categoryservice.java

使用jsp+Servlet,采用MVC模式,实现了一典型小型电子商务网站的全过程.包括前台和后台的全部功能.适合于初学者学习使用.

/**
 * 
 */
package com.eshop.service;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import com.eshop.util.DBManager;
import com.eshop.vo.Category;


/**
 * 商品类别业务处理
 * @author jonson
 *
 */
public class CategoryService {
	Connection con;//数据库连接
	String selectAllCategory="select * from category";
	String selectCategoryById="select * from category where catid=?";

	/**
	 * 根据ID查找商品类别信息
	 */
	public Category getCategoryById(String id){
		Category category=null;
		DBManager dbManager= new DBManager();
		Connection conn=dbManager.GetConnection();
		try
		{
			PreparedStatement pstmt=conn.prepareStatement(selectCategoryById);
			pstmt.setString(1,id);
			ResultSet rs=pstmt.executeQuery();
          
			while(rs.next())
			{
				category=new Category();
				category.setCatid(rs.getString("catid"));
				category.setName(rs.getString("name"));
				category.setDescn(rs.getString("descn"));
			}
				conn.close();
		}
		catch(SQLException e)
		{
			e.printStackTrace();
		}
		return category;
		
	}
	
	/**
	 * 获得所有商品类别列表
	 * @return list
	 */
	public List getAllCategory(){
		List list=new ArrayList();
		DBManager dbManager= new DBManager();
		Connection conn=dbManager.GetConnection();
		try {
			PreparedStatement ps=conn.prepareStatement(selectAllCategory);
			ResultSet rs=ps.executeQuery();
			while (rs.next()){
				Category category=new Category();
				category.setCatid(rs.getString("catid"));
				category.setName(rs.getString("name"));
				category.setDescn(rs.getString("descn"));
				list.add(category);
			}
			conn.close();
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return list;
	}
	/**
	 * 保存类
	 * @param category
	 * @return
	 */
	public boolean saveCategory(Category category){
		boolean success=false;
		DBManager DbManager= new DBManager();
		Connection conn=DbManager.GetConnection();
		try {
//			Statement stm=conn.createStatement();
			PreparedStatement ps=conn.prepareStatement("INSERT INTO category(catid,name,descn)values(?,?,?)");
			ps.setString(1, category.getCatid());
			ps.setString(2, category.getName());
			ps.setString(3, category.getDescn());
			ps.executeUpdate();
			ps.close();
			conn.commit();
			success=true;
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			
			e.printStackTrace();
			try{
				conn.rollback();
			}catch(SQLException ex){
				ex.printStackTrace();				
			}
		}
		return success;		
	}
	/**
	 * 修改类
	 * @param category
	 * @return
	 */
	public boolean changeCategory(Category category){
		boolean success=false;
		DBManager dbManager= new DBManager();
		Connection conn=dbManager.GetConnection();
		try {
//			Statement stm=conn.createStatement();
			PreparedStatement ps=conn.prepareStatement
			("update category set catid=?,name=?,descn=? where catid='"+category.getCatid()+"'");
			ps.setString(1, category.getCatid());
			ps.setString(2, category.getName());
			ps.setString(3, category.getDescn());
			ps.executeUpdate();
			ps.close();
			conn.commit();
			success=true;
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			
			e.printStackTrace();
			try{
				conn.rollback();
			}catch(SQLException ex){
				ex.printStackTrace();				
			}
		}
		return success;		
	}
	/**
	 * 删除类
	 * @param category
	 * @return
	 */
	public boolean deleteCategory(Category category){
		boolean success=false;
		DBManager dbManager= new DBManager();
		Connection conn=dbManager.GetConnection();
		try {
//			Statement stm=conn.createStatement();
			PreparedStatement ps=conn.prepareStatement
			("delete from category where catid='"+category.getCatid()+"'");
			ps.executeUpdate();
			ps.close();
			conn.commit();
			success=true;
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			
			e.printStackTrace();
			try{
				conn.rollback();
			}catch(SQLException ex){
				ex.printStackTrace();				
			}
		}
		return success;
		
	}
	/**
	 * 商品类别添加，进行商品ID验证
	 */
	public boolean confirmCategory(String catid){
		boolean success=false;
		DBManager dbManager=new DBManager();
		Connection conn=dbManager.GetConnection();
		try {
			PreparedStatement ps=conn.prepareStatement("select * from category where catid=?");
			ps.setString(1, catid);
			ResultSet rs=ps.executeQuery();
			if(rs.next()){
				success=true;
			}
			conn.close();
						
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return success;		
}
}