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2.1 POI overview Official website: http://poi.apache.org/ Can analyze word, ppt, excel Application of POI 1. Export data: backup the data in the database 2. Import data: batch import data from excel into database POI support based on maven coordinate import <!-- excel2003 Package used --> <dependency> <groupId ...

I'm a zebra What to do and what to solve in this blog What knowledge is needed to solve this problem Specific code, effect In actual development, in order to avoid unnecessary null pointer exception. It is necessary to judge whether it is empty. If a method is called to judge whether it is null every time an object's prop ...

Today, let's record how to use JWT to implement user login verification. The effect of the implementation is that a token will be returned to the client for subsequent login verification. After login, the client needs to put the token in the requested head, otherwise the returned login fails. Don't talk much and go straight to ...

1. Add dependent package <?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> ...

spring boot uses logback by default. I've seen many places saying that logback consumes more performance than log4j. I haven't tried it, but I still use log4j more personally.   Look at pom dependency first <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter ...

demand Export online / offline user information of each xmpp machine room to Excel table (timed task + web button), and provide download button on Web page for download. Effect preview Export file effects Click download pop-up effect Code results overview ...

1. Kafka installation and configuration 1.1 download Kafka Download Kafka, kafka_2.11-2.1.1.tgz on the official website. 1.2 decompression Extract to the specified directory. tar -zxvf -C your directory 1.3 start kafka Switch to the installation path of kafka and start zookeeper bin/zookeeper-server-start.sh config/z ...

adopt LAMP Platform Deployment and Application The LAMP platform can already be deployed to meet client requests, but since these components are installed on one server, problems can paralyze the LAMP platform.In practice, it is not possible to deploy all LAMP platforms on the same server, which requires the use of LAMP dynamic and static sepa ...

1 public abstract class PoolEntry<T, C> { 2 3 private final String id; 4 private final T route;　　//Route 5 private final C conn;　　//http connection 6 private final long created;　　//Creation time 7 private final long validityDeadline; 8 9 private long updated; 10 11 private long exp ...

order This paper mainly studies the pullInterval of rocketmq pullInterval rocketmq-client-4.5.2-sources.jar!/org/apache/rocketmq/client/consumer/DefaultMQPushConsumer.java public class DefaultMQPushConsumer extends ClientConfig implements MQPushConsumer { private final InternalLogger log = ClientLogger.getLog(); //...... /** ...