如何使用Java启动和关闭Tomcat服务器？

package com.calltomcat.test;
import java.io.bufferedreader;
import java.io.ioexception;
import java.io.inputstreamreader;
public class calltomcat {
 public static void main(string[] args) {
 //string command = "e:\apache-tomcat-7.0.76\bin\startup.bat";//启动tomcat命令
 //string command = "e:\apache-tomcat-7.0.76\bin\tomcat7w.exe";//启动tomcat命令，仅限windows版本，无弹框
 string command = "e:\apache-tomcat-7.0.76\bin\shutdown.bat";//关闭tomcat命令
 calltomcat calltomcat = new calltomcat();
 try {
  calltomcat.callcommand(command);
 } catch (ioexception e) {
  system.out.println("执行命令时出错：" + e.getmessage());
 }
 }
 /**
 * 执行命令
 * 
 * @throws ioexception
 */
 private void callcommand(string command) throws ioexception {
 runtime runtime = runtime.getruntime();//返回与当前的java应用相关的运行时对象
 //指示java虚拟机创建一个子进程执行指定的可执行程序，并返回与该子进程对应的process对象实例
 process process = runtime.exec(command);
 runtime.gc();//运行垃圾回收器
 string line = null;
 string content = "";
 bufferedreader br = new bufferedreader(new inputstreamreader(process.getinputstream()));
 while((line = br.readline()) != null) {
  content += line + "
";
 }
 system.out.println(content);
 }
}