如何讀取.conf檔案以及實時更新檔案内容

1.BaseFileConfig:

public abstract class BaseFileConfig {
  private FileReader fileReader;
  private BufferedReader bufferedReader ;
  

  
  public abstract void initConfiguration(String filePath);
//  public abstract String listConfiguration();
  protected abstract void setFileLastModified(long time);
  public abstract long getFileLastModified();
  
  
  protected BufferedReader readFile(String filePath) throws FileNotFoundException{
    File file = new File(filePath);
    //set file last modified Time
    long time = file.lastModified();
    setFileLastModified( time);
    
    //read file
    fileReader=new FileReader(file);
    bufferedReader = new BufferedReader(fileReader); 
    return bufferedReader;
  }
  
  protected void closeReadFile() throws IOException{
    if (bufferedReader!=null){
      bufferedReader.close();
    }
    if (fileReader!=null){
      fileReader.close();
    }
  }


}      

2.UserConfig.conf

public class UserConfig extends BaseFileConfig {

  private static Logger logger = LoggerFactory.getLogger(UserConfig.class);

  private static long lastModifiedTime = 0;
  private long startTime;
  private Map<String, UserInfo> users;
  private static boolean isReady = false;
  
  private static UserConfig instanced = new UserConfig();

  private UserConfig() {
    
    if (!isReady){
      isReady = true;
      String path = SystemConfig.getUser_conf_path();
      initConfiguration(path);
      
    }
  }

  public static UserConfig getInstanced() {
    
    return instanced;
  }

  @Override
  public void initConfiguration(String filePath) {
    // first step, read file
    // second step, init configuration
    // third step, close red file
    if (filePath == null) {
      logger.info("file path is null");
      return;
    }

    BufferedReader bf = null;
    Map<String, UserInfo> userMap = new HashMap<String, UserInfo>();
    try {
      bf = readFile(filePath);
      if (bf == null) {
        logger.info("file is empty");
        return;
      }
      String line = null;
      while ((line = bf.readLine()) != null) {
        String[] arr = line.split(",");

        if (arr.length == 2) {

          UserInfo userInfo = new UserInfo();
          userInfo.setUsername(arr[0]);
          userInfo.setPassword(arr[1]);

          userMap.put(arr[0].trim(), userInfo);
        }
      }

      if (userMap.size() > 0) {

        users = userMap;
      }

    } 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();
      } catch (IOException e) {
        logger.error("action:config;error message:" + e.getMessage());
      }
    }


  @Override
  protected void setFileLastModified(long time) {
    // TODO Auto-generated method stub
    lastModifiedTime = time;
  }

  @Override
  public long getFileLastModified() {
    // TODO Auto-generated method stub
    return lastModifiedTime;
  }

}      

}


  public Map<String, UserInfo> getUsers() {
    long endTime = System.currentTimeMillis();
    long readTime = endTime - startTime;
    
    if (readTime > Long.parseLong(SystemConfig.getProperty("user_conf.timeout.time")) * 1000){
      String path = SystemConfig.getUser_conf_path();
      File file = new File(path);
      long lastRead = file.lastModified();
      
      if (lastModifiedTime != lastRead) {
        initConfiguration(path);        
      } 
      startTime = endTime;
      
    }
    
    if(users != null){
           return users;
    }
    return null;
  }
  
  public UserInfo getUser(String userName){
    if (userName==null){
      return null;
    }
    if (users!=null){
      return users.get(userName);
    }
    
    return null;
  }