multithreading - JAVA - External exe locking when called from launcher -

i have been trying use custom output stream display output executable on jtext area.

the executable called button via

        try {             process p = runtime.getruntime().exec("cgminer.exe" + " -o " + infos.address + ":" + infos.port + " -u " + infos.user + " -p " + infos.password);             p.waitfor();              string line;              bufferedreader error = new bufferedreader(new inputstreamreader(p.geterrorstream()));             while((line = error.readline()) != null){                 system.out.println(line);             }             error.close();              bufferedreader input = new bufferedreader(new inputstreamreader(p.getinputstream()));             while((line=input.readline()) != null){                 system.out.println(line);             }              input.close();              outputstream outputstream = p.getoutputstream();             printstream printstream = new printstream(outputstream);             printstream.println();             printstream.flush();             printstream.close();         }             catch (exception e) {                 // ...               }     }  } 

and output directed jtext with

public class customoutputstream extends outputstream {     private jtextarea textarea;      public customoutputstream(jtextarea textarea) {         this.textarea = textarea;     }      @override     public void write(int b) throws ioexception {         textarea.append(string.valueof((char) b));         textarea.setcaretposition(textarea.getdocument().getlength());     } } 

my problem when call first class button locks , no output makes jtext. when force close cgminer output appears.

any appreciated has brain warped.

my problem when call first class button locks , no output makes jtext. when force close cgminer output appears.

this classic symptom of tying swing event thread. when run long-running piece of code on swing event thread (also known edt or event dispatch thread), prevent thread doing chores including painting gui , interacting user, "freezing" gui.

the solution not comment waitfor() suggested, rather run , other blocking code in backgrounds thread such swingworker. when this, make sure take care update swing gui on event thread. swingworker has built-in way via publish , process methods.

for details on this, please check out concurrency in swing

you need more threading since lines of code blocking , prevent lines down stream running until unblock, important action done. instance these block:

// blocks p.waitfor();  // blocks both times use while((line = error.readline()) != null){   system.out.println(line); }