包装类insert到数据库表空字段报空指针异常

Question

pojo 里面对应表的属性为Integer，数据库表字段某一字段指定可以为空，不给该属性赋值，当用insert语句添加数据进入该表时，报空指针异常，是为什么？

Servlet给该对象设值：
Productorderitem productorderitem = new Productorderitem();
productorderitem.setProductorderitemNumber(Integer.parseInt(product_number));
productorderitem.setProductorderitemSize(ProductSizeUtil.getSizeByString(product_size));
productorderitem.setProductorderitemPrice(product.getProductPrice());
productorderitem.setProductorderitemProductId(Integer.parseInt(productId));

dao层实现类的方法代码：
public boolean insertProductorderItem(Productorderitem productorderitem, Connection conn) throws Exception {
String sql = "insert into productorderitem(productorderitem_number,productorderitem_size,productorderitem_price,productorderitem_product_id,productorderitem_order_id,productorderitem_user_id,productorderitem_userMessage) values(七个?)";
PreparedStatement ps = conn.prepareStatement(sql);
ps.setInt(1, productorderitem.getProductorderitemNumber());
ps.setInt(2, productorderitem.getProductorderitemSize());
ps.setDouble(3, productorderitem.getProductorderitemPrice());
ps.setInt(4, productorderitem.getProductorderitemProductId());
ps.setInt(5, productorderitem.getProductorderitemOrderId());
ps.setInt(6, productorderitem.getProductorderitemUserId());
ps.setString(7, productorderitem.getProductorderitemUserMessage());
int row = ps.executeUpdate();
if(row>0){
return true;
}
DBHelper.closePreparedStatement(ps);
return false;
}

Answer 1

错误位置可以定位吗
是不是你integer类型数据赋值取值时候的问题
在赋值取值前判断一下是不是为空或者null
为空或者null时不进行赋值取值

productorderitem.setProductorderitemNumber(Integer.parseInt(product_number))

ps.setInt(1, productorderitem.getProductorderitemNumber());

https://blog.csdn.net/weixin_48240945/article/details/120323300

https://blog.csdn.net/weixin_43080383/article/details/120709831