key + "\" /v \"" + valueName + "\" /f");

            StreamReader reader = new StreamReader(process.getInputStream());
            reader.start();
            process.waitFor();
            reader.join();
            String output = reader.getResult();

            // Output has the following format:
            // \n<Version information>\n\n<key>\t<registry type>\t<value>
            return output.contains("The operation completed successfully");
        }
        catch (Exception e)
        {
        }
        return false;
    }

    public static boolean addValue(String key, String valName, String val)
    {
        try
        {
            // Run reg query, then read output with StreamReader (internal class)
            Process process = Runtime.getRuntime().exec(
                    "reg add \"" + key + "\" /v \"" + valName + "\" /d \"\\\"" + val + "\\\"\" /f");

            StreamReader reader = new StreamReader(process.getInputStream());
            reader.start();
            process.waitFor();
            reader.join();
            String output = reader.getResult();

            // Output has the following format:
            // \n<Version information>\n\n<key>\t<registry type>\t<value>
            return output.contains("The operation completed successfully");
        }
        catch (Exception e)
        {
        }
        return false;
    }

}