java中创建jdbc应用程序

maven管理依赖

1.pom.xml依赖项

    <dependencies>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.32</version>
        </dependency>
    </dependencies>

2. Main.java

package cn.mayanan;

import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.DriverManager;
import java.sql.ResultSet;

public class Main {
    // JDBC驱动程序名称和数据库URL
    static final String JDBC_DRIVER = "com.mysql.cj.jdbc.Driver";
    static final String DB_URL = "jdbc:mysql://localhost:3306/demo05";

    // 数据库的凭据
    static final String USER = "root";
    static final String PASS = "123456";

    public static void main(String[] args) {
        Connection conn = null;
        Statement stmt = null;

        try {
            // 注册JDBC驱动程序
            // Class.forName("com.mysql.cj.jdbc.Driver");

            // 建立链接
            System.out.println("连接数据库...");
            conn = DriverManager.getConnection(DB_URL, USER, PASS);

            // 执行查询
            System.out.println("实例化Statement对象...");
            stmt = conn.createStatement();
            String sql;
            sql = "SELECT id, first, last, age FROM employees";
            ResultSet rs = stmt.executeQuery(sql);

            // 从结果集中提取数据
            while (rs.next()) {
                // 通过字段检索
                int id = rs.getInt("id");
                int age = rs.getInt("age");
                String first = rs.getString("first");
                String last = rs.getString("last");

                // 显示结果
                System.out.print("ID: " + id);
                System.out.print(", Age: " + age);
                System.out.print(", First: " + first);
                System.out.println(", Last: " + last);
            }

            // 清理环境
            rs.close();
            stmt.close();
            conn.close();

        } catch (SQLException e) {
            throw new RuntimeException(e);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (stmt != null) {
                    stmt.close();
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }
            try {
                if (conn != null) {
                    conn.close();
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

        System.out.println("GoodBye!");
    }
}