商品浏览记录的制作！一点问题 - 黑马程序员技术交流社区

这里是描述商品的JavaBean和map集合存储信息，相当简单部分
类：product
/*
* 建立一个javaBean形式的Product
*/
public class Product implements Serializable{
private String id;
private String name;
private String price;
private String numb;
public Product() {
super();
}
public Product(String id, String name, String price, String numb) {
this.id = id;
this.name = name;
this.price = price;
this.numb = numb;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPrice() {
return price;
}
public void setPrice(String price) {
this.price = price;
}
public String getNumb() {
return numb;
}
public void setNumb(String numb) {
this.numb = numb;
}
}
类：DB
public class DB {
//这里将map作为成员变量
private static Map<String, Product> map = new TreeMap<String, Product>();
/*
问题就在这里，如何用hashMap让map集合中的商品按下面的编号进行存储,键为编号
*/
static{
map.put("1", new Product("1", "衬衫", "38", "5"));
map.put("2", new Product("2", "短裤", "68", "2"));
map.put("3", new Product("3", "板鞋", "88", "1"));
map.put("4", new Product("4", "袜子", "18", "8"));
}
public static Product findById(String id){
return map.get(id);
}
public static Map<String, Product> findAll(){
return map;
}
}

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/*
*这里是查找所有商品和浏览记录的部分。都是利用请求转发，让其他模块显示
*/
类:FindAll
public class FindAll extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
/*
* 由于根据显示单独一块功能，所以这里在请求转发之前，
* 只需要获取到存取商品信息的map，缓存在request中，将其传走即可
*/
Map<String, Product> map = DB.findAll();
request.setAttribute("pros", map);
request.getRequestDispatcher("/showAll").forward(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}
//查找一个商品的信息，并将请求转发
类：FindOne
public class FindOne extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String id = request.getParameter("id");
Product pt = DB.findById(id);
request.setAttribute("pro", pt);
request.getRequestDispatcher("/showOne").forward(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}

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/*
*这里将请求转发过来的信息处理之后，给浏览器，有显示所有和单一商品
*/
类：ShowAll
public class ShowAll extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=utf-8");
PrintWriter pw = response.getWriter();
/*
* 构建一个表格
*/
pw.print("<div align=center>商品信息汇总表</div><hr width=300 align=center/>");
pw.print("<table border=1 align=center>");
pw.print("<tr>");
pw.print("<td>编号</td>");
pw.print("<td>名称</td>");
pw.print("<td>价格</td>");
pw.print("<td>数量</td>");
pw.print("<td>查看</td>");
pw.print("</tr>");
Map<String, Product> pros = (Map<String, Product>) request.getAttribute("pros");
if(pros!=null){
for ( Entry<String, Product> entry : pros.entrySet()) {
Product pt = entry.getValue();
pw.print("<tr>");
pw.write("<td>"+pt.getId()+"</td>");
pw.write("<td>"+pt.getName()+"</td>");
pw.write("<td>"+pt.getPrice()+"</td>");
pw.write("<td>"+pt.getNumb()+"</td>");
pw.write("<td><a href='/HE02/findOne?id="+pt.getId()+"'>详情</a></td>");
pw.print("</tr>");
}
}
pw.print("</table><br/><br/><br/>");
pw.write("<div align=center>商品浏览记录<hr width=300 align=center />");
Cookie[] cookies = request.getCookies();
if(cookies !=null){
for (Cookie cookie : cookies) {
if("ids".equals(cookie.getName())){
String[] ids = cookie.getValue().split(",");
for (int i=0;i<ids.length;i++) {
Product pt = DB.findById(ids[i]);
pw.write((i+1)+":<a href=/HE02/findOne?id="+pt.getId()+">"+pt.getName()+"</a><br/>");
}
}
}
}
pw.write("</div>");
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}
类：ShowOne
public class ShowOne extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=utf-8");
//得到需要显示的商品
Product pt = (Product) request.getAttribute("pro");
//输出给浏览器
show(response, pt);
StringBuilder sb = new StringBuilder();
sb.append(pt.getId());
//更新cookies信息
Cookie cookie = updateCookie(request, pt, sb);
response.addCookie(cookie);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
public void show(HttpServletResponse response, Product pt)
throws IOException {
PrintWriter pw = response.getWriter();
pw.write("<div align=center>");
pw.write("商品详情 <hr width=300 align=center/>");
pw.write("商品："+pt.getName()+" 甩卖："+pt.getPrice());
pw.write("<a href='/HE02/findAll'><br/>返回商品列表</a>");
pw.write("</div>");
}
public Cookie updateCookie(HttpServletRequest request, Product pt,
StringBuilder sb) {
Cookie[] cookies = request.getCookies();
if(cookies!=null){
for (Cookie ck : cookies) {
if(ck.getName().equals("ids")){
String[] cookie = ck.getValue().split(",");
for (String id : cookie) {
if(!id.equals(pt.getId())){
sb.append(","+id);
}
}
}
}
}
Cookie cookie = new Cookie("ids", sb.toString());
cookie.setMaxAge(60);
cookie.setPath("/");
return cookie;
}
}

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