prod/net/jaekl/cfb/util/Command.java

   1 package net.jaekl.cfb.util;
   2
   3 import java.io.BufferedReader;
   4 import java.io.IOException;
   5 import java.io.InputStream;
   6 import java.io.InputStreamReader;
   7
   8 public class Command {
   9         public static class Result
  10         {
  11                 private int m_retCode;
  12                 private String m_stdout;
  13                 private String m_stderr;
  14
  15                 Result(int retCode, String stdout, String stderr) {
  16                         m_retCode = retCode;
  17                         m_stdout = stdout;
  18                         m_stderr = stderr;
  19                 }
  20
  21                 public int getRetCode() { return m_retCode; }
  22                 public String getStdout() { return m_stdout; }
  23                 public String getStderr() { return m_stderr; }
  24         }
  25
  26         private static class StreamGobbler extends Thread {
  27
  28                 private StringBuilder m_sb;
  29                 private BufferedReader m_br;
  30
  31                 public StreamGobbler(InputStream is) {
  32                         m_sb = new StringBuilder();
  33                         m_br = new BufferedReader(new InputStreamReader(is));
  34                 }
  35
  36                 @Override
  37                 public void run() {
  38                         String line;
  39                         try {
  40                                 line = m_br.readLine();
  41                                 while (null != line) {
  42                                         m_sb.append(line).append(System.lineSeparator());
  43                                         line = m_br.readLine();
  44                                 }
  45                         } catch (IOException exc) {
  46                                 m_sb.append(Util.stringify(exc));
  47                         }
  48                         finally {
  49                                 try {
  50                                         m_br.close();
  51                                 } catch (IOException exc) {
  52                                         m_sb.append(Util.stringify(exc));
  53                                 }
  54                         }
  55                 }
  56
  57                 public String getOutput() { return m_sb.toString(); }
  58         }
  59
  60         public Command()
  61         {
  62                 // no-op
  63         }
  64
  65         public Result exec(String cmd) throws IOException
  66         {
  67                 int retCode = 0;
  68                 String stdout = "";
  69                 String stderr = "";
  70
  71                 Process proc = doRuntimeExec(cmd);
  72                 assert( null != proc );
  73
  74                 StreamGobbler stdoutGobbler = new StreamGobbler(proc.getInputStream());
  75                 StreamGobbler stderrGobbler = new StreamGobbler(proc.getErrorStream());
  76
  77                 stdoutGobbler.start();
  78                 stderrGobbler.start();
  79
  80                 try {
  81                         retCode = proc.waitFor();
  82                         stdoutGobbler.join();
  83                         stderrGobbler.join();
  84
  85                         stdout = stdoutGobbler.getOutput();
  86                         stderr = stdoutGobbler.getOutput();
  87
  88                 } catch (InterruptedException exc) {
  89                         stderr += Util.stringify(exc);
  90                 }
  91
  92                 return new Result(retCode, stdout, stderr);
  93         }
  94
  95         Process doRuntimeExec(String cmd) throws IOException {
  96                 return Runtime.getRuntime().exec(cmd);
  97         }
  98 }