在java程序中调用操作系统的功能

在java程序中有时候需要调用操作系统的一些功能，特别是在unix/linux环境下，命令行提供了很多有用功能。

import java.io.*;   
  
/**  
* Description:  
*     get process input stream information  
* @version 1.0  
*  在java程序中有时候需要调用操作系统的一些功能，特别是在unix/linux环境下，命令行提供了很多有用功能。
*/  
  
class StreamGobbler extends Thread {   
      InputStream is;   
      String type;   
      String sInput;   
      String sLog;   
      StreamGobbler(InputStream is, String type) {   
          this.is = is;   
          this.type = type;   
          this.sInput = "";   
      }   
  
      public String getInput() {   
        return sInput;   
      }   
      public String getLog() {   
        return sLog;   
      }   
  
      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);   
                  sLog+=type + ">" + line+"<br>";   
                  sInput += line;   
              }   
  
          }   
          catch (IOException ioe){   
              ioe.printStackTrace();   
          }   
      }   
} 

import java.io.*;   
  
/**  
*    execute nativate command  
*    avaiable for win9x,winnt ,win2k,unix-like os  
*  
*/  
  
public class ExeShellCmd extends Thread{   
  
    private final static boolean  bDebug = true;
    public static final String WINDOWS_95 = "WINDOWS 95";
    public static final String WINDOWS_98 = "WINDOWS 98";
    public static final String WINDOWS_NT = "WINDOWS NT";
    public static final String WINDOWS_2K = "WINDOWS 2000";
    public static final String LINUX = "LINUX";
    public static final String SOLARIS = "SOLARIS";
    public static final String AIX = "AIX";
    public static final String FREEBSD = "FREEBSD";
    public static final String IRIX = "IRIX";
    public static final String HP_UX = "HP-UX";
  
    /**  
     * execute shell command according to OS  
     * @param sCmd command list  
     * @return echomessage  
     */  
    public static String exec(String[] sCmd){   
      System.out.println("execute commands:");   
      for(int i=0;i<sCmd.length;i++){   
        System.out.println(sCmd[i]);   
      }   
      String strRet="";   
      String sOS = System.getProperty( "os.name" ).toUpperCase();   
      if( sOS.equals(WINDOWS_2K) || sOS.equals(WINDOWS_NT) )   
        strRet=execInWinNT(sCmd);   
      if( sOS.equals(WINDOWS_95) || sOS.equals(WINDOWS_98) )   
        strRet=execInWin9x(sCmd);   
      if( sOS.equals(LINUX) || sOS.equals(FREEBSD) || sOS.equals(AIX) || sOS.equals(IRIX) || sOS.equals(SOLARIS) || sOS.equals(HP_UX) )   
        strRet=execInUNIX(sCmd);   
       return strRet;   
    }   
  
    public static String exec(String sCmd){   
      String[] sCmds = new String[1];   
      sCmds[0] = sCmd;   
      return exec(sCmds);   
    }   
  
    /**  
     * win9x  
     */  
    private static String execInWin9x(String sCmd[]){   
      String strRet="";   
      try{   
        Runtime aRT = Runtime.getRuntime(); // Runtime.getRuntime();   
        //Spawn a shell sub-process  
        Process aProc = aRT.exec( "command.com" );   
        strRet = exec(aProc,sCmd);   
      }catch(IOException ex){if(bDebug) System.out.println("ExeShellCmd.execInWin9x:error");};   
       return strRet;   
    }   
  
    /**  
     * winNT, win2000  
     */  
    private static String execInWinNT(String sCmd[]){   
      String strRet="";   
      try{   
        Runtime aRT = Runtime.getRuntime(); // Runtime.getRuntime();   
        //Spawn a shell sub-process 
        Process aProc = aRT.exec( "cmd.exe" );   
        strRet = exec(aProc,sCmd);   
      }catch(IOException ex){if(bDebug) System.out.println("ExeShellCmd.execInWinNT:error");};   
       return strRet;   
    }   
  
    /**  
     *     UNIX  
     */  
    private static String execInUNIX(String sCmd[]){   
      String strRet="";   
      try{   
        Runtime aRT = Runtime.getRuntime(); // Runtime.getRuntime();   
        //Spawn a shell sub-process 
        Process aProc = aRT.exec( "bash" );   
        strRet = exec(aProc,sCmd);   
      }catch(IOException ex){if(bDebug) System.out.println("ExeShellCmd.execInUNIX:error"+ex.getMessage()+"<br>");};   
      return strRet;   
    }   
  
    /**  
     * General Exe method  
     */  
    private static String exec(Process aProc,String sCmd[]){   
      String strRet="";   
      try{   
        strRet="";   
        // any error message?   
        StreamGobbler errGrobbler=new StreamGobbler(aProc.getErrorStream(), "ERROR");   
        errGrobbler.start();   
        System.out.println("ExeShellCmd.cmd : error " +errGrobbler.getLog());   
        // any output?  input   
        StreamGobbler outputGrobbler=new StreamGobbler(aProc.getInputStream(), "OUTPUT");   
        outputGrobbler.start();   
        PrintWriter shell = new PrintWriter(aProc.getOutputStream());   
        for(int i=0; i<sCmd.length; i++){   
          if (bDebug) {   
              System.out.println("ExeShellCmd.cmd : output " +sCmd[i]);   
          }   
          shell.println(sCmd[i]);   
          shell.flush();   
        }   
        shell.close();   
  
        int exitVal = aProc.waitFor();   
        String strErr= errGrobbler.getLog();   
        String strOut=outputGrobbler.getLog();   
        if((strErr!=null) && !(strErr.equals(""))){   
          strRet+=strErr;   
        }   
        if((strOut!=null) && !(strOut.equals(""))){   
          strRet+=strOut;   
        }   
        if(bDebug) {   
          System.out.println("ExitValue : " + exitVal);   
        }   
      }   
      catch(Exception ioex){   
        if(bDebug) {   
          System.out.println("ExeShellCmd: io error");   
        }   
      }   
      return strRet;   
    }   
  
}