在Linux下?使用java?訪問數據庫 ，

java 1.7版本，

mysql 8.0.33版本，

連接驅動???mysql-connector-java-5.1.49.jar

代碼如下：

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;public class J {public static void main(String[] args) throws Exception{//1.導入jar包//2.注冊驅動Class.forName("com.mysql.jdbc.Driver");// Class.forName("com.mysql.cj.jdbc.Driver");//3.獲取連接Connection con = DriverManager.getConnection("jdbc:mysql://mysql.sqlpub.com:3306/huangjin","abc這里變了","fc12f7a5215e8e0a");//4.獲取執行者對象Statement stat = con.createStatement();//5.執行sql語句，并且接收結果String sql = "SELECT * FROM user";ResultSet rs = stat.executeQuery(sql);//6.處理結果while(rs.next()) {System.err.println("\033[32m " + rs.getInt("uid") + "\t" + rs.getString("loginname")+ "\033[0m");}//7.釋放資源con.close();stat.close();con.close();}
}

此時? java源碼，與連接的jar包在一個目錄下

[root@localhost src]# javac -cp mysql-connector-java-5.1.49.jar J.java
[root@localhost src]# java -cp ./mysql-connector-java-5.1.49.jar:. J
?

Fri Aug 11 19:46:57 CST 2023 WARN: 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.
?11111111 ? ? ? zhangsan

試驗二

#查看linux系統

root@dcs-dd2b5627-0:/workspace/Java/src# cat /etc/os-release
PRETTY_NAME="Debian GNU/Linux 11 (bullseye)"
NAME="Debian GNU/Linux"
VERSION_ID="11"
VERSION="11 (bullseye)"
VERSION_CODENAME=bullseye
ID=debian
HOME_URL="https://www.debian.org/"
SUPPORT_URL="https://www.debian.org/support"
BUG_REPORT_URL="https://bugs.debian.org/"
root@dcs-dd2b5627-0:/workspace/Java/src#?

java 1.8版本，

mysql 8.0.33版本，

連接驅動???mysql-connector-j-8.0.33.jar

[root@localhost src]# javac -cp mysql-connector-j-8.0.33.jar J.java
[root@localhost src]# java -cp ./mysql-connector-j-8.0.33.jar:. J