JDBC连接MySQL

JDBCUtil类(JDBC工具类)

package Login;
import java.sql.*;     //导入java.sql包
public class JDBCUtil {//创建Login类，保证文件名与类名相同
    private static final String driver = "com.mysql.jdbc.Driver";
    private static final String url = "jdbc:mysql://cdb-4zq7z550.bj.tencentcdb.com:10078/JDBC";
    private static final String user = "xcz";
    private static final String password = "19980625xcz";
    public static Connection con = null;
    static PreparedStatement preparedStatement = null;
    static ResultSet resultSet= null;
    public static Connection getConnection() {  //建立返回值为Connection的方法
        try {        //加载数据库驱动类
            Class.forName(driver);
            System.out.println("数据库驱动加载成功");
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
        try {
            //连接腾讯云MySQL
            con = DriverManager.getConnection(url, user, password);//通过访问数据库的URL获取数据库连接对象
            System.out.println("数据库连接成功");
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return con;//按方法要求返回一个Connection对象
    }
    public static void close(Connection connection, Statement statement,ResultSet resultSet) {
        if(resultSet != null) {
            try {
                resultSet.close();
                System.out.println("resultSet.close()");
                } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if(statement != null) {
            try {
                statement.close();
                System.out.println("statement.close()");
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if(connection != null) {
            try {
                connection.close();
                System.out.println("connection.close()");
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
//    public static void main(String[] args) {

//        getConnection();

//    }

}

# 调用JDBC工具类

package numble;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.Random;
public class Test {
    public static void main(String[] args) throws SQLException {
        Connection con;
        PreparedStatement preparedStatement;
        con = JDBCUtil.getConnection();//此处调用JDBC工具类
        int count=0;
        for (int i = 1; i <= 1000; i++) {
            preparedStatement = con.prepareStatement("insert into aaa(a,b) values(?,?)");
            Random random = new Random();
            int x = random.nextInt(500)+1000;
            preparedStatement.setInt(1, i);
            preparedStatement.setInt(2, x);
            preparedStatement.executeUpdate();
            count++;
        }
        con.close();
        System.out.println(count+"条数据被插入");
    }
}

 

 

public int execUpdate(String sql) {
       private Statement statm;
       int rtn=0;
       String name="xcz";
       Connect con;
        try {
              /*String sql="select* from stu where name=?";
              PreparedStatement pstmt=con.prepareStatement(sql);
              pstmt.setString(1,name);
              rtn=pstmt.executeQuery();*/
              Statement statem=con.createStatement();
              rtn=statm.executeUpdate(sql);
             System.out.println("表中有"+ss+"行被修改");
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return rtn;
    }

 

　　

 

 statm=db.conn.createStatement();