?About the author: A Matlab simulation developer who loves scientific research. He cultivates his mind and improves his technology simultaneously. For code acquisition, paper reproduction and scientific research simulation cooperation, please send a private message. Personal homepage: Matlab Research Studio Personal credo: Investigate things to gain knowledge. For more Matlab complete code and simulation customization […]
Tag: transient
[Physics Application] Implementation of transient convection and diffusion based on FVM with matlab code
?About the author: A Matlab simulation developer who loves scientific research. He cultivates his mind and improves his technology simultaneously. For cooperation on MATLAB projects, please send a private message. Personal homepage: Matlab Research Studio Personal credo: Investigate things to gain knowledge. For more Matlab complete code and simulation customization content, click Intelligent optimization algorithm […]
MySQLNonTransientConnectionException: Could not create connection to database server.
Problem description The SPringBoot project has been discontinued using MYSQL 5.7.43. The Java JDBC driver dependency selection is <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.47</version> </dependency> The driver parameter configuration is as follows: spring: datasource: username: root password: root url: jdbc:mysql://127.0.0.1:3306/data_backend?autoReconnect=true & amp;useUnicode=true & amp;characterEncoding=utf8 & amp;serverTimezone=GMT+8 driver-class-name: com.mysql.jdbc.Driver When using the backend interface testing tool to test whether […]
Instructions for using transient keyword
In Java, the transient keyword is used to indicate that a field does not need to be serialized. For example, some sensitive information (mobile phone number, password, etc.) does not need to be serialized. It should be noted that the transient keyword can only modify variables, not methods or classes. Class variables (static variables, modified […]
[Serialization] implements Serializable, ObjectOutputStream, serialVersionUID, transient
[2023, learn something new Java-25] How to solve errors in floating-point calculations: strictfp | How to protect sensitive information and improve program reliability and security: transient | Attachment: Introduction to Java Exception Handling Keywords
Review: [2023, learn something new Java-24] abstract modified classes and methods | synchronized synchronization lock | volatile modified member variables | how to ensure the visibility of variables in multithreading? | How to ensure thread safety? [2023, learn something new Java-23] A preliminary understanding of modifiers in Java: static and its functions, native features, final […]
TransientStorePool off-heap buffer pool technology
In what scenarios should TransientStorePool be turned on (technology emerges to solve problems) In RocketMQ, TransientStorePool is a mechanism to optimize disk I/O performance. It improves write performance by pre-allocating memory blocks, writing messages to pre-allocated memory blocks (direct memory), and then using memory-mapped files (Memory-Mapped File) to flush data in memory blocks to disk. […]
java.sql.SQLNonTransientConnectionException: Could not create connection to database server. Attempt
When doing springboot + flowable bpm, the following error is reported 2023-03-24 08:57:43.564 ERROR 79604 — [ main] com.zaxxer.hikari.pool.HikariPool : HikariPool-1 – Exception during pool initialization. java.sql.SQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 3 times. Giving up. at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:110) ~[mysql-connector-java-8.0.23.jar:8.0.23] at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:97) ~[mysql-connector-java-8.0.23.jar:8.0.23] at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:89) ~[mysql-connector-java-8.0.23.jar:8.0.23] at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:63) ~[mysql-connector-java-8.0.23.jar:8.0.23] at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:73) ~[mysql-connector-java-8.0.23.jar:8.0.23] […]
Error resolution of “com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException” when connecting to mysql
Connect to mysql to report “com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException” error solution Database connection failed, solve it ** Full error ** Serious: Servlet.service() for servlet [com.iheima.web.LoginServlet] in context with path [/request-demo] threw exception org.apache.ibatis.exceptions.PersistenceException: ### Error querying database. Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server. ### The error may exist in com/iheima/mapper/UserMapper.java (best guess) ### The error […]
[Solved] com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException exception solution
The reason is that I imported the webapps project “woniusales.war” in tomcat, started tomcat by double-clicking startup.bat, and reported an error in the black box. Open localhost:8080/woniusales and find that the project was not successfully configured. [Severe] com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException The reason for the error is: the mysql version on the computer is high, and the mysql-java […]