Re: Runtime.exec(cmd) hangs up

"Vic" <vikrantp@gmail.com> wrote in message
news:1180131634.579210.23120@g37g2000prf.googlegroups.com...
| On May 25, 1:21 pm, "Matt Humphrey" <m...@ivizNOSPAM.com> wrote:
| > "Vic" <vikra...@gmail.com> wrote in message
| >
| > news:1180122190.487170.204980@a35g2000prd.googlegroups.com...
| > | Alright so here is my new code now, I implemented it the way you said
| > | (with some online help)
| > | class StreamGobbler extends Thread {
| > | InputStream is;
| > | String type;
| > |
| > | StreamGobbler(InputStream is, String type){
| > | this.is = is;
| > | this.type = type;
| > | }
| > |
| > | public void run(){
| > | try{
| > | InputStreamReader isr = new InputStreamReader(is);
| > | BufferedReader br = new BufferedReader(isr);
| > | String line = null;
| > | while((line = br.readLine()) != null){
| > | System.out.println(type+">"+line);
| > | }
| > | }
| > | catch(IOException ioe){
| > | ioe.printStackTrace();
| > | }
| > | }
| > | }
| > |
| > | class CommandExecuter {
| > | public static String stdout = null;
| > | public static String stderr = null;
| > | private String line;
| > |
| > | public CommandExecuter (String cmd) throws java.io.IOException{
| > | System.out.println("CommandExecuter: EXECUTING COMMAND: "+cmd);
| > | Process proc = Runtime.getRuntime().exec(cmd);
| > |
| > | StreamGobbler errorGobbler = new
| > | StreamGobbler(proc.getErrorStream(),"ERROR");
| > | StreamGobbler outputGobbler = new
| > | StreamGobbler(proc.getInputStream(),"OUTPUT");
| > |
| > | errorGobbler.start();
| > | outputGobbler.start();
| > |
| > | try{
| > | //VicP - temporary code to check the process status
| > | int val = proc.waitFor();
| > | //proc.wait(120000);
| > | }
| > | catch (Throwable t){
| > | t.printStackTrace();
| > | }
| > | }
| > | }
| > | But now the question is how do I set the value of stdout and stderr in
| > | CommandExecuter(As we are doing the stuff in thwo different threads
| > | now)? I need these values as they are checked in the calling function
| > | (which calls the Command executer constructor). Could you please
| > | suggest me some changes to get this?
| >
| > Your earlier example showed that you wanted to concatenate all the
output
| > into a single string. If that's what you want to do, add a StringBuffer
| > instance variable to the StreamGobbler and have the read loop append
each
| > line as you get it--rather than print it out. Modify the
CommandExecuter to
| > assign its stdout / stderr instance variables with the stream gobbler
| > contents when the process has completed. After the executer completes,
just
| > retrieve the values via get methods.
| >
| > If you want to actually process the strings as they arrive, that's a bit
| > more complicated.
| >
| > Matt Humphrey m...@ivizNOSPAM.comhttp://www.iviz.com/
|
| I talked to my manager and she allowed me to make stdout and stderr as
| "pulic static" (global) so I could directly access those in
| StreamGobbler as I am producing the output in those two thrads.
| Thank you so much for your help. have a great long weekend

That's the kind of problem I've seen trip up others and there's no reason to
use a static variable in this case because it's equally easy and much safer
to make it an instance variable. Good luck with your program.

Matt Humphrey matth@ivizNOSPAM.com http://www.iviz.com/