显示新闻展示、增加、删除功能
新闻展示
welcome.jsp页面中展示新闻列表(部分代码)
<!-- 商品列表展示 -->
<table>
<tr>
<td>商品编号</td><td>商品名称</td><td>商品产地</td><td>商品类型</td><td>商品进价</td><td>商品售价</td><td>商品库存</td><td>编辑|删除</td>
</tr>
<%
// 获取商品列表（类型强转）
List<Commodity> cList = (List<Commodity>)session.getAttribute("cList");
if(cList != null && cList.size() > 0){
for(Commodity c:cList){
%>
<tr>
<td><%=c.getC_id() %></td><td><%=c.getC_name() %></td><td><%=c.getC_madein() %></td><td><%=c.getCt().getCt_name() %></td><td><%=c.getC_inprice() %></td><td><%=c.getC_outprice() %></td><td><%=c.getC_num() %></td><td>编辑|删除</td>
</tr>
<%
}
}
%>
</table>
commoditytypeDao接口的抽象方法，根据商品种类编号，返回商品种类类型，供商品表使用
public interface CommoditytypeDao {
Commoditytype getCommoditytypeById(String ct_id);
}
commoditytypeDaoImpl实现类，实现接口方法
@Override
public Commoditytype getCommoditytypeById(String ct_id) {
Commoditytype ct = null;
try {
Connection conn = DBHelper.getConnection();
String sql = "select * from commoditytype where ct_id=?";
List param = new ArrayList();
param.add(ct_id);
ResultSet rs = DBHelper.executeQuery(conn, sql, param);
rs.next();
ct = new Commoditytype(rs.getString("ct_id"),rs.getString("ct_name"));
DBHelper.closeConnection(conn);
}catch(Exception e) {
e.printStackTrace();
}
return ct;
}
CommoditytypeController控制层传递信息
public class CommoditytypeController {
private CommoditytypeDao commoditytypeDao = null;
public CommoditytypeController() {
commoditytypeDao = new CommoditytypeDaoImpl();
}
}
CommodityDao接口中，添加方法，返回商品表所有信息的集合
public interface CommodityDao {
List<Commodity> getCommodityList();
}
CommodityDaoImpl实现类实现接口的方法
@Override
public List<Commodity> getCommodityList() {
List<Commodity> commoditys = new ArrayList<Commodity>();
try {
Connection conn = DBHelper.getConnection();
String sql = "select * from commodity";
ResultSet rs = DBHelper.executeQuery(conn, sql, null);
while(rs.next()) {
Commodity c = new Commodity();
c.setC_id(rs.getString("c_id"));
c.setC_name(rs.getString("c_name"));
c.setC_madein(rs.getString("c_madein"));
c.setC_type(rs.getString("c_type"));
c.setC_inprice(rs.getInt("c_inprice"));
c.setC_outprice(rs.getInt("c_outprice"));
c.setC_num(rs.getInt("c_num"));
c.setCt(new CommoditytypeDaoImpl().getCommoditytypeById(rs.getString("c_type")));
commoditys.add(c);
}
DBHelper.closeConnection(conn);
}catch(Exception e) {
e.printStackTrace();
}
return commoditys;
}
CommodityController控制层
public class CommodityController {
private CommodityDao commodityDao = null;
public CommodityController() {
commodityDao = new CommodityDaoImpl();
}
public List<Commodity> getCommodityList() {
return commodityDao.getCommodityList();
}
}
在LoginServlet中用session保存，在welcome中读取并显示
List<Commodity> cList = new CommodityController().getCommodityList();
session.setAttribute("cList", cList);
增加、删除功能
CommoditytypeDao接口
public interface CommoditytypeDao {
Commoditytype getCommoditytypeById(String ct_id);
// 用于下拉列表读取商品类型名称
List<Commoditytype> getCommoditytypeList();
}
CommoditytypeDaoImpl实现类
public class CommoditytypeDaoImpl implements CommoditytypeDao{
@Override
public Commoditytype getCommoditytypeById(String ct_id) {
Commoditytype ct = null;
try {
Connection conn = DBHelper.getConnection();
String sql = "select * from commoditytype where ct_id=?";
List param = new ArrayList();
param.add(ct_id);
ResultSet rs = DBHelper.executeQuery(conn, sql, param);
rs.next();
ct = new Commoditytype(rs.getString("ct_id"),rs.getString("ct_name"));
DBHelper.closeConnection(conn);
}catch(Exception e) {
e.printStackTrace();
}
return ct;
}
@Override
public List<Commoditytype> getCommoditytypeList() {
List<Commoditytype> cts = new ArrayList<>();
try {
Connection conn = DBHelper.getConnection();
String sql = "select * from commoditytype";
ResultSet rs = DBHelper.executeQuery(conn, sql, null);
while(rs.next()) {
Commoditytype ct = new Commoditytype(rs.getString("ct_id"),rs.getString("ct_name"));
cts.add(ct);
}
DBHelper.closeConnection(conn);
}catch(Exception e) {
e.printStackTrace();
}
return cts;
}
}
CommoditytypeController 控制层
public class CommoditytypeController {
private CommoditytypeDao commoditytypeDao = null;
public CommoditytypeController() {
commoditytypeDao = new CommoditytypeDaoImpl();
}
public List<Commoditytype> getCommoditytypeList(){
return commoditytypeDao.getCommoditytypeList();
}
}
CommodityDao 接口
public interface CommodityDao {
List<Commodity> getCommodityList();
int istCommodity(Commodity c);
int delCommodityById(String c_id);
}
CommodityDaoImpl实现类
public class CommodityDaoImpl implements CommodityDao {
@Override
public List<Commodity> getCommodityList() {
List<Commodity> commoditys = new ArrayList<Commodity>();
try {
Connection conn = DBHelper.getConnection();
String sql = "select * from commodity";
ResultSet rs = DBHelper.executeQuery(conn, sql, null);
while(rs.next()) {
Commodity c = new Commodity();
c.setC_id(rs.getString("c_id"));
c.setC_name(rs.getString("c_name"));
c.setC_madein(rs.getString("c_madein"));
c.setC_type(rs.getString("c_type"));
c.setC_inprice(rs.getInt("c_inprice"));
c.setC_outprice(rs.getInt("c_outprice"));
c.setC_num(rs.getInt("c_num"));
c.setCt(new CommoditytypeDaoImpl().getCommoditytypeById(rs.getString("c_type")));
commoditys.add(c);
}
DBHelper.closeConnection(conn);
}catch(Exception e) {
e.printStackTrace();
}
return commoditys;
}
@Override
public int istCommodity(Commodity c) {
int line = 0;
try {
Connection conn = DBHelper.getConnection();
String sql = "insert into commodity(c_id,c_name,c_madein,c_type,c_inprice,c_outprice,c_num) values (?,?,?,?,?,?,?)";
List param = new ArrayList();
param.add(c.getC_id());
param.add(c.getC_name());
param.add(c.getC_madein());
param.add(c.getC_type());
param.add(c.getC_inprice());
param.add(c.getC_outprice());
param.add(c.getC_num());
line = DBHelper.executeUpdate(conn, sql, param);
DBHelper.closeConnection(conn);
}catch(Exception e) {
e.printStackTrace();
}
return line;
}
@Override
public int delCommodityById(String c_id) {
int line = 0;
Connection conn = DBHelper.getConnection();
String sql = "delete from commodity where c_id=?";
List param = new ArrayList();
param.add(c_id);
line = DBHelper.executeUpdate(conn, sql, param);
DBHelper.closeConnection(conn);
return line;
}
}
CommodityController 控制层
public class CommodityController {
private CommodityDao commodityDao = null;
public CommodityController() {
commodityDao = new CommodityDaoImpl();
}
public List<Commodity> getCommodityList() {
return commodityDao.getCommodityList();
}
public int istCommodity(String c_name,String c_madein,String c_type,Integer c_inprice,Integer c_outprice,Integer c_num) {
Commodity c = new Commodity(System.currentTimeMillis()+"",c_name,c_madein,c_type,c_inprice,c_outprice,c_num);
return commodityDao.istCommodity(c);
}
public int delCommodityById(String c_id) {
return commodityDao.delCommodityById(c_id);
}
}
welcome.jsp页面（部分代码）
<form method="post" action="/web06/istCommodityServlet">
<table style="border: 1px solid black; margin:0 auto;">
<td colspan="1" style="width:130px;" >商品名称:<input type="text" name="c_name" /></td>
<td style="width:150px;" >商品产地:<input type="text" name="c_madein" /></td>
<td style="width:130px;" >商品类型:
<select name="c_type">
<%
for(Commoditytype ct:ctList){
%>
<option value="<%=ct.getCt_id() %>"><%=ct.getCt_name() %></option>
<%
}
%>
</select>
</td>
<td style="width:130px;" >商品进价:<input type="text" name="c_inprice" /></td>
<td style="width:130px;" >商品售价:<input type="text" name="c_outprice" /></td>
<td style="width:130px;" >商品库存:<input type="text" name="c_num" /></td>
<td style="width:130px;" ><input type="submit" name="新增" /></td>
<!-- 商品列表展示 -->
<tr>
<td>商品编号</td><td>商品名称</td><td>商品产地</td><td>商品类型</td><td>商品进价</td><td>商品售价</td><td>商品库存</td><td>编辑|删除</td>
</tr>
<%
if(cList != null && cList.size() > 0){
for(Commodity c:cList){
%>
<tr>
<td><%=c.getC_id() %></td><td><%=c.getC_name() %></td><td><%=c.getC_madein() %></td><td><%=c.getCt().getCt_name() %></td><td><%=c.getC_inprice() %></td><td><%=c.getC_outprice() %></td><td><%=c.getC_num() %></td><td><a href="/web06/toupdateCommodityByid?c_id=<%=c.getC_id() %>">编辑</a>|<a href="/web06/deleteCommodityById?c_id=<%=c.getC_id() %>">删除</a></td>
</tr>
<%
}
}
%>
</table>
</form>
Servlet(ist\del)
public class IstCommodityServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
req.setCharacterEncoding("utf-8");
resp.setCharacterEncoding("utf-8");
String c_name = req.getParameter("c_name");
String c_madein = req.getParameter("c_madein");
String c_type = req.getParameter("c_type");
Integer c_inprice = new Integer(req.getParameter("c_inprice"));
Integer c_outprice = new Integer(req.getParameter("c_outprice"));
Integer c_num = new Integer(req.getParameter("c_num"));
int line = new CommodityController().istCommodity(c_name,c_madein,c_type,c_inprice,c_outprice,c_num);
if(line>0) {
HttpSession session = req.getSession();
List<Commodity> cList = new CommodityController().getCommodityList();
session.setAttribute("cList", cList);
List<Commoditytype> ctList = new CommoditytypeController().getCommoditytypeList();
session.setAttribute("ctList", ctList);
resp.sendRedirect("/web06/welcome.jsp");
}else {
}
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doGet(req, resp);
}
}
public class DeleteCommodityById extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
req.setCharacterEncoding("utf-8");
resp.setCharacterEncoding("utf-8");
String c_id = req.getParameter("c_id");
int line = new CommodityController().delCommodityById(c_id);
if(line>0) {
HttpSession session = req.getSession();
List<Commodity> cList = new CommodityController().getCommodityList();
session.setAttribute("cList", cList);
List<Commoditytype> ctList = new CommoditytypeController().getCommoditytypeList();
session.setAttribute("ctList", ctList);
resp.sendRedirect("/web06/welcome.jsp");
}else {
}
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doGet(req, resp);
}
}