JAVA执行cmd命令方法

package com.cmd;
 
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
 
public class Test {
 
    /**
     * 调用方法
     * @param cmd cmd命令
     * @return
     */
    public static String exec(String cmd) {
        try {
            Runtime rt = Runtime.getRuntime();
            Process proc = rt.exec(cmd);
            InputStream es = proc.getErrorStream();
            String line;
            BufferedReader br;
            br = new BufferedReader(new InputStreamReader(es, "GBK"));
            StringBuffer buffer=new StringBuffer();
            while ((line = br.readLine()) != null) {
                buffer.append(line+"\n");
            }
            return buffer.toString();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }
 
    public static void main(String[] args) {
        System.out.println(exec("java -version"));
    }
}