troubleshoot: use JFR to solve memory leaks

Introduction Although java has automatic GC, there will be memory leaks. Of course memory leaks in java are different from leaks in C++. All allocated memory objects in C++ need to be freed manually by the programmer. But this process is not needed in java, everything is done automatically by GC. So is there no memory leak in java? To answer th ...

Posted by paxman356 on Mon, 23 May 2022 11:12:28 +0300

Analysis and java implementation of search related topics in binary tree in Leetcode

Analysis and java implementation of search related topics in binary tree in Leetcode In fact, there are some miscellaneous problems in this category. It is basically to find some or a specific value in the binary tree. There are many problems. We will summarize them through two or three articles, but generally speaking, it is basically BFS, whi ...

Posted by HavokDelta6 on Mon, 23 May 2022 10:13:08 +0300

Introduction to Redis

summary https://baike.baidu.com/item/Redis/6549233?fr=aladdin Baidu Encyclopedia Basic knowledge redis has 16 databases by default, and the 0 database is used by default. You can use the * * select * * command to switch Connected. my:0>select 3 # Switch database "OK" my:3>dbsize # View DB size "0" my:3> Other commands ...

Posted by manalnor on Mon, 23 May 2022 07:29:25 +0300

RabbitMQ and data synchronization

learning target Learn about common MQ products Understand RabbitMQ's 5 message model 1. Problems with search and commodity services The original data of the commodity is stored in the database, and additions, deletions, modifications, and searches are completed in the database. The data source of the search service is the index database. If ...

Posted by andynightingale on Mon, 23 May 2022 06:25:09 +0300

Spring boot: single file upload / multiple file upload / multiple file fields upload in the form (spring boot 2.3.2)

1, How to realize the correspondence between the description and the file when there are multiple file fields in the form? 1. Description and document correspondence In the file upload page, if there are multiple file fields and multiple corresponding file descriptions, How do documents and instructions correspond? We can add the same number to ...

Posted by clodius on Mon, 23 May 2022 06:10:09 +0300

Imitating the source code of Tiktok short video system to take photos and videos based on CameraX

Background: Recently, I was working on an APP video upload project. Due to the use of my own server, there are certain memory restrictions. At present, most mobile phones have a large resolution, and the video captured is several megabytes in a few seconds. How to compress the recorded video is the same as wechat. Therefore, I consulted some ma ...

Posted by Loldongs on Mon, 23 May 2022 01:13:51 +0300

Spring Boot 2.x Basic Tutorial: Using Centralized Cache Redis

Earlier we introduced the usage of two in-process caches, including the default ones used by Spring Boot ConcurrentMap cache as well as Cache framework EhCache . Although EhCache can be applied to many application scenarios, since EhCache is an in-process caching framework, in cluster mode, the caches between each application server are indepen ...

Posted by cdrees on Mon, 23 May 2022 00:05:55 +0300

Strategic Patterns for Design Patterns

Policy Mode Behavioral patterns In Strategy Pattern, the behavior of a class or its algorithm can be changed at run time. In policy mode, we create an object representing various policies and a context object whose behavior changes as the policy object changes. The policy object changes the execution algorithm of the context object. introduce I ...

Posted by unknownsheep on Sun, 22 May 2022 23:14:27 +0300

Java thread pool Architecture Principle and source code analysis (ThreadPoolExecutor)

In the previous article on JUC, we mentioned the creation of thread pool exectors. In the article:< JUC series of java - external Tools >There are detailed descriptions in the first part of the, please refer to;   In fact, the article explains the external use mode, but does not say how the internal implementation is implemented. I ...

Posted by herschen on Sun, 22 May 2022 22:45:09 +0300

Leetcode Best Time to Buy and Sell Stock series topic analysis and java implementation

Leetcode Best Time to Buy and Sell Stock series topic analysis and java implementation The title of this series is to allow us to trade according to restrictions in a continuous period of stock prices to maximize profits. Each derivative title will set some restrictions Best Time to Buy and Sell Stock I Best Time to Buy and Sell Stock II Best ...

Posted by Karlos2394 on Sun, 22 May 2022 21:32:50 +0300