Programmer Group

Understanding of meta path: (what I do is the text direction, so I take commentator - number of comments - commentator as a meta path) A meta path is a path where multiple (more than 2) nodes are connected through another type of node. In the yelp dataset, I want to build a meta path of comments - number of comments - comments. That is to find ...

1. Visibility between threads Multithreading improves efficiency and caches data locally, making data modification invisible, To ensure visibility, either trigger synchronization instructions or add volatile modified memory. As long as there are modifications, synchronize each thread involved immediately /** * volatile Keyword to make a var ...

Foreword: in this article, we learn the definition and use of arrays. We have learned some basic contents of Java before, and then today we will learn arrays in Java. Each picture: Let's go into the study of arrays ba! 1, Basic usage of array To understand the basic usage of arrays, first understand: what is an array? In fact, ar ...

Java source code reading notes - stream Why learn stream In Java programming, ArrayList is estimated to be one of the most commonly used classes, which is used as an array in daily life. For array operations, traversal, data filtering, data modification and other operations will be involved. The simplest of these operations is for loop traver ...

Fail fast and fail safe mechanisms of Iterator The difference between fail fast and fail safe: fail safe allows you to modify the data in the container during traversal, while fail fast does not. Fail fast Directly traverse the container. In the process of traversal, once it is found that the data in the container has been modified, ...

preface Recently, a customer of the company used PostgreSql to store data. In the export function, it was found that in the case of big data, the memory will grow until it overflows. Because the fetchSize is set for stream query in the export function, there will be no memory overflow. Then the investigation found that all the data were obtain ...

1 Introduction to easyexcel EasyExcel is an open source project of Alibaba open source, which is a simple and memory saving read-write Excel based on Java. Support reading and writing 100M excel while saving memory as much as possible. GitHub address: https://github.com/alibaba/easyexcel Official documents: https://www.yuque.com/easyexcel/do ...

1 Overview Computer network is a computer system that links multiple computers and their external devices with independent functions in different geographical locations through communication lines, and realizes resource sharing and information transmission under the management and coordination of network operating system, network managemen ...

2021SC@SDUSC Call Site analysis Groovy 1.6 introduces Call Site optimization. Call Site optimization is actually the cache of method selection. Method selection In static languages (such as Java), the binding of method calls is completed at compile time (not exactly, such as virtual functions, but in general, method calls in static langua ...

preface This chapter describes in detail the use and related operations of linked list, a linear data structure. In fact, many people can't understand the link between the nodes and the link before the nodes. It will be very difficult to learn, because I was like this at the beginning. I figured it out later. In fact, it is the following idea: ...