public class ItemsDAO {

//获得所有的商品信息

public ArrayList<Items> getAllItems(){

Connection conn = null;

PreparedStatement stmt = null;

ResultSet rs = null;

ArrayList<Items>list = new ArrayList<Items>();//商品集合

try{

conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/items","root","123456");

String sql = "select * from items where id =?;";//SOL语句

stmt = conn.prepareStatement(sql);

rs = stmt.executeQuery();

while(rs.next()){//商品初始化

Items item = new Items();

item.setId(rs.getInt("id"));

item.setName(rs.getString("name"));

item.setPress(rs.getString("press"));

item.setNumber(rs.getInt("number"));

item.setPrice(rs.getInt("price"));

item.setPicture(rs.getString("picture"));

item.setNumber(rs.getInt("number"));

list.add(item);//把一个商品加入集合

}

return list;//返回集合

}

catch(Exception ex){

ex.printStackTrace();

return null;

}finally{

//释放数据集对象

if(rs != null){

try{

rs.close();

rs = null;

}

catch(Exception ex){

ex.printStackTrace();

}

//释放语句对象

if(stmt != null){

try{

stmt.close();

stmt = null;

}

catch(Exception ex){

ex.printStackTrace();

}

}

}

}

}

我的DAO类是这样的 但是我不知道哪里不对呢 求指教

你的preparestatement没有传参数1的值，已经报出来了

看一下你后台DAO类写的语句对不对