Re: Runtime.exec(cmd) hangs up

"Vic" <vikrantp@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 matth@ivizNOSPAM.com http://www.iviz.com/