《黑马旅游网》综合案例day02
9. 优化Servlet
9.1目的
减少Servlet的数量，现在是一个功能一个Servlet，将其优化为一个模块一个Servlet，相当于在数据库中一张表对应一个Servlet，在Servlet中提供不同的方法，完成用户的请求。
Idea控制台中文乱码解决：-Dfile.encoding=gb2312
9.2 BaseServlet编写：
public class BaseServlet extends HttpServlet {
@Override
protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//System.out.println("baseServlet的service方法被执行了...");
//完成方法分发
//1.获取请求路径
String uri = req.getRequestURI(); // /travel/user/add
System.out.println("请求uri:"+uri);// /travel/user/add
//2.获取方法名称
String methodName = uri.substring(uri.lastIndexOf('/') + 1);
System.out.println("方法名称："+methodName);
//3.获取方法对象Method
//谁调用我？我代表谁
System.out.println(this);//UserServlet的对象cn.itcast.travel.web.servlet.UserServlet@4903d97e
try {
//获取方法
Method method = this.getClass().getMethod(methodName, HttpServletRequest.class, HttpServletResponse.class);
//4.执行方法
//暴力反射
//method.setAccessible(true);
method.invoke(this,req,resp);
} catch (NoSuchMethodException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
}
}
9.3 UserServlet改写
将之前的Servlet实现的功能，抽取到UserServlet中的不同方法中实现，并且将UserService创建抽取到成员变量位置
@WebServlet("/user/*") // /user/add /user/find
public class UserServlet extends BaseServlet {
//声明UserService业务对象
private UserService service = new UserServiceImpl();
/**
* 注册功能
* @param request
* @param response
* @throws ServletException
* @throws IOException
*/
public void regist(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//验证校验
String check = request.getParameter("check");
//从sesion中获取验证码
HttpSession session = request.getSession();
String checkcode_server = (String) session.getAttribute("CHECKCODE_SERVER");
session.removeAttribute("CHECKCODE_SERVER");//为了保证验证码只能使用一次
//比较
if(checkcode_server == null || !checkcode_server.equalsIgnoreCase(check)){
//验证码错误
ResultInfo info = new ResultInfo();
//注册失败
info.setFlag(false);
info.setErrorMsg("验证码错误");
//将info对象序列化为json
ObjectMapper mapper = new ObjectMapper();
String json = mapper.writeValueAsString(info);
response.setContentType("application/json;charset=utf-8");
response.getWriter().write(json);
return;
}
//1.获取数据
Map<String, String[]> map = request.getParameterMap();
//2.封装对象
User user = new User();
try {
BeanUtils.populate(user,map);
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
//3.调用service完成注册
//UserService service = new UserServiceImpl();
boolean flag = service.regist(user);
ResultInfo info = new ResultInfo();
//4.响应结果
if(flag){
//注册成功
info.setFlag(true);
}else{
//注册失败
info.setFlag(false);
info.setErrorMsg("注册失败!");
}
//将info对象序列化为json
ObjectMapper mapper = new ObjectMapper();
String json = mapper.writeValueAsString(info);
//将json数据写回客户端
//设置content-type
response.setContentType("application/json;charset=utf-8");
response.getWriter().write(json);
}
/**
* 登录功能
* @param request
* @param response
* @throws ServletException
* @throws IOException
*/
public void login(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//1.获取用户名和密码数据
Map<String, String[]> map = request.getParameterMap();
//2.封装User对象
User user = new User();
try {
BeanUtils.populate(user,map);
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
//3.调用Service查询
// UserService service = new UserServiceImpl();
User u = service.login(user);
ResultInfo info = new ResultInfo();
//4.判断用户对象是否为null
if(u == null){
//用户名密码或错误
info.setFlag(false);
info.setErrorMsg("用户名密码或错误");
}
//5.判断用户是否激活
if(u != null && !"Y".equals(u.getStatus())){
//用户尚未激活
info.setFlag(false);
info.setErrorMsg("您尚未激活，请激活");
}
//6.判断登录成功
if(u != null && "Y".equals(u.getStatus())){
request.getSession().setAttribute("user",u);//登录成功标记
//登录成功
info.setFlag(true);
}
//响应数据
ObjectMapper mapper = new ObjectMapper();
response.setContentType("application/json;charset=utf-8");
mapper.writeValue(response.getOutputStream(),info);
}
/**
* 查询单个对象
* @param request
* @param response
* @throws ServletException
* @throws IOException
*/
public void findOne(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//从session中获取登录用户
Object user = request.getSession().getAttribute("user");
//将user写回客户端
ObjectMapper mapper = new ObjectMapper();
response.setContentType("application/json;charset=utf-8");
mapper.writeValue(response.getOutputStream(),user);
}
/**
* 退出功能
* @param request
* @param response
* @throws ServletException
* @throws IOException
*/
public void exit(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//1.销毁session
request.getSession().invalidate();
//2.跳转登录页面
response.sendRedirect(request.getContextPath()+"/login.html");
}
/**
* 激活功能
* @param request
* @param response
* @throws ServletException
* @throws IOException
*/
public void active(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//1.获取激活码
String code = request.getParameter("code");
if(code != null){
//2.调用service完成激活
//UserService service = new UserServiceImpl();
boolean flag = service.active(code);
//3.判断标记
String msg = null;
if(flag){
//激活成功
msg = "激活成功，请<a href='login.html'>登录</a>";
}else{
//激活失败
msg = "激活失败，请联系管理员!";
}
response.setContentType("text/html;charset=utf-8");
response.getWriter().write(msg);
}
}
}
9.4页面路径改写
register.html
//校验通过，发送ajax请求，提交表单数据 username=zhangsan&password=123
$.post("user/regist",$(this).serialize(),function(data){
//处理服务器的数据 data {flag:true,errorMsg:"注册失败"}
if(data.flag){
//注册成功，跳转成功页面
location.href="register_ok.html";
}else{
//注册失败
$("#errorMsg").html(data.errorMsg);
}
});
login.html
//2.发送ajax请求，提交表单数据
$.post("user/login",$("#loginForm").serialize(),function(data){
//data:{flag:false,errorMsg:''}
if(data.flag){
//登录成功
location.href="index.html";
}else{
//登陆失败
$("#errorMsg").html(data.errorMsg);
}
});
header.html
$(function(){
$.get("user/findOne",{
},function(data){
//{uid:1,name:'李四'}
var msg="欢迎回来,"+data.name;
$("#span_username").html(msg);
});
});
UserServiceImpl发送邮件
//3.激活邮件发送，邮件正文？
String content = "<a href='http://localhost/travel/user/active?code="+user.getCode()+"'+user.get>点击激活【黑马旅游网】</a>";
MailUtils.sendMail(user.getEmail(),content,"激活邮件");
-
分类数据展示
10.1效果：
10.2 分析：
10.3代码实现：10.3.1后台代码
CategoryServlet@WebServlet("/category/*") public class CategoryServlet extends BaseServlet { private CategoryService service = new CategoryServiceImpl(); /** * 查询所有 * @param request * @param response * @throws ServletException * @throws IOException */ public void findAll(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //1.调用service查询所有 List<Category> cs = service.findAll(); //2.序列化json返回 /* ObjectMapper mapper = new ObjectMapper(); response.setContentType("application/json;charset=utf-8"); mapper.writeValue(response.getOutputStream(),cs);*/ writeValue(cs,response); } }CategoryServicepublic class CategoryServiceImpl implements CategoryService { private CategoryDao categoryDao = new CategoryDaoImpl(); @Override public List<Category> findAll() { return categoryDao.findAll(); } }CategoryDaopublic class CategoryDaoImpl implements CategoryDao { private JdbcTemplate template = new JdbcTemplate(JDBCUtils.getDataSource()); @Override public List<Category> findAll() { String sql = "select * from tab_category "; return template.query(sql,new BeanPropertyRowMapper<Category>(Category.class)); } }在
BaseServlet中封装了序列化json的方法/** * 直接将传入的对象序列化为json，并且写回客户端 * @param obj */ public void writeValue(Object obj,HttpServletResponse response) throws IOException { ObjectMapper mapper = new ObjectMapper(); response.setContentType("application/json;charset=utf-8"); mapper.writeValue(response.getOutputStream(),obj); } /** * 将传入的对象序列化为json，返回 * @param obj * @return */ public String writeValueAsString(Object obj) throws JsonProcessingException { ObjectMapper mapper = new ObjectMapper(); return mapper.writeValueAsString(obj); }10.3.2前台代码
hader.html加载后，发送ajax请求，请求category/findAll//查询分类数据 $.get("category/findAll",{ },function (data) { //[{cid:1,cname:国内游},{},{}] var lis = '<li class="nav-active"><a href="index.html">首页</a></li>'; //遍历数组,拼接字符串(<li>) for (var i = 0; i < data.length; i++) { var li = '<li><a href="route_list.html">'+data[i].cname+'</a></li>'; lis += li; } //拼接收藏排行榜的li,<li><a href="favoriterank.html">收藏排行榜</a></li> lis+= '<li><a href="favoriterank.html">收藏排行榜</a></li>'; //将lis字符串，设置到ul的html内容中 $("#category").html(lis); });10.4对分类数据进行缓存优化
分析发现，分类的数据在每一次页面加载后都会重新请求数据库来加载，对数据库的压力比较大，而且分类的数据不会经常产生变化，所有可以使用redis来缓存这个数据。
分析：
10.5优化代码实现
期望数据中存储的顺序就是将来展示的顺序，使用redis的sortedset@Override public List<Category> findAll() { //1.从redis中查询 //1.1获取jedis客户端 Jedis jedis = JedisUtil.getJedis(); //1.2可使用sortedset排序查询 Set<String> categorys = jedis.zrange("category", 0, -1); List<Category> cs = null; //2.判断查询的集合是否为空 if (categorys == null || categorys.size() == 0) { System.out.println("从数据库查询...."); //3.如果为空,需要从数据库查询,在将数据存入redis //3.1 从数据库查询 cs = categoryDao.findAll(); //3.2 将集合数据存储到redis中的 category的key for (int i = 0; i < cs.size(); i++) { jedis.zadd("category", cs.get(i).getCid(), cs.get(i).getCname()); } } else { System.out.println("从redis中查询....."); //4.如果不为空,将set的数据存入list cs = new ArrayList<Category>(); for (String name : categorys) { Category category = new Category(); category.setCname(name); cs.add(category); } } return cs; } -
旅游线路的分页展示
点击了不同的分类后，将来看到的旅游线路不一样的。通过分析数据库表结构，发现，旅游线路表和分类表时一个多对一的关系
查询不同分类的旅游线路sql
Select * from tab_route where cid = ?;11.1类别id的传递
Redis中查询score（cid）
public class CategoryServiceImpl implements CategoryService { private CategoryDao categoryDao = new CategoryDaoImpl(); @Override public List<Category> findAll() { //1.从redis中查询 //1.1获取jedis客户端 Jedis jedis = JedisUtil.getJedis(); //1.2可使用sortedset排序查询 //Set<String> categorys = jedis.zrange("category", 0, -1); //1.3查询sortedset中的分数(cid)和值(cname) Set<Tuple> categorys = jedis.zrangeWithScores("category", 0, -1); List<Category> cs = null; //2.判断查询的集合是否为空 if (categorys == null || categorys.size() == 0) { System.out.println("从数据库查询...."); //3.如果为空,需要从数据库查询,在将数据存入redis //3.1 从数据库查询 cs = categoryDao.findAll(); //3.2 将集合数据存储到redis中的 category的key for (int i = 0; i < cs.size(); i++) { jedis.zadd("category", cs.get(i).getCid(), cs.get(i).getCname()); } } else { System.out.println("从redis中查询....."); //4.如果不为空,将set的数据存入list cs = new ArrayList<Category>(); for (Tuple tuple : categorys) { Category category = new Category(); category.setCname(tuple.getElement()); category.setCid((int)tuple.getScore()); cs.add(category); } } return cs; } }页面传递cid
header.html传递cidvar li = '<li><a href="route_list.html?cid='+data[i].cid+'">'+data[i].cname+'</a></li>';route_list.html获取cid$(function () { var search = location.search; //alert(search);//?id=5 // 切割字符串，拿到第二个值 var cid = search.split("=")[1]; });11.2根据id查询不同类别的旅游线路数据
分页展示旅游线路数据：
11.2.1
11.2.2编码
1.客户端代码编写
<script> $(function () { var search = location.search; //alert(search);//?id=5 // 切割字符串，拿到第二个值 var cid = search.split("=")[1]; //alert(cid); //当页码加载完成后，调用load方法，发送ajax请求加载数据 load(cid); }); function load(cid, currentPage){ //发送Ajax请求，请求route/pageQuery,传递cid $.get("route/pageQuery",{ cid:cid,currentPage:currentPage},function (pb) { //解析pagebean数据，展示到页面上 //1.分页工具条数据展示 //1.1 展示总页码和总记录数 $("#totalPage").html(pb.totalPage); $("#totalCount").html(pb.totalCount); /* <li><a href="">首页</a></li> <li class="threeword"><a href="#">上一页</a></li> <li class="curPage"><a href="#">1</a></li> <li><a href="#">2</a></li> <li><a href="#">3</a></li> <li><a href="#">4</a></li> <li><a href="#">5</a></li> <li><a href="#">6</a></li> <li><a href="#">7</a></li> <li><a href="#">8</a></li> <li><a href="#">9</a></li> <li><a href="#">10</a></li> <li class="threeword"><a href="javascript:;">下一页</a></li> <li class="threeword"><a href="javascript:;">末页</a></li> */ var lis = ""; var firstPage = '<li οnclick="javascipt:load('+cid+')"><a href="javascript:void(0)">首页</a></li>'; //计算上一页页码 var beforeNum = pb.currentPage - 1; var beforePage = ' <li οnclick="javascipt:load('+cid+','+beforeNum+')" class="threeword"><a href="javascript:void(0);">上一页</a></li>'; lis += firstPage; lis += beforePage; //1.2展示分页页码 /* 1.一共展示10个页码，能够达到前5后4的效果 2.如果前边不够5个，后边补齐10个 3.如果后边不足4个，前边补齐10个 */ //定义开始位置begin,结束位置end var begin;//开始位置 var end; //结束位置 //1.要显示10个页码 if(pb.totalPage < 10){ //总页码不够10页 begin = 1; end = pb.totalPage; }else{ //总页码超过10页 begin = pb.currentPage - 5; end = pb.currentPage + 4; //2.如果前边不够5个，后边补齐10个 if(begin < 1){ begin =1; end = begin +9; } //3.如果后边不足4个，前边补齐10个 if(end > pb.totalPage){ end = pb.totalPage; begin = end -9; } } for (var i = begin; i <= end; i++) { var li; //判断当前页码是否等于i if(pb.currentPage == i){ li = '<li class="curPage" οnclick="javascipt:load('+cid+','+i+')"><a href="javascript:void(0)">'+i+'</a></li>'; }else{ //创建页码的li li = '<li οnclick="javascipt:load('+cid+','+i+')"><a href="javascript:void(0)">'+i+'</a></li>'; } //拼接字符串 lis += li; } var lastPage = ' <li class="threeword"><a href="javascript:;">末页</a></li>'; var naxtPage = ' <li class="threeword"><a href="javascript:;">下一页</a></li>'; lis += naxtPage; lis += lastPage; //将内容设置到ul $("#pageNum").html(lis); //2.列表数据展示 var route_lis = ""; for (var i = 0; i < pb.list.length; i++) { //获取{rid:1,rname:"xxx"} var route = pb.list[i]; var li = ' <li>\n' + ' <div class="img"><img src="'+route.rimage+'" style="width: 299px;"></div>\n' + ' <div class="text1">\n' + ' <p>'+route.rname+'</p>\n' + ' <br/>\n' + ' <p>'+route.routeIntroduce+'</p>\n' + ' </div>\n' + ' <div class="price">\n' + ' <p class="price_num">\n' + ' <span>¥</span>\n' + ' <span>'+route.price+'</span>\n' + ' <span>起</span>\n' + ' </p>\n' + ' <p><a href="route_detail.html">查看详情</a></p>\n' + ' </div>\n' + ' </li>'; route_lis += li; } $("#route").html(route_lis); //定位到页面顶部 window.scrollTo(0,0); }); } </script>2.服务器端代码编写
a)创建
PageBean对象public class PageBean<T> { private int totalCount;//总记录数 private int totalPage;//总页数 private int currentPage;//当前页码 private int pageSize;//每页显示的条数 private List<T> list;//每页显示的数据集合 public int getTotalCount() { return totalCount; } public void setTotalCount(int totalCount) { this.totalCount = totalCount; } public int getTotalPage() { return totalPage; } public void setTotalPage(int totalPage) { this.totalPage = totalPage; } public int getCurrentPage() { return currentPage; } public void setCurrentPage(int currentPage) { this.currentPage = currentPage; } public int getPageSize() { return pageSize; } public void setPageSize(int pageSize) { this.pageSize = pageSize; } public List<T> getList() { return list; } public void setList(List<T> list) { this.list = list; } }b)
RouteServlet@WebServlet("/route/*") public class RouteServlet extends BaseServlet { private RouteService routeService = new RouteServiceImpl(); /** * 分页查询 * @param request * @param response * @throws ServletException * @throws IOException */ public void pageQuery(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //1.接受参数 String currentPageStr = request.getParameter("currentPage"); String pageSizeStr = request.getParameter("pageSize"); String cidStr = request.getParameter("cid"); int cid = 0;//类别id //2.处理参数 if(cidStr != null && cidStr.length() > 0){ cid = Integer.parseInt(cidStr); } int currentPage = 0;//当前页码，如果不传递，则默认为第一页 if(currentPageStr != null && currentPageStr.length() > 0){ currentPage = Integer.parseInt(currentPageStr); }else{ currentPage = 1; } int pageSize = 0;//每页显示条数，如果不传递，默认每页显示5条记录 if(pageSizeStr != null && pageSizeStr.length() > 0){ pageSize = Integer.parseInt(pageSizeStr); }else{ pageSize = 5; } //3. 调用service查询PageBean对象 PageBean<Route> pb = routeService.pageQuery(cid, currentPage, pageSize); //4. 将pageBean对象序列化为json，返回 writeValue(pb,response); } }c)
RouteServicepublic class RouteServiceImpl implements RouteService { private RouteDao routeDao = new RouteDaoImpl(); @Override public PageBean<Route> pageQuery(int cid, int currentPage, int pageSize) { //封装PageBean PageBean<Route> pb = new PageBean<Route>(); //设置当前页码 pb.setCurrentPage(currentPage); //设置每页显示条数 pb.setPageSize(pageSize); //设置总记录数 int totalCount = routeDao.findTotalCount(cid); pb.setTotalCount(totalCount); //设置当前页显示的数据集合 int start = (currentPage - 1) * pageSize;//开始的记录数 List<Route> list = routeDao.findByPage(cid,start,pageSize); pb.setList(list); //设置总页数 = 总记录数/每页显示条数 int totalPage = totalCount % pageSize == 0 ? totalCount / pageSize :(totalCount / pageSize) + 1 ; pb.setTotalPage(totalPage); return pb; } }d)
RouteDaopublic class RouteDaoImpl implements RouteDao { private JdbcTemplate template = new JdbcTemplate(JDBCUtils.getDataSource()); @Override public int findTotalCount(int cid) { String sql = "select count(*) from tab_route where cid = ?"; return template.queryForObject(sql,Integer.class,cid); } @Override public List<Route> findByPage(int cid, int start, int pageSize) { String sql = "select * from tab_route where cid = ? limit ? , ?"; return template.query(sql,new BeanPropertyRowMapper<Route>(Route.class),cid,start,pageSize); } }
踩坑：
- 使用redis对分类数据进行缓存优化时，需提前开启：redis-service
127.0.0.1:6379> keys *
1) "category"
127.0.0.1:6379> zrange category 0 -1
1) "\xe9\x97\xa8\xe7\xa5\xa8"
...
127.0.0.1:6379> zrange category 0 -1 withscores
1) "\xe9\x97\xa8\xe7\xa5\xa8"
2) "1"
...
127.0.0.1:6379>
- 问题如下
//发送Ajax请求，请求route/pageQuery,传递cid
$.get("route/pageQuery",{
cid:cid},function (pb) {
//解析pagebean数据，展示到页面上
//1.分页工具条数据展示
//1.1 展示总页码和总记录数
$("#totalPage").html(pb.totalPage);
$("#totalCount").html(pb.totalCount);
});