Table of Contents 1.excel 2.Usage scenarios 3.Apache POI 4.easyExcel 5. Summary 1.excel Excel is divided into two versions, version 03 and version 07. The suffix of version 03 is xls, with a maximum of 65536 lines. The suffix of version 07 is xlsx, and there is no limit to the maximum number of lines. 2. […]
Tag: apache
Vulnerability Analysis | Apache ActiveMQ RCE Vulnerability Reproduction (CNVD-2023-69477)
1. Vulnerability description ActiveMQ is an open source message broker and integrated mode server that supports the Java Message Service (JMS) API. It is a project under the Apache Software Foundation and is used to implement message middleware to help communication between different applications or systems. There is a remote code execution vulnerability in Apache […]
[Apache Flink] Basic use of Flink DataStream API
Basic use of Flink DataStream API Article directory Preface 1. Basic usage 2. Core sample code 3. Complete the project code pom.xml WordCountExample Test verification 4. Stream execution environment 5. Reference documentation Foreword The Flink DataStream API is mainly used to handle unbounded and bounded data streams. Unbounded data flow is a data source that […]
[Apache Flink] Various application scenarios of streaming analysis
Article directory 0. Preface 1. Evolution of data processing architecture 2. Traditional data processing architecture 3. Transaction processing 4. Analytical processing Traditional data warehouse architecture for data analysis Stateful stream processing 5. Event-driven applications What is an event-driven application? 6. Data pipeline What is a data pipeline? How does Flink support data pipeline applications? Typical […]
[Apache Flink] Implementing stateful functions
Article directory Declare key-value partitioning status in RuntimeContext Implement the operator list status through the ListCheckPonitend interface Using the CheckpointedFunction interface Receive checkpoint completion notification Reference documentation Declare key-value partition status in RuntimeContext Flink provides several different primitives (data types) for keyed state. This is because different algorithms and operations may need to manage different […]
[Apache Flink] Operator based on time and window – configure time characteristics
Article directory Preface Configuration time characteristics Set time properties to event time timestamp allocator periodic water level distributor Create a class that implements the AssignerWithPeriodicWatermarks interface in order to generate watermarks periodically Fixed point water level distributor Example Reference documentation Foreword Apache Flink provides multiple types of time and window concepts, allowing users to perform […]
Django+Vue+Mysql+Apache deployment project
1.Django installation and settings: 1.1 Install Django pip install Django==4.1 -i https://pypi.douban.com/simple 1.2 Create Django project django-admin startproject web 1.3 Creating applications python manage.py startapp user 1.4 Add the application to the project in the settings under the project path INSTALLED_APPS = [ ‘django.contrib.admin’, ‘django.contrib.auth’, ‘django.contrib.contenttypes’, ‘django.contrib.sessions’, ‘django.contrib.messages’, ‘django.contrib.staticfiles’, ‘corsheaders’, ‘user’, ] 1.5 Create a […]
Galaxy Kirin System (ARM) Apache Doris cluster construction
Apache Doris needs to be deployed on the Xinchuang platform (Kunpeng ARM CPU and Galaxy Kirin V10 operating system) to store log data, use the ARM installation package compiled by the community, and configure the ARM version of JDK. The Doris community itself has very complete documentation, and the entire deployment process is conducted under […]
Solve the problem that mybatisplus reported org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.excep
Solution to mybatisplus reporting org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.exceptions.PersistenceException: Article directory Solve the problem that mybatisplus reported org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.exceptions.PersistenceException: Scenes: Exception details: Solution analyze 1. View logs 2. View the source code Summarize use mybatisplus LambdaQueryChainWrapper reported an error Scene: RegionPO one = new LambdaQueryChainWrapper<>(regionDAO) .select(RegionPO::getRegionId) .eq(RegionPO::getName, “Guangdong Province”) .one(); Exception details: […]
Use Docker to deploy Apache Superset and achieve remote access over the public network
Big data visual BI analysis tool Apache Superset enables remote access over the public network Article directory Big data visual BI analysis tool Apache Superset enables remote access over the public network Preface 1. Deploy Apache Superset using Docker 1.1 The first step is to install docker and docker compose 1.2 Clone the superset code […]