问Executor框架future.get()挂起

EN

Runtime runtime = Runtime.getRuntime();
proc = runtime.exec(command.toString());
ProcessHandler errorStream = new ProcessHandler(proc.getErrorStream(),"ERROR", rdyFilePath);
ExecutorService pool = Executors.newSingleThreadExecutor();
Future future = pool.submit(errorStream);
pool.shutdown();

try {
     if(future.get() == null) {
         log.info("Done completing error thread");
     }
} catch (InterruptedException | ExecutionException e) {
     e.printStackTrace();
}

public class ProcessHandler implements Callable<Integer> {

    private static Logger log = Logger.getLogger(ProcessHandler.class.getName());

    InputStream inpStr;
    String strType;
    String rdyFile;


    public ProcessHandler(InputStream inpStr, String strType, String rdyFile) {
        this.inpStr = inpStr;
        this.strType = strType;
        this.rdyFile = rdyFile;
    }

    public Integer call() throws FileMetadataException {
        StringBuffer sb = new StringBuffer();
        try {

            InputStreamReader inpStrd = new InputStreamReader(inpStr);
            BufferedReader buffRd = new BufferedReader(inpStrd);
            String line = null;
            while((line = buffRd.readLine()) != null) {
                if("ERROR".equalsIgnoreCase(strType)) {

                    sb.append(line + "\n");
                    log.info(strType + "->" + line);
                }
            }
            if(sb != null) {
                log.info("Error Stream length : " + sb.length());
                throw new RuntimeException();

            }

            buffRd.close();
        } catch(IOException e) {
            log.error("IOException in ProcessHandler Thread" + e.fillInStackTrace());
            System.err.println(e);
            throw new FileMetadataException();
        } finally {
            if(sb != null) {
                if(sb.toString().length() > 0 ) {
                    log.error("Error string buffer length " + sb.length());
                    // do not create rdy file
                } else {
                    log.error("Error string buffer length : " + sb.length());
                    File f = new File(rdyFile);
                        try {
                            f.createNewFile();
                        } catch(IOException e) {
                            log.error("IOException while creating rdy file");
                        }
                    }
                    // create rdy file. 
                }
            }
            return sb.length();
        }

    }
}