/** The JDBC database driver. */指定连接驱动 public static final String DB_DRIVER = "driver"; /** The JDBC database URL. */ 连接字符串 public static final String DB_URL = "URL"; /** The database user name. */ 用户名 public static final String DB_USE
先看一段错误日志: ### Error querying database. Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: No operations allowed after connection closed. ### The error may exist in file ----] ### The error may involve ..... ### The error occ