HandlerExceptionResolver interface custom exception
Use @ ExceptionHandler annotation
File upload and download
If it's a picture, please refer to another Spring boot spring boot single / multi image upload and echo
1.SimpleMappingExceptionResolver cl ...
Posted on Tue, 18 Feb 2020 04:17:23 -0800 by greenba
Section 367, Python Distributed Crawler Build Search Engine Scrapy Lecture - elasticsearch (search engine) scrapy writes data to elasticsearch
The elasticsearch operations mentioned earlier, such as adding, deleting, altering, and searching, all use the language commands of elasticsearch, just like sql ...
Posted on Mon, 17 Feb 2020 18:39:27 -0800 by robkir
The table creation statement is as follows
To create a table:
-- Table structure for a_table
DROP TABLE IF EXISTS `a_table`;
CREATE TABLE `a_table` (
`id` smallint(6) AUTO_INCREMENT,
`name` varchar(10) Not NULL,
`phone` varchar(11) ...
Posted on Sun, 16 Feb 2020 22:47:27 -0800 by formxshape
A detailed explanation of foreach statement of MyBatis
foreach is mainly used to build in conditions. It can iterate a set in SQL statements.
Properties of foreach element
It mainly includes item, index, collection, open, separator, close
Alias of each element in the item collection when iterating
Posted on Sun, 16 Feb 2020 01:56:11 -0800 by nicephotog
Index the associated fields.
The specific analysis is as follows:
Give an example:
Form: training student form, class registration form
Demand: find out which classes the students have reported
The two tables have an associated field "CD" (Student ID).
`t_px_stu`.`PX_STU_PK` AS `PX_STU_PK ...
Posted on Sat, 15 Feb 2020 10:42:37 -0800 by ss-mike
Please pay attention to the version before using. My tomcat is version 9.0, and the notes in it are less, which may be more laborious for novices.
First, create a demo database and then a user table in Mysql. The code is as follows
create database Demo default charset=utf8;
create table user ...
Posted on Sat, 15 Feb 2020 08:24:16 -0800 by Webbyturtle
Summary of pain points
When we are de bug ging and need to see the complete sql, we can get the sql as shown in the figure in the console
Then manually replace the question mark placeholders one by one and go to MySQL to see if there is any problem with sql. If the sql is simple, it's easier to say. If it's a complex sql, manually replace N qu ...
Posted on Sat, 15 Feb 2020 08:17:40 -0800 by nilansanjaya
1, The architecture of Servlet
2.GenericServlet: abstract class
The other methods in the Servlet interface are implemented by default, and only the servlet() method is abstracted.
When defining Servlet classes in the future, you can inherit GenericServlet and implement servlet() m ...
Posted on Sat, 15 Feb 2020 01:15:07 -0800 by lawnninja
There is a problem in synthesizing the jdbc operations in the previous several articles, that is, too many repetitive steps need to be written, which wastes time, so you can write a jdbc tool class, encapsulate some repetitive code, and call directly when necessary
1. Write the JdbcUtil class as ...
Posted on Fri, 14 Feb 2020 07:11:48 -0800 by p2003morris
I recently used the DateTime object and wrote something like this:
DateTime dt = DateTime.Now;
return dt; // still today's date! WTF?
The intellisense document for AddDays() says it added a day to the date, but it doesn't - it actually returns the day it added, so you have to write it as:
DateTime dt = DateTime.Now;
dt = ...
Posted on Fri, 14 Feb 2020 01:57:32 -0800 by gcussi