process两种用法（一）

package interview.process;

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

public class ProcessUsual
{
	public static void main(String[] args)
	{
		call("javac");
		call("cmd.exe /C dir");
	}

	public static void call(String cmd)
	{
		Runtime rt = Runtime.getRuntime();

		Process pro = null;
		try
		{
			pro = rt.exec(cmd);

			// =======在waitfor之前必须调用这两个方法======//
			new StreamTool(pro.getInputStream()).start();
			new StreamTool(pro.getErrorStream()).start();
			// ===================================//

			pro.waitFor();
		}
		catch (InterruptedException e)
		{
			e.printStackTrace();
		}
		catch (IOException e)
		{
			e.printStackTrace();
		}

		System.out.println(pro.exitValue());
	}

	private static class StreamTool extends Thread
	{
		BufferedReader br = null;

		public StreamTool(InputStream is)
		{
			br = new BufferedReader(new InputStreamReader(is));
		}

		public void run()
		{
			String line = null;

			try
			{
				while ((line = br.readLine()) != null)
				{
					System.out.println(line);
				}
			}
			catch (IOException e)
			{
				e.printStackTrace();
			}
		}
	}
}