Java works stand alone does not when called from PL/SQL

Question

I have this piece of code, which works as a standalone program: It takes in the en_var and returns a path.
But it wont work when called from a store procedure the line of code p = rt.exec("echo "+envar); returns a path as a standalone program returns null when called from a Oracle store procedure.
Thanks for any help just going around and round in circles.
import java.util.*;
class translate
public static String translatePath(String envar)
Runtime rt = Runtime.getRuntime();
int bufSize = 4096;
byte buffer[] = new byte[bufSize];
String path = null;
Process p = null;
String os = null;
String name = null;
String home = null;
String dir = null;
SecurityManager sm = null;
int len = 0;
try
System.out.println("Calling echo "+envar);
os = System.getProperty("os.name");
name = System.getProperty("user.name");
home = System.getProperty("user.home");
dir = System.getProperty("user.dir");
sm = System.getSecurityManager();
p = rt.exec("echo "+envar);
BufferedInputStream bis = new BufferedInputStream(p.getInputStream());
while ((len = bis.read(buffer, 0, bufSize)) != -1)
System.out.write(buffer, 0, len);
path = new String(buffer);
//p.waitFor();
bis.close();
return path;
catch(Exception e)
System.out.println("Exception "+e);
return "ProcessProblem";
//path = "/rims/live/log";

Answer 1

Still cant get it to work, it doesnt fall over anymore, but when I input $PATH, it will output $PATH instead of the path for $PATH i.e /rims/live: What does your program output please:
Here is my code:
import java.io.*;
import java.util.*;
class translate
     public static String translatePath(String envar)
          Runtime rt = Runtime.getRuntime();
          Process p = null;
          String echoOutput = null;
          int len = 0;
          try
               System.out.println("Calling echo "+envar);
               p = rt.exec(new String[]{"/bin/echo",envar});
               InputStreamReader isr = new InputStreamReader(p.getInputStream());
               BufferedReader br = new BufferedReader(isr);
               echoOutput = br.readLine();
               br.close();
               isr.close();
               return echoOutput;
          catch(Exception e)
               System.out.println("Exception "+e);
               return "ProcessProblem";
          //path = "/rims/live/log";
Thanks for all your help so far.
Tony