测试tomcat连接mysql数据库

<Context>
    <Resource name="jdbc/TestDB"
              auth="Container"
              type="javax.sql.DataSource"
              maxTotal="100"
              maxIdle="30"
              maxWaitMillis="10000"
              username="your_username"
              password="your_password"
              driverClassName="com.mysql.cj.jdbc.Driver"
              url="jdbc:mysql://localhost:3306/your_database?useSSL=false&serverTimezone=UTC"/>
</Context>

<resource-ref>
    <description>DB Connection</description>
    <res-ref-name>jdbc/TestDB</res-ref-name>
    <res-type>javax.sql.DataSource</res-type>
    <res-auth>Container</res-auth>
</resource-ref>

import java.io.IOException;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.sql.DataSource;

@WebServlet("/testdb")
public class TestDBServlet extends HttpServlet {
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        try {
            Context initContext = new InitialContext();
            Context envContext = (Context) initContext.lookup("java:/comp/env");
            DataSource ds = (DataSource) envContext.lookup("jdbc/TestDB");
            Connection conn = ds.getConnection();
            Statement stmt = conn.createStatement();
            ResultSet rs = stmt.executeQuery("SELECT * FROM your_table");
            
            while (rs.next()) {
                // Process the result set
            }
            
            rs.close();
            stmt.close();
            conn.close();
        } catch (NamingException | SQLException e) {
            e.printStackTrace();
            response.getWriter().write("Database connection failed: " + e.getMessage());
        }
    }
}

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.23</version>
</dependency>