java执行shell命令

import java.io.IOException;

public class ShellCommand
{
	public static void execCmd(String cmd)
	{
		execCmd(cmd, null);
	}
	
	public static void execCmd(String cmd, StringBuffer sb)
	{
		Process process = null;
		try {
			process = Runtime.getRuntime().exec(cmd);
			getProcessOutput(process, sb);
		} catch (Exception e) {
			if (sb != null) {
				sb.append("executeCmd: " + cmd + "\n");
				sb.append("errorMessage: " + e.toString() + "\n");
			}
		}
		if (process != null) {
			try {
				process.waitFor();
				process.getOutputStream().close();
				process.getErrorStream().close();
				process.getInputStream().close();
			} catch (InterruptedException e) {
				e.printStackTrace();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}
	
	private static void getProcessOutput(Process process, StringBuffer sb)
	{
		if (process == null) {
			return;
		}
		StreamCaptureThread errorStream = new StreamCaptureThread(process.getErrorStream());
		StreamCaptureThread inputStream = new StreamCaptureThread(process.getInputStream());
		errorStream.setOutput(sb);
		inputStream.setOutput(sb);
		new Thread(errorStream).start();
		new Thread(inputStream).start();
	}
}

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

public class StreamCaptureThread implements Runnable
{
	InputStream m_in;
	StringBuffer m_sb;

	public StreamCaptureThread(InputStream inputStream)
	{
		this.m_in = inputStream;
	}

	public void setOutput(StringBuffer sb)
	{
		m_sb = sb;
	}

	public void run()
	{
		try {
			BufferedReader br = new BufferedReader(new InputStreamReader(m_in));
			String line = null;
			while (m_in != null && (line = br.readLine()) != null) {
				if (line.trim().length() > 0) {
					if (m_sb != null) {
						m_sb.append(line);
						m_sb.append("\n");
					}
				}
			}
		} catch (IOException ex) {
			ex.printStackTrace(System.err);
		}
	}
}