Tag:data source

  • Write mybatis from scratch (3) JDBC pool realizes database connection pool from zero

    Time:2020-11-30

    Prospect review In the MVP version, we have implemented a basic running mybatis. Section 2 handwritten mybatis from scratch (2) detailed explanation of mybatis interceptor plug-in mechanism In this section, let’s take a look at how to implement a database connection pool. Why do I need connection pooling? The creation of database connection is a […]

  • Mybatis source code analysis (5): getting sqlsession

    Time:2020-11-29

    The next step in building the sqlsessionfactory is to obtain the sqlsession. The code is as follows: SqlSession sqlSession = sqlSessionFactory.openSession(); Sqlsessionfactory has two implementation classes, sqlsessionmanager and defaultsqlsessionfactory.As can be seen from the last article, in the SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream); In, a defaultsqlsessionfactory object is added. Let’s introduce the main methods of […]

  • Android | Tangram dynamic page Road (6) data separation

    Time:2020-11-29

    After the first five series of articles, we have a preliminary understanding of Tangram and vlaayoutCombined with business scenariosUse, explore the support that framework capabilities can bring to the business. Because the research itself is a process that needs constant stepping on the pit, the outline is also fine tuned, and the follow-up will be […]

  • Spark as ETL tool combined with sequoiadb

    Time:2020-11-25

    1、 Preface The term ETL is often used in data warehouse, but its object is not limited to data warehouse. ETL refers to the process of extracting, transforming and loading data from the source system to the target data store. Common ETL tools include Oracle data integrator, Informatica powercenter, Datastage, kettle, datasprider, etc. In big […]

  • A small online chat program based on springboot and websocket

    Time:2020-11-23

    A small online chat program based on springboot and websocket (I haven’t written anything for several days, and I haven’t been practicing. I just read this Project description This project is a small demo of chatting, which is developed by springboot + websocket + Vue. One of the interfaces is to add friends. Adding friends […]

  • Recommend a good open source report platform — jnpf visualization platform

    Time:2020-11-22

    Jnpf visual development platformIt is an online report platform integrating report design and large screen design. It is easy to use and can help users design pages like excel. Using jnpf report platform, users can not only design a cool big screen in 10 minutes, but also quickly make various reports on the platform to […]

  • C ා RDLC continuous printing bar code

    Time:2020-11-21

    Using RDLC to realize bar code continuous printingImportant point: RDLC needs to add row group, print data source and pass it into list.Steps:1. VS2010, select the directory to be added, right-click to add a new item, select the report, and name it what you need, such as a.rdlc.2. Drag a table from the toolbox, name […]

  • Flexible use of IEnumerable interface and iqueryable interface

    Time:2020-11-19

    All functions of LINQ are basically based on the IEnumerable < T > interface type. It is OK to use IEnumerable < T > interface to process local collection. When the scene is switched to a remote data source, all remote data must be read to the local. When the data volume is small, the […]

  • FAQ of spring boot plus FAQ (12)

    Time:2020-11-15

    Spring boot plus FAQ Compile error problem Log compilation error Compilation tips log.info Etc. log error solve Check if the Lombok plug-in is installed Idea install Lombok Eclipse installing Lombok Run error problem MySQL error 2019-07-31 14:16:52.412 ERROR 14724 — [ main] com.alibaba.druid.pool.DruidDataSource : init datasource error, url: jdbc:mysql://localhost:3306/spring_boot_plus?serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=utf8&useSSL=false&allowPublicKeyRetrieval=true com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure The last […]

  • Tips | Flink sink schema field design tips

    Time:2020-11-14

    Each article in this series is relatively short and updated from time to time. Starting from some practical cases, this article aims to improve the posture of small partners A kind of Potential level. This article introduces the Flink sink schema field design tips, reading time is about 2 minutes, do not say much, directly […]

  • [deployment of springboot project to docker] 2. Build a simple project with springboot + mybatis + Druid

    Time:2020-11-11

    Write it at the front This article talks about the simple project of springboot + mybatis + Druid. If you have talked about the content of the last article, you can read my last article first[deployment of springboot project to docker] 1. Build an Ubuntu docker environment Springboot! Simplify, simplify, simplify! Springboot is designed to […]

  • Tips | Flink uses union instead of join and cogroup

    Time:2020-11-9

    Each article in this series is relatively short and updated from time to time. Starting from some practical cases, this article aims to improve the posture of small partners A kind of Potential level. This paper introduces how to use union instead of cogroup (or join) in Flink to simplify task logic and improve task […]