java调用dos命令

package com;

import java.io.BufferedReader;
import java.io.InputStreamReader;

public class CommonUtils {
	
	public static String exeCMD1(String cmd){
		cmd = "cmd.exe /c "+cmd;
		Process process = null;
		StringBuffer sb = new StringBuffer();
		BufferedReader reader = null;
		
		try {
			process = Runtime.getRuntime().exec(cmd);
			reader = new BufferedReader(new InputStreamReader(process.getInputStream()));
			while(true){
				String str = reader.readLine();
				if(str==null) break;
				System.out.println(str);
				sb.append(str);
			}
			
			process.destroy();
		} catch (Exception e) {
			// TODO: handle exception
		}
		return sb.toString();
	}
	public static String exeCMD2(String cmd){
		String[] args = new String[]{"cmd","/c",cmd};  
		Process process = null;
		StringBuffer sb = new StringBuffer();
		BufferedReader reader = null;
		
		try {
			process = Runtime.getRuntime().exec(args);
			reader = new BufferedReader(new InputStreamReader(process.getInputStream()));
			while(true){
				String str = reader.readLine();
				if(str==null) break;
				System.out.println(str);
				sb.append(str);
			}
			
			process.destroy();
		} catch (Exception e) {
			// TODO: handle exception
		}
		return sb.toString();
	}
	
	public static void main(String[] args){
		CommonUtils.exeCMD1("tree");
		CommonUtils.exeCMD1("tree");
	}

}