Programmer Group

Previous bug resolution bug1 Previously, when setting the upload report, a field was missing to store the package id, because a member can reserve multiple packages. Now the problem has been solved Solution: in t_ In the report table (that is, in the database where the file name of the report is stored), a setmealId field is added to store t ...

preface 1. How to analyze the method of high CPU utilization of JVM. 2. How to troubleshoot online jvm memory leaks. 3. How to locate the jvm thread deadlock problem. 4. How to solve the problem of jvm frequently full gc, etc. These problems will be solved step by step through this article. 1, Pre preparation 1. First prepare a web s ...

What is TCC? TCC is the abbreviation of Try, Confirm and Cancel. It was first proposed by a paper entitled Life beyond Distributed Transactions:an Apostate's Opinion published by Pat Helland in 2007. TCC composition TCC is divided into three stages Try phase: try to execute, complete all business checks (consistency), and reserve necessary b ...

Comparison class introduce Under normal circumstances, objects in Java can only be compared: = = or! =, Comparison of > or < is not possible. However, in the development scenario, we need to sort multiple objects, that is, we need to compare the size of objects. How to implement: you need either of the two interfaces: Comparable or Co ...

Absrtact: it is inevitable to record sensitive operations in business systems, which can be realized by hard coding or simple annotation, but they are not elegant enough. Today, I share a log tool written by myself. This is a logging tool implemented with reference to an article by meituan. It can record operation logs flexibly and has good ...

SpringMVC 1, Introduction to spring MVC 1. What is spring MVC? The framework Spring MVC framework developed on the basis of Spring is the controller framework C-layer framework (struts 2 is also the C-layer framework) Essence: replace the struts 2 framework as a controller In order to enable Spring to plug into MVC architecture, Spring fra ...

User login 1 user login persistence layer Learning video address [actual combat full version of SpringBoot project] actual combat of SpringBoot+MyBatis+MySQL computer mall project_ Beep beep beep_ bilibili 1.1 planning SQL statements to be executed The SQL statement to be executed by the user login function is to query the user data accordi ...

1, Introduction to libSVM libSVM is a set of support vector machine library developed by Professor Chih Jen Lin of Taiwan in 2001. This library has fast operation speed and can easily classify or regress data. libSVM has become the most widely used SVM Library in China because of its small program, flexible application, few input parameter ...

Pay attention to the versions of different software you use. It's best to match them. If they don't match, I haven't tried, and there may be errors The memory of a single machine should be more than 2G, and 3G is the best. It should be for all the memory consumption compared on one machine. The memory service can not be started if it ...

Foreword: in the last article, we learned the sequence table and found that we have a certain grasp of the concept of the sequence table, but after learning the sequence table, we found that there are some places that we can't do better or difficult to do, so we have a linked list. This article will take you into the study of the linked list! ...