Login case (black horse) - simple login case using druid database connection pool, JdbcTemplate technology and Servlet

catalog User login case requirements Development steps: 1. Create project, configuration file and import jar package. 2. Write logged in login.html Page. 3. Create the database userlogin and the table user. 4. Create a package com.qgl . 'domain'. Create an entity class user. The entity class user c ...

Posted by irish21 on Sun, 28 Jun 2020 17:55:56 -0700

Deploying a hadoop cluster on Centos7

Hadoop's Trample Notes (1) Deploying a hadoop cluster on Centos7 Environmental Science Machine 1(hadoop1-ali) Ali Cloud (CentOS 7.3) 120.26.173.104 Machine 2(hadoop2-hw) Huawei Cloud (CentOS 7.4) 114.116.233.156 Where the first server serves as a namenode and the second serves as a datanode Modify hostname and hostfile Execute on two machines ...

Posted by maxxx on Sun, 28 Jun 2020 17:21:11 -0700

Why is enumeration recommended?

Enumeration is a new data type in JDK 1.5. With enumeration, we can well describe some specific business scenarios, such as spring, summer, autumn and winter in a year, Monday to Sunday in a week, and various colors, as well as some state information, such as error codes. Enumeration type not only exists in Java language, but also can be found ...

Posted by pinxxx on Sat, 27 Jun 2020 23:12:24 -0700

Chapter 1 JavaScript foundation [cloud smart link]

Chapter 1 JavaScript Basics 1. What is JavaScript? HTML+CSS completes the static page display, but to complete better and more complex user interaction and data interaction and display, you need to use JavaScript. JavaScript is an object-based and event driven scripting language with security performance 2. Features of JavaScript a. You can add ...

Posted by glitch003 on Sat, 27 Jun 2020 22:26:06 -0700

Short link service practice

Article catalog Business scenario Practice mode The first way The second way code implementation Function extension Distributed high availability other target Realize the change from ordinary website to short website reference resources:Design short URL system How are short links designed? Get ...

Posted by smarlowe on Sat, 27 Jun 2020 21:53:43 -0700

RocketMQ entry to the ground novice can also understand the principle and practice!

Learning any technology is a two-step process: Setting up the environment helloworld I'm no exception. I'll do it directly. 1, RocketMQ installation 1. Documents Official website http://rocketmq.apache.org GitHub https://github.com/apache/rocketmq 2. Download wget https://mirror.bit.edu.cn/apache/rocketmq/4.7.0/rocketmq-all-4.7.0-bin-rele ...

Posted by muretto on Sat, 27 Jun 2020 20:44:03 -0700

Playing with Stream in Java 8

Playing with Stream in Java 8 By litesky Link: http://www.jianshu.com/p/11c925cdba50 I believe you have heard about Java8 Stream, but you may not be able to use it or you are not familiar with it. This article will take you to use it from scratch, step by step, and lead you to the peak of Stream. Operator What are operators? Operator is a k ...

Posted by michibk on Sat, 27 Jun 2020 19:14:03 -0700

Ajax class notes

Ajax class notes jQuery simplifies js, mainly dom operation Find it (selector) Do it (dom operation method) selector Basic selector $("div") $("#div") $(".cls") Level selector $("div span"): a selector connected with spaces to find descendants $("div > span"): use t ...

Posted by nomanoma on Sat, 27 Jun 2020 18:55:02 -0700

362. Java intermediate 17 - [JDBC] June 27, 2020

0. Directory 1,JDBC 2. Import the jar package of MySQL JDBC for the project 3. Initialize driver 4. Establish a connection to the database 5. Create Statement 6. Execute SQL statement 7. Close connection 8. Use try with resource to automatically close the connection 9. Reference link 1,JDBC JDBC ...

Posted by han2754 on Sat, 27 Jun 2020 02:34:49 -0700

Junit unit test and reflection

1.Junit unit test Test classification: 1. Black box test: do not need to write code, do not see the process of program execution, input some parameters, and see the expected results. 2. White box test: you need to write code, you can see the process of program execution, enter some parameters, and see ...

Posted by rolwong on Sat, 27 Jun 2020 00:05:30 -0700