Runtime.getRuntime().exec 类 防止阻塞

import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.util.ArrayList;
import java.util.List;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.apache.log4j.Logger;
import org.richinfo.gather.driver.MainEntry;
//用两个线程来分别获取标准输出流和错误输出流,否则会造成io阻塞导致程序卡死
public class ShellExec {

	public static String execute(String cmd) throws IOException, InterruptedException {
		StringBuffer sb = new StringBuffer();

		final Process p = Runtime.getRuntime().exec(cmd);

	    /*为"错误输出流"单独开一个线程读取之,否则会造成标准输出流的阻塞*/
        Thread t=new Thread(new InputStreamRunnable(p.getErrorStream(),"ErrorStream"));
        t.start();  

	    BufferedReader reader = null;
	    InputStream output = p.getInputStream();
	    //InputStream error = p.getErrorStream();
	    String line = "";

	    reader = new BufferedReader(new InputStreamReader(output));
	    while ((line = reader.readLine())!= null) {
	    		sb.append(line + "\n");
	    }
	    p.waitFor();
//	    if (0x00 == sb.length()) {
//	    	reader = new BufferedReader(new InputStreamReader(error));
//
//	    	while ((line = reader.readLine())!= null) {
//	    		sb.append(line + "\n");
//		    }
//	    }
	    reader.close();
	    p.destroy();
	    return sb.toString();
	}
}
/**读取InputStream的线程*/
class InputStreamRunnable implements Runnable
{
    BufferedReader bReader=null;
    String type=null;
    public InputStreamRunnable(InputStream is, String _type)
    {
        try
        {
            bReader=new BufferedReader(new InputStreamReader(new BufferedInputStream(is),"UTF-8"));
            type=_type;
        }
        catch(Exception ex)
        {
        }
    }
    public void run()
    {
        String line;
        int lineNum=0;  

        try
        {
            while((line=bReader.readLine())!=null)
            {
                lineNum++;
                //Thread.sleep(200);
            }
            bReader.close();
        }
        catch(Exception ex)
        {
        }
    }
}