import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
 
public class SysCommandExecutor
{
private ILogDevice fOuputLogDevice = null;
private ILogDevice fErrorLogDevice = null;
private String fWorkingDirectory = null;
private List fEnvironmentVarList = null;

private StringBuffer fCmdOutput = null;
private StringBuffer fCmdError = null;
private AsyncStreamReader fCmdOutputThread = null;
private AsyncStreamReader fCmdErrorThread = null;

public void setOutputLogDevice(ILogDevice logDevice)
{
fOuputLogDevice = logDevice;
}

public void setErrorLogDevice(ILogDevice logDevice)
{
fErrorLogDevice = logDevice;
}

public void setWorkingDirectory(String workingDirectory) {
fWorkingDirectory = workingDirectory;
}

public void setEnvironmentVar(String name, String value)
{
if( fEnvironmentVarList == null )
fEnvironmentVarList = new ArrayList();

fEnvironmentVarList.add(new EnvironmentVar(name, value));
}

public String getCommandOutput() {
return fCmdOutput.toString();
}

public String getCommandError() {
return fCmdError.toString();
}

public int runCommand(String commandLine) throws Exception
{
/* run command */
Process process = runCommandHelper(commandLine);

/* start output and error read threads */
startOutputAndErrorReadThreads(process.getInputStream(), process.getErrorStream());
    
/* wait for command execution to terminate */
int exitStatus = -1;
try {
exitStatus = process.waitFor();

} catch (Throwable ex) {
throw new Exception(ex.getMessage());

} finally {
/* notify output and error read threads to stop reading */
notifyOutputAndErrorReadThreadsToStopReading();
}

return exitStatus;
}

private Process runCommandHelper(String commandLine) throws IOException
{
Process process = null;
if( fWorkingDirectory == null )
process = Runtime.getRuntime().exec(commandLine, getEnvTokens());
else
process = Runtime.getRuntime().exec(commandLine, getEnvTokens(), new File(fWorkingDirectory));

return process;
}

private void startOutputAndErrorReadThreads(InputStream processOut, InputStream processErr)
{
fCmdOutput = new StringBuffer();
fCmdOutputThread = new AsyncStreamReader(processOut, fCmdOutput, fOuputLogDevice, "OUTPUT");
fCmdOutputThread.start();

fCmdError = new StringBuffer();
fCmdErrorThread = new AsyncStreamReader(processErr, fCmdError, fErrorLogDevice, "ERROR");
fCmdErrorThread.start();
}

private void notifyOutputAndErrorReadThreadsToStopReading()
{
fCmdOutputThread.stopReading();
fCmdErrorThread.stopReading();
}

private String[] getEnvTokens()
{
if( fEnvironmentVarList == null )
return null;

String[] envTokenArray = new String[fEnvironmentVarList.size()];
Iterator envVarIter = fEnvironmentVarList.iterator();
int nEnvVarIndex = 0; 
while (envVarIter.hasNext() == true)
{
EnvironmentVar envVar = (EnvironmentVar)(envVarIter.next());
String envVarToken = envVar.fName + "=" + envVar.fValue;
envTokenArray[nEnvVarIndex++] = envVarToken;
}

return envTokenArray;
}
}
 
class AsyncStreamReader extends Thread
{
private StringBuffer fBuffer = null;
private InputStream fInputStream = null;
private String fThreadId = null;
private boolean fStop = false;
private ILogDevice fLogDevice = null;

private String fNewLine = null;

public AsyncStreamReader(InputStream inputStream, StringBuffer buffer, ILogDevice logDevice, String threadId)
{
fInputStream = inputStream;
fBuffer = buffer;
fThreadId = threadId;
fLogDevice = logDevice;

fNewLine = System.getProperty("line.separator");
}

public String getBuffer() {
return fBuffer.toString();
}

public void run()
{
try {
readCommandOutput();
} catch (Exception ex) {
//ex.printStackTrace(); //DEBUG
}
}

private void readCommandOutput() throws IOException
{
BufferedReader bufOut = new BufferedReader(new InputStreamReader(fInputStream));
String line = null;
while ( (fStop == false) && ((line = bufOut.readLine()) != null) )
{
fBuffer.append(line + fNewLine);
printToDisplayDevice(line);
}
bufOut.close();
//printToConsole("END OF: " + fThreadId); //DEBUG
}

public void stopReading() {
fStop = true;
}

private void printToDisplayDevice(String line)
{
if( fLogDevice != null )
fLogDevice.log(line);
else
{
printToConsole(line);//DEBUG
}
}

private synchronized void printToConsole(String line) {
System.out.println(line);
}
}
 
class EnvironmentVar
{
public String fName = null;
public String fValue = null;

public EnvironmentVar(String name, String value)
{
fName = name;
fValue = value;
}
}