独立线程监控配置文件是否变更，适用于更新了配置文件，不需要重启tomcat服务

直接贴出来代码:

 package cn.leadeon.utils.file;

 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.util.Properties;

 /**
  * 轮询监控配置文件是否更新，动态获取最新内容
  *
  * @author LiJunJun
  * @date 2018.08.08
  */
 public class MonitorSysPropertiesUtil
 {
     private static Properties SysLocalPropObject = null;

     // 配置文件绝对路径
     private static String defaultPropFilePath = null;

     // 配置文件名称
     private static String propertiesName = null;

     // 文件更新标识
     protected long lastModifiedData = -1;

     private static MonitorSysPropertiesUtil instance;

     public static MonitorSysPropertiesUtil getInstance(String fileName)
     {
         if (propertiesName == null)
         {
             propertiesName = fileName;
         }

         if (instance == null)
         {
             syncInit();
         }

         return instance;
     }

     /**
      * 同步块，避免多线程调用，生成多个实例
      */
     private static synchronized void syncInit()
     {
         if (instance == null)
         {
             instance = new MonitorSysPropertiesUtil();
         }
     }

     /**
      * 私有构造器启动一个线程实时监控配置文件
      */
     private MonitorSysPropertiesUtil()
     {
         SysLocalPropObject = new Properties();

         ClassLoader classLoader = MonitorSysPropertiesUtil.class.getClassLoader();

         defaultPropFilePath = classLoader.getResource(propertiesName).getFile();

         File propertyFile = new File(defaultPropFilePath);

         if (propertyFile.exists())
         {
             reloadFile(propertyFile);
         }

         // 循环监控配置文件的变化，一旦发现文件发生变化了则重读配置文件
         Thread thread = new Thread(new monitorRunnable(defaultPropFilePath));

         thread.start();
     }

     /**
      * 监控线程内部类
      *
      * @author LiJunJun
      */
     class monitorRunnable implements Runnable
     {

         private String filePath;

         final MonitorSysPropertiesUtil self = MonitorSysPropertiesUtil.this;

         public monitorRunnable(String filePath)
         {
             this.filePath = filePath;
         }

         @Override
         public void run()
         {
             while (true)
             {
                 // 间隔10分钟
                 try
                 {
                     Thread.sleep(1000 * 60 * 10);
                     // Thread.sleep(1000);
                 }
                 catch (InterruptedException e)
                 {
                     System.out.println("定时巡检配置文件线程休眠异常" + Thread.currentThread().getName());
                     e.printStackTrace();
                 }

                 try
                 {
                     File propertyFile = new File(filePath);

                     if (self.lastModifiedData != propertyFile.lastModified())
                     {
                         self.reloadFile(propertyFile);
                         self.lastModifiedData = propertyFile.lastModified();
                     }
                 }
                 catch (Exception e)
                 {
                     System.out.println("校验配置文件是否改变异常,MonitorSysPropertiesUtil -- monitorRunnable");
                     e.printStackTrace();
                 }
             }
         }

     }

     /**
      * 重新加载文件
      *
      * @author LiJunJun 2017.08.08
      * @param propertyFile 配置文件路径
      */
     private void reloadFile(File propertyFile)
     {
         FileInputStream inputStreamLocal = null;
         try
         {
             inputStreamLocal = new FileInputStream(propertyFile);

             SysLocalPropObject.load(inputStreamLocal);
         }
         catch (Exception e)
         {
             if (e instanceof FileNotFoundException)
             {
                 SysLocalPropObject = null;
             }
             else
             {
                 System.out.println("校验配置文件是否改变异常,MonitorSysPropertiesUtil -- reloadFile failed");
             }
             e.printStackTrace();
         }
         finally
         {
             try
             {
                 if (inputStreamLocal != null)
                 {
                     inputStreamLocal.close();
                 }
             }
             catch (IOException e)
             {
                 System.out.println("关闭IO流异常,MonitorSysPropertiesUtil -- reloadFile failed");
                 e.printStackTrace();
             }
         }
     }

     /**
      * 对外提供获取配置文件对象的方法
      */
     public static Properties getPropertiesObject()
     {
         return SysLocalPropObject;
     }
 }