Java Web Learning Notes - mybatis-07-dao development and use (mapper agent development)

Need to write mapper interface (equivalent to dao interface) mapper.xml mapping file needs to be written mybatis can automatically generate proxy objects of mapper interface implementation classes Development specification 1. namespace in mapper.xml is equal to the address of mapper interface 2. The method name in the mapper.java interfac ...

Added by Zomie on Fri, 01 May 2020 01:27:37 +0300

Using PhotoView to view pictures

The project needs to realize the function of picture viewing. Using ImageView can't scale, using the system's picture viewer can't meet their own customized needs, so I used Viewpager + PhotoView to realize it. Introducing PhotoView Github link for PhotoView , PhotoView is designed to help developers easily scale Android ImageView. 1. Conf ...

Added by yanisdon on Thu, 30 Apr 2020 17:22:01 +0300

Awesome, the asynchronous processing mechanism of Servlet3

Servlet3 has been released for several years. How many people know its new features? Here is a brief introduction. The following features are mainly added: 1. Asynchronous processing support 2. Pluggability support 3. Annotation support, zero configuration, no need to configure web.xml ... What the hell is asynchronous processing? Operate the k ...

Added by JamieWAstin on Wed, 29 Apr 2020 19:20:32 +0300

A good paging plug-in of Mybatis com.github.pagehelper

1. Need to import the jar package of PageHelper If maven is not used, just import the jar package into the lib folder. The PageHelper plug-in has open source on github, Address: https://github.com/pagehelper/Mybatis-PageHelper/tree/master/src/main/java/com/github/pagehelper.   If maven is used, the plug-in can be introduced in pom.xml as fol ...

Added by Arnerd on Wed, 29 Apr 2020 18:57:15 +0300

Getting started with Java Web listener

monitor Catalog OnlineCountListener.java package com.huangdekai.JavaWeb.listener; import javax.servlet.ServletContext; import javax.servlet.http.HttpSessionEvent; import javax.servlet.http.HttpSessionListener; /** * @Autord: HuangDekai * @Date: 2020/4/28 22:41 * @Version: 1.0 * @since: jdk11 */ public class OnlineCountListener imple ...

Added by vin_akleh on Wed, 29 Apr 2020 18:08:47 +0300

File upload Spring MVC cross server

prerequisite The value of enctype of form must be multipart / form data. The function of enctype is the type of request body method must be post Need to have < input type = "file" / > tag To implement a file using the Commons file upload component, you need to import the corresponding supporting jar package of the comp ...

Added by elle_girl on Tue, 28 Apr 2020 19:17:11 +0300

MyBatis L2 cache implementation details and precautions

Introduction to L2 cache In the first level cache mentioned above, the largest sharing range is within a SqlSession. If multiple sqlsessions need to share cache, they need to use the second level cache. After the second level cache is enabled, the cachenexecutor will be used to decorate the Executor. Before entering the query process of the fir ...

Added by sabien on Mon, 27 Apr 2020 12:20:29 +0300

python realizes the wechat automatic reminder function of seckill goods (with code)

Technology realization principle: get the specific commodity information of JD, and then use wechat to send reminders Tool: two microsignals are needed, which are mutual friends If you want to learn Python or are learning python, there are many Python tutorials, but are they up to date? Maybe you have learned something that someone else probabl ...

Added by Pastulio on Mon, 27 Apr 2020 10:54:48 +0300

A process of Spring Bean from scratch

There is a beginning but no end Experienced the history of java development, from the early writing of native servlet s, self-developed mvc and jdbc tools, and the use of open-source framework struts, hibernate, jsp, spring, springmvc, freemaker, springboot, to the final front and back-end separate development, the first development tool is e ...

Added by robinas on Fri, 24 Apr 2020 09:45:41 +0300

Transaction control configuration based on xml file

Configure transaction manager <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"> <property name="driverClassName" value="com.mysql.jdbc.Driver"></property> <property name="url" value="jdbc:mysql://localhost:3306/myword"></property> <property name="username" ...

Added by blt2589 on Tue, 21 Apr 2020 06:49:54 +0300