jsp连接mysql出现乱码

-- 检查数据库字符集
SHOW CREATE DATABASE your_database_name;

-- 修改数据库字符集
ALTER DATABASE your_database_name CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;

-- 检查表字符集
SHOW CREATE TABLE your_table_name;

-- 修改表字符集
ALTER TABLE your_table_name CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>

String url = "jdbc:mysql://localhost:3306/your_database_name?useUnicode=true&characterEncoding=utf8mb4";
String user = "your_username";
String password = "your_password";

try {
    Connection conn = DriverManager.getConnection(url, user, password);
    // 其他操作
} catch (SQLException e) {
    e.printStackTrace();
}

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<%@ page import="java.sql.*" %>

<%
    String url = "jdbc:mysql://localhost:3306/your_database_name?useUnicode=true&characterEncoding=utf8mb4";
    String user = "your_username";
    String password = "your_password";

    try {
        Connection conn = DriverManager.getConnection(url, user, password);
        String sql = "SELECT * FROM your_table_name";
        Statement stmt = conn.createStatement();
        ResultSet rs = stmt.executeQuery(sql);

        while (rs.next()) {
            String data = rs.getString("your_column_name");
            out.println(data);
        }

        rs.close();
        stmt.close();
        conn.close();
    } catch (SQLException e) {
        e.printStackTrace();
    }
%>