我的问题是，当我在ide（如eclipse）中使用这段代码时，它工作得很好，但当我在tomcat服务器中使用它时，它不工作这是javaservlet应用程序的一部分（我不使用maven或spring…）

public class DAOFactory {
    private final static String PROPERTY_DRIVER = "driver";
    private final static String PROPERTY_USER_NAME = "userName";
    private final static String PROPERTY_PASSWD = "passwd";
    private final static String PROPERTY_DB_NAME = "dbName";
    private final static String PROPERTY_URL = "url";
    private final static String FILE_PROPERTIES = "/com/DAO/dbInfos.properties";

    private String url;
    private String passwd;

    private String userName;

    /**
     * 
     * @param url
     * @param passwd
     * @param userName
     */
    public DAOFactory(String url,String passwd,String userName)
    {
        this.url = url;
        this.passwd = passwd;
        this.userName = userName;
    }
    /**
     * 
     * @return
     * @throws DAOConfigurationException
     */
    public static DAOFactory getInstance()throws DAOConfigurationException
    {
        Properties properties = new Properties();
        String passwd;
        String url;
        String userName;
        String driver ;

        ClassLoader loader = Thread.currentThread().getContextClassLoader();
        InputStream input  = loader.getResourceAsStream(FILE_PROPERTIES);

        if(input == null)
            throw new DAOConfigurationException("properties file not exist EXCEPTION");
        try
        {
            properties.load(input);

            url = properties.getProperty(PROPERTY_URL);
            passwd = properties.getProperty(PROPERTY_PASSWD);

            userName = properties.getProperty(PROPERTY_USER_NAME);
            driver = properties.getProperty(PROPERTY_DRIVER);   
        }
        catch(IOException e)
        {
            throw new DAOConfigurationException("properties file loading EXCEPTION ",e);
        }

        try
        {
            Class.forName(driver);
        }
        catch(ClassNotFoundException e)
        {
            throw new DAOConfigurationException("------------- driver loading error ",e);
        }

        return new DAOFactory(url,passwd,userName);
    }

    public Connection getConnection()throws DAOConfigurationException
    {
        try
        {
            return DriverManager.getConnection(url,userName,passwd);
        }catch(SQLException e)
        {
            throw new DAOConfigurationException("connection failed to be created",e);
        }
    }

    /**
     * 
     * @return
     */
    public UniteDAO getUnite()
    {
        return new UniteImplDAO(this);
    }
}

总是在上面的if语句中抛出“properties file not exist exception”消息
包的层次结构是

src
 |_ com
    |_ DAO
        |_ DAOFactory
        |_ dbInfos.properties 
WEB-INF
  |_ 
      .
      .
      .

请你帮忙：）