java连接mysql数据库

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风云正 2023-03-02 07:32:06 ©著作权

文章标签 数据库 java System sql 文章分类 HarmonyOS 后端开发

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一个小例子测试java是否可以连接的上mysql数据库

import java.sql.*;

public class Jdbc {
  public static void main(String[] args) {
    Connection conn = null;
    Statement stmt = null;
    ResultSet rs = null;
    String url = null;
    String user = null;
    String password = null;
    String sql = null;
    try {
      Class.forName("com.mysql.jdbc.Driver"); // 加载mysq驱动
    } catch (ClassNotFoundException e) {
      System.out.println("驱动加载错误");
      e.printStackTrace();// 打印出错详细信息
    }
    try {
      url = "jdbc:mysql://127.0.0.1/mysql";
      user = "root";
      password = "root";
      conn = DriverManager.getConnection(url, user, password);
    } catch (SQLException e) {
      System.out.println("数据库链接错误");
      e.printStackTrace();
    }
    try {
      stmt = conn.createStatement();
      sql = "select * from user";
      rs = stmt.executeQuery(sql);// 执行sql语句
      while (rs.next()) {
        System.out.println(rs.getString("Host"));
        System.out.println(rs.getString("password"));
      }
    } catch (SQLException e) {
      System.out.println("数据操作错误");
      e.printStackTrace();
    }
    // 关闭数据库
    try {
      if (rs != null) {
        rs.close();
        rs = null;
      }
      if (stmt != null) {
        stmt.close();
        stmt = null;
      }
      if (conn != null) {
        conn.close();
        conn = null;
      }
    } catch (Exception e) {
      System.out.println("数据库关闭错误");
      e.printStackTrace();
    }
  }

}