按条件删除ES中的数据 POST book/novel/_delete_by_query{"query":{"match":{"title": "标题"}}} 按id删除ES中的数据 DELETE book/novel/teQj4HgB7a7ttft0hVBP 新增时设置id POST book/novel/1{"title": "三国演义","author": "罗贯中","

jdbcUtil02.java   //单例模式public final class jdbcUtil02 { static String url = "jdbc:mysql://localhost:3306/jdbc"; static String username = "root"; static String password = "root";  //private static jdb