JSP综合练习
模拟数据库
package com.wu.db;
import com.wu.pojo.News;
import java.util.ArrayList;
import java.util.List;
public class NewsDB {
public static List<News> list = new ArrayList<News>();
static {
list.add(new News("7.16","学习了JSP的使用以及源码分析"));
list.add(new News("7.14","学习了Servlet,简单的JSP的使用"));
list.add(new News("7.13","学习了Tomcat,Servlet的使用"));
list.add(new News("7.13","学习了Tomcat,Servlet的使用"));
list.add(new News("7.13","学习了Tomcat,Servlet的使用"));
list.add(new News("7.13","学习了Tomcat,Servlet的使用"));
list.add(new News("7.13","学习了Tomcat,Servlet的使用"));
list.add(new News("7.13","学习了Tomcat,Servlet的使用"));
}
}
实体类
package com.wu.pojo;
//实体类,一般放在pojo包下,【 or entity or JavaBeans】
//实体类,只有属性,一般用来映射数据库中的字段 ( O R M )
//私有属性 , 无参构造,有参构造
//get/set方法
//为了方便程序打印,建议加上toString();
public class News {
private String data;
private String content;
public News() {
}
public News(String data, String content) {
this.data = data;
this.content = content;
}
public String getData() {
return data;
}
public void setData(String data) {
this.data = data;
}
public String getContent() {
return content;
}
public void setContent(String content) {
this.content = content;
}
@Override
public String toString() {
return "News{" +
"data='" + data + '\'' +
", content='" + content + '\'' +
'}';
}
}
dao层
package com.wu.dao;
//dao包一般用来存放操作数据库的对象类;
import com.wu.pojo.News;
import java.util.List;
public interface NewsDao {
//获得所有的新闻
public List<News> getAllNews();
}
package com.wu.dao;
import com.wu.db.NewsDB;
import com.wu.pojo.News;
import java.util.List;
//NewsDao的实现类
public class NewsDaoImpl implements NewsDao {
@Override
public List<News> getAllNews() {
List<News> list = NewsDB.list;
return list;
}
}
service层
package com.wu.service;
import com.wu.pojo.News;
import java.util.List;
//service一般存放业务类
public interface NewsService {
//获得所有的新闻
public List<News> getAllNews();
}
package com.wu.service;
import com.wu.dao.NewsDao;
import comwu.dao.NewsDaoImpl;
import com.wu.pojo.News;
import java.util.List;
public class NewsServiceImpl implements NewsService {
//从dao层中取出相应的操作数据库的方法
NewsDao newsDao = new NewsDaoImpl();
@Override
public List<News> getAllNews() {
return newsDao.getAllNews();
}
}
servlet
package com.wu.servlet;
import com.wu.pojo.News;
import com.wu.service.NewsService;
import com.wu.service.NewsServiceImpl;
import org.apache.catalina.Session;
import org.junit.Test;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;
import java.util.List;
public class NewsServlet extends HttpServlet {
NewsService newsService = new NewsServiceImpl();
@Test
public void test(){
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//写代码读取数据存到某个地方,让前端读取;
List<News> allNews = newsService.getAllNews();//从业务层去获得数据中的全部新闻
int i = 1;
for (News allNew : allNews) { //遍历获得每一个新闻
String data = allNew.getData();
String content = allNew.getContent();
//四大作用域
// page(不用它,代表当前页面)
// request(一次请求中有效): 登录注册
// session (一次会话中存在) : 购物车
// application:本质就是Context (全局,所有会话共享) : 广告
//这四个作用域用来存放一些内容或者对象
HttpSession session = req.getSession();
session.setAttribute("data"+i,data);
session.setAttribute("content"+i,content);
System.out.println(session.getAttribute("data"+i));
System.out.println(session.getAttribute("content"+i));
i++;//自增
}
//数据都读取出来了,给你放到session中了,该去访问页面了
resp.sendRedirect("index.jsp");
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doGet(req, resp);
}
}
web.xml
<?xml version="1.0" encoding="UTF-8"?><servlet>
<servlet-name>newsServlet</servlet-name>
<servlet-class>com.wu.servlet.NewsServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>newsServlet</servlet-name>
<url-pattern>/news.do</url-pattern>
</servlet-mapping>
index.jsp
<%@ page import="com.wu.db.NewsDB" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>首页</title>
<%--引入css--%>
<link rel="stylesheet" href="${pageContext.request.contextPath}/statics/layui/css/layui.css">
<%--引入静态资源文件必须带上项目路径位置--%>
<Script src="${pageContext.request.contextPath}/statics/layui/layui.js"></Script>
</head>
<body>
<fieldset class="layui-elem-field layui-field-title" style="margin-top: 30px;">
<legend>常规时间线</legend>
</fieldset>
<ul class="layui-timeline">
<%
for (int i = 1; i <= NewsDB.list.size(); i++) {
%>
<li class="layui-timeline-item">
<i class="layui-icon layui-timeline-axis"></i>
<div class="layui-timeline-content layui-text">
<h3 class="layui-timeline-title">
<%=request.getSession().getAttribute("data"+i)%>
<%--${sessionScope.data1}--%>
</h3>
<p>
<%--${sessionScope.content1}--%>
<%=request.getSession().getAttribute("content"+i)%>
</p>
</div>
</li>
<%
}
%>
<li class="layui-timeline-item">
<i class="layui-icon layui-timeline-axis"></i>
<div class="layui-timeline-content layui-text">
<div class="layui-timeline-title">过去</div>
</div>
</li>
</ul>
</body>
</html>