读取.properties中的IPlist技巧

public class IpConfig {
  private static final Logger logger = LoggerFactory.getLogger(IpConfig.class);
  
  private static boolean isReady = false;
  
  private static IpConfig instanced = new IpConfig();  
  public static IpConfig getInstanced() {
    return instanced; 
  }
  
  private List<String> ip;
  long startTime;
  long lastModifiedTime;
  
  private IpConfig() {
    
    if (!isReady){
      isReady = true;
      String path = this.getClass().getResource(PropertiesUtil.getValue("ip.white.list.path")).getFile();
      initConfiguration(path);            
      startTime = System.currentTimeMillis();
    }
  }

  public void initConfiguration(String path) {
    File file = new File(path);
    
    if (!file.exists()) {
      logger.debug("file is null");
      return;
    }
    
    lastModifiedTime = file.lastModified();

    BufferedReader bf = null;
    FileReader fileReader = null;
    List<String> ipList = new ArrayList<String>();
    try {
      fileReader = new FileReader(file);
      bf = new BufferedReader(fileReader); 
      
      String line = null;
      while ((line = bf.readLine()) != null) {
        ipList.add(line.trim().replace(" ", ""));
      }
      
      if (ipList.size() > 0) {
        ip = ipList;
      }

    } catch (FileNotFoundException e) {
      logger.error("action:config;error message:" + e.getMessage());
    } catch (IOException e) {
      logger.error("action:config;error message:" + e.getMessage());
    } finally {
      try {
        closeReadFile(bf, fileReader);
      } catch (IOException e) {
        logger.error("action:config;error message:" + e.getMessage());
      }
    }
    
  }

  protected void closeReadFile(BufferedReader bufferedReader, FileReader fileReader) throws IOException{
    if (bufferedReader!=null){
      bufferedReader.close();
    }
    if (fileReader!=null){
      fileReader.close();
    }
  }
  
  public List<String> getIpList() {
    long endTime = System.currentTimeMillis();
    long readTime = endTime - startTime;
    
    if (readTime > Long.parseLong(PropertiesUtil.getValue("ip.timeout.time")) * 1000){
      String path = this.getClass().getResource(PropertiesUtil.getValue("ip.white.list.path")).getFile();
      File file = new File(path);
      long lastRead = file.lastModified();
      //If file had been modified, need to init again
      if (lastModifiedTime != lastRead) {
        initConfiguration(path);        
      } 
      startTime = endTime;
      
    }
    if (ip != null && ip.size() > 0) {
      return ip;
    }
    return null;
  }

}