做一个单子模式的类，只加载一次属性文件

import java.io.FileInputStream; 
import java.io.FileNotFoundException; 
import java.io.IOException; 
import java.io.InputStream; 
import java.util.Properties; 
/** 
*@authorleno 
*单子模式，保证在整个应用期间只加载一次配置属性文件 
*/ 
public class Singleton { 

    private static Singleton instance; 
    private static final String CONFIG_FILE_PATH = "E:\\config.properties"; 
    private Properties config; 
    private Singleton() { 
      config = new Properties(); 
      InputStream is; 
      try { 
          is = new FileInputStream(CONFIG_FILE_PATH); 
          config.load(is); 
          is.close(); 
      } catch (FileNotFoundException e) { 
          // TODO Auto-generated catch block 
          e.printStackTrace(); 
      } catch (IOException e) { 
          // TODO Auto-generated catch block 
          e.printStackTrace(); 
      } 
    } 
    public static Singleton getInstance() { 
      if(instance==null) { 
          instance = new Singleton(); 
      } 
      return instance; 
    } 
    public Properties getConfig() { 
      return config; 
    } 
    public void setConfig(Properties config) { 
      this.config = config; 
    } 
   
}