C.a.druid.pool.druidabstractdatasource: discard long time none received connection

Make a simple record~

Many posts on the Internet say that there are about two ways to solve it:

1. Class file configuration, add configuration (invalid here)

    @PostConstruct
    public void init(){
        // discard long time none received connection
        System.setProperty("druid.mysql.usePingMethod", "false");
    }

2. The MySQL version has been adjusted accordingly (it is also invalid for me)

3. Add: – dduid.Mysql.Usepingmethod = false (valid) in the operation parameters

nohup java -Ddruid.mysql.usePingMethod=false -jar user-0.0.1-SNAPSHOT.jar --server.port=9092  >user.out &