解决MySQL在连接时警告：WARN: Establishing SSL connection without server's identity verificatio

起因：

程序在启动时，连接MySQL数据库，发出警告️：

Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.

例如：

import java.sql.*;
public class JdbcCreateTable {
public static void main(String args[]){
    try{
        Class.forName("com.mysql.jdbc.Driver");
    }catch(ClassNotFoundException e){
        e.printStackTrace();
    }
    try{
        Connection con=DriverManager.getConnection("jdbc:mysql://localhost:3306/test","root","root");
        Statement st=con.createStatement();
        int i=st.executeUpdate("create table Author(AID int primary key,Aname varchar(20),AContact no int,ACountry string)");
        System.out.println("Table is created"+i);
        con.close();
    }catch(SQLException e){
        e.printStackTrace();
    }
  }
}

解决：

Put the useSSL=false at the end of the name database:

import java.sql.*;
public class JdbcCreateTable {
public static void main(String args[]){
    try{
        Class.forName("com.mysql.jdbc.Driver");
    }catch(ClassNotFoundException e){
        e.printStackTrace();
    }
    try{
        // 修改了这里
        Connection con=DriverManager.getConnection("jdbc:mysql://localhost:3306/test?useSSL=false","root","root");
        Statement st=con.createStatement();
        int i=st.executeUpdate("create table Author(AID int primary key,Aname varchar(20),AContact no int,ACountry string)");
        System.out.println("Table is created"+i);
        con.close();
    }catch(SQLException e){
        e.printStackTrace();
    }
  }
}