package com.tarena.dao;
import java.util.List;
import com.tarena.entity.Product;
public interface ProductDAO {
public List<Product> queryAllProducts();
public Product queryProductByProductNo(int productNo);
}
package com.tarena.dao;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;
import com.tarena.entity.Product;
import com.tarena.util.ConnectionUtil;
public class ProductDAOImpl implements ProductDAO {
public List<Product> queryAllProducts() {
Connection conn =null;
PreparedStatement pstmt = null;
ResultSet rs = null;
List<Product> products = new ArrayList<Product>();
try{
conn = ConnectionUtil.getConnection();
String sql = "select product_no,product_name,product_price from t_product";
pstmt = conn.prepareStatement(sql);
rs = pstmt.executeQuery();
while(rs.next()){
Product product = new Product();
product.setProductNo(rs.getInt(1));
product.setProductName(rs.getString(2));
product.setProductPrice(rs.getInt(3));
products.add(product);
}
return products;
}catch(Exception e){
e.printStackTrace();
return null;
}
}
public Product queryProductByProductNo(int productNo) {
Connection conn =null;
PreparedStatement pstmt = null;
ResultSet rs = null;
Product product = null;
try{
conn = ConnectionUtil.getConnection();
String sql = "select product_no,product_name,product_price from t_product where product_no=?";
pstmt = conn.prepareStatement(sql);
pstmt.setInt(1, productNo);
rs = pstmt.executeQuery();
if(rs.next()){
product = new Product();
product.setProductNo(rs.getInt(1));
product.setProductName(rs.getString(2));
product.setProductPrice(rs.getInt(3));
}
return product;
}catch(Exception e){
e.printStackTrace();
return null;
}
}
}