Daily training - day22

day22_0519 choice question 1: simply select the best time O(n^2) average time O(n^2) worst time O(n^2) 2: Directly insert the best time O(n) average time O(n^2) worst time O(n^2) 3: Bubble sort best time O(n) average time O(n^2) worst time O(n^2) 4: Hill sort ^ best time ^ O(n) average time O(logn) worst time ^ O(n^s) 1 < s < 2 ...

Posted by QuietWhistler on Fri, 20 May 2022 01:49:27 +0300

Java Web -- servlet (learning notes)

catalogue 1. What is a servlet? 2. Working mode of Servlet 3. What are the main types of servlets 4. Create a Servlet class and configure it to the server 4.1 create a Servlet class and inherit HttpServlet (created manually) 4.2 configuring servlet s in Tomcat (must be configured in web.xml) 4.3 automatic creation and configuration &n ...

Posted by vcarter on Fri, 20 May 2022 01:41:15 +0300

java Foundation Consolidation - the first AiYWM in the universe: in order to make a living, handwritten RPC04~Version04 (how can an object be equivalent to a pile of member variables) are set up

Version04: In version 03, if there are some other methods in my interface, do you have to pass an int type every time, such as 221? Can each method only receive integers? Can't other types? So I have to go further and shield this difference. Just like min Xiaoyan didn't want to see the details of processing the network at the beginning, how do ...

Posted by tamilmani on Fri, 20 May 2022 00:56:03 +0300

JavaSE-No.8 - Polymorphism of the Three Features of Java

JavaSE Portal JavaSE_Start JavaSE-No.7.1 - Java's inheritance (super keyword) JavaSE-No.7.2 - Java's Inheritance (and Composition) content 1. The concept of polymorphism2. The realization conditions of polymorphism rewrite 3. Up and down transitions 3.1 Upward Transformation3.2 Downcasting instanceof 4. Rewritten design rules ...

Posted by Big X on Fri, 20 May 2022 00:12:51 +0300

A complete troubleshooting record of JVM out of heap memory leakage

preface Record the troubleshooting process and ideas of an online JVM out of heap memory leak, including some JVM memory allocation mechanisms and common JVM troubleshooting instructions and tools. I hope it will be helpful to you. In the whole troubleshooting process, I have also taken many detours, but in the article, I will still write out t ...

Posted by thefisherman on Thu, 19 May 2022 23:13:51 +0300

java secure coding guide: Mutability variability

catalogue brief introduction Mutable and immutable objects Create a copy of the mutable object Create a copy method for the mutable class Don't trust equals Do not directly expose modifiable properties public static fields should be set to final public static final field should be immutable brief introduction mutable (variable) and immutab ...

Posted by faizanno1 on Thu, 19 May 2022 23:09:08 +0300

71 - advertising management module and user management module of the project

Advertising management module and user management module of the project In the last blog (Chapter 70 blog), we completed the course management module, and then we completed the advertising management module and user management module Advertising management module: Realize the following functions: Advertising space list query Add ad space ...

Posted by amrigo on Thu, 19 May 2022 22:51:48 +0300

Build a picture server based on docker container

   Recently, there is a need to store pictures in the server, so I am going to build my own picture server, based on the centos system, and install nginx for mapping. Before starting, it is recommended to update the yum source of centos # update yum source yum update Create an image   It’s time to build your own server. I don&r ...

Posted by ShaileshD on Thu, 19 May 2022 22:43:21 +0300

Arthas realizes a CPU troubleshooting and code hot update

Author he Bo [the official community of Arthas is holding an essay solicitation activity. You will get a prize if you participate~ Click Submit] 1. Preface background Online code often takes up too much CPU. According to past experience, I will use the top instruction and further use jstack to check the specific information for problem troubles ...

Posted by tech0925 on Thu, 19 May 2022 22:04:54 +0300

JAVA beginner notes

Simple understanding of the basic rules and syntax of java Learning website: Java tutorial | rookie tutorial Beginner Java Java language is a pure object-oriented programming language Java (Standard Edition) JDK,JRE,JVM JDK : Java Development Kit JRE : Java Runtime Environment JVM : JAVA Virtual Machine JDK Download https://www.oracle.com/jav ...

Posted by Eratimus on Thu, 19 May 2022 21:18:15 +0300