Java获取Linux下Top命令的执行结果

package com.ncs_cyber.util;

import Java.io.BufferedReader;
import java.io.File;
import java.io.FileWriter;
import java.io.InputStreamReader;
import java.util.Random;

public class GwUtil {
private static Random r = new Random();

/**
* 功能：执行CMD命令,返回命令结果
*/
public static String execByFile(String cmd) throws Exception {
String filename = null;
StringBuffer sb = new StringBuffer("");
BufferedReader bufferedReader = null;
Process process = null;
File file = null;
r.setSeed(99999);

if (cmd == null) {
return null;
}
try {
String ls_1;
// 生成临时文件，文件名随机
filename = "/tmp/gwtemp" + Long.toString(Math.abs(r.nextLong()))
+ ".sh";

file = new File(filename);
while (file.exists()) {
filename = "/tmp/gwtemp"
+ Long.toString(Math.abs(r.nextLong())) + ".sh";
file = new File(filename);
}
String execmd = new String("sh " + filename);// 执行文件的命令
FileWriter filewriter = new FileWriter(file, false);
filewriter.write("#! /bin/sh");
// Log.debug("do cmd:" + cmd + "\n");