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

   1 package net.jaekl.cfb.util;
   2
   3 // Copyright (C) 2015 Christian Jaekl
   4
   5 import java.io.BufferedReader;
   6 import java.io.IOException;
   7 import java.io.InputStream;
   8 import java.io.InputStreamReader;
   9 import java.nio.charset.Charset;
  10 import java.nio.charset.IllegalCharsetNameException;
  11 import java.nio.charset.UnsupportedCharsetException;
  12
  13 public class Command {
  14         public static final String UTF_8 = "UTF-8";
  15         private Charset m_charset;
  16
  17         public static class Result
  18         {
  19                 private int m_retCode;
  20                 private String m_stdout;
  21                 private String m_stderr;
  22
  23                 Result(int retCode, String stdout, String stderr) {
  24                         m_retCode = retCode;
  25                         m_stdout = stdout;
  26                         m_stderr = stderr;
  27                 }
  28
  29                 public int getRetCode() { return m_retCode; }
  30                 public String getStdout() { return m_stdout; }
  31                 public String getStderr() { return m_stderr; }
  32         }
  33
  34         private class StreamGobbler extends Thread {
  35
  36                 private StringBuilder m_sb;
  37                 private BufferedReader m_br;
  38
  39                 public StreamGobbler(InputStream is) {
  40                         m_sb = new StringBuilder();
  41                         m_br = new BufferedReader(new InputStreamReader(is, m_charset));
  42                 }
  43
  44                 @Override
  45                 public void run() {
  46                         String line;
  47                         try {
  48                                 line = m_br.readLine();
  49                                 while (null != line) {
  50                                         m_sb.append(line).append(System.lineSeparator());
  51                                         line = m_br.readLine();
  52                                 }
  53                         } catch (IOException exc) {
  54                                 m_sb.append(Util.stringify(exc));
  55                         }
  56                         finally {
  57                                 try {
  58                                         m_br.close();
  59                                 } catch (IOException exc) {
  60                                         m_sb.append(Util.stringify(exc));
  61                                 }
  62                         }
  63                 }
  64
  65                 public String getOutput() { return m_sb.toString(); }
  66         }
  67
  68         public Command()
  69         {
  70                 try {
  71                         m_charset = Charset.forName(System.getProperty("file.encoding", UTF_8));
  72                 }
  73                 catch (IllegalCharsetNameException | UnsupportedCharsetException exc) {
  74                         m_charset = Charset.forName(UTF_8);
  75                 }
  76         }
  77
  78         public Result exec(String cmd) throws IOException
  79         {
  80                 int retCode = 0;
  81                 String stdout = "";
  82                 String stderr = "";
  83
  84                 Process proc = doRuntimeExec(cmd);
  85                 assert( null != proc );
  86
  87                 StreamGobbler stdoutGobbler = new StreamGobbler(proc.getInputStream());
  88                 StreamGobbler stderrGobbler = new StreamGobbler(proc.getErrorStream());
  89
  90                 stdoutGobbler.start();
  91                 stderrGobbler.start();
  92
  93                 try {
  94                         retCode = proc.waitFor();
  95                         stdoutGobbler.join();
  96                         stderrGobbler.join();
  97
  98                         stdout = stdoutGobbler.getOutput();
  99                         stderr = stdoutGobbler.getOutput();
 100
 101                 } catch (InterruptedException exc) {
 102                         stderr += Util.stringify(exc);
 103                 }
 104
 105                 return new Result(retCode, stdout, stderr);
 106         }
 107
 108         Process doRuntimeExec(String cmd) throws IOException {
 109                 return Runtime.getRuntime().exec(cmd);
 110         }
 111 }