java连接数据库，执行增删改查操作

public class ConnectionDataBaseTest {

    public static final String driver="com.mysql.jdbc.Driver";//驱动
    public static final String url="jdbc:mysql://localhost:3306/ssm";//指向数据库名
    public static final String user="root";//用户
    public static final String password="root";//密码

    public static void main(String[]args){
        try {
            Class.forName(driver);//加载驱动
            Connection connection=DriverManager.getConnection(url,user,password);//创建连接
            queryDataBase(connection);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e){
            e.printStackTrace();
        }
    }

    //查询数据
    public static void queryDataBase(Connection connection){
        try {
            String sql="SELECT * FROM user";
            Statement statement=connection.createStatement();
            ResultSet resultSet=statement.executeQuery(sql);

            int id;
            String name=null;
            int age;
            String gender=null;
            while (resultSet.next()){
                id=resultSet.getInt("id");
                name=resultSet.getString("name");
                age=resultSet.getInt("age");
                gender=resultSet.getString("gender");
                System.out.println("id:"+id+";name:"+name+";age:"+age+";gender:"+gender);
            }
            statement.close();
            resultSet.close();
        } catch (SQLException e){
            e.printStackTrace();
        }finally {
            System.out.println("数据查询成功!");
        }
    }

    //插入数据
    public static void insertDataBase(Connection connection){
        try {
            PreparedStatement preparedStatement=
                    connection.prepareStatement("INSERT INTO user(id,name,age,gender) VALUES (?,?,?,?)");
            preparedStatement.setInt(1,4);
            preparedStatement.setString(2,"马云");
            preparedStatement.setInt(3,30);
            preparedStatement.setString(4,"男");
            preparedStatement.executeUpdate();//插入，修改和删除数据时都要用excuteUpdate()
            preparedStatement.close();
        } catch (SQLException e){
            e.printStackTrace();
        }
    }

    //修改数据
    public  static void updateDataBase(Connection connection){
        try {
            PreparedStatement preparedStatement=connection.prepareStatement("UPDATE user SET name=? WHERE id=?");
            preparedStatement.setString(1,"马化腾");
            preparedStatement.setInt(2,3);
            preparedStatement.executeUpdate();
            preparedStatement.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    //删除数据
    public static void deleteDataBase(Connection connection){
        try {
            PreparedStatement preparedStatement=connection.prepareStatement("DELETE FROM user WHERE id=?");
            preparedStatement.setInt(1,2);
            preparedStatement.executeUpdate();
            preparedStatement.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}