新闻发布系统项目

增删改查

下面来看看我们真实的需要做的

新闻发布系统项目

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新闻发布系统项目

添加新闻===文件上传

新闻发布系统项目

编辑新闻----修改删除

新闻发布系统项目

添加主题===分类

新闻发布系统项目

编辑主题

新闻发布系统项目

web项目里后台的分层

新闻发布系统项目

一：先说登录主要代码从我的数据库里拿数据，servlet调用，然后被前台调用。代码如下：

@Override
public boolean isLogin(UserInfo info) throws Exception {
        boolean flag=false;
        String sql="select count(*) from login where username=? and userpwd=?";
        ResultSet rs=executeQuery(sql, info.getUserName(),info.getUserPwd());
if (rs.next()) {
int count=rs.getInt(1);
if(count>0){
                flag=true;
            }
        }
return flag;
    }

我的servlet调用===判断加效验===加我的注销===移除session记录的账户

request.setCharacterEncoding("utf-8");
if (request.getParameter("uname")!=null) {
            String uname=request.getParameter("uname");
            String upwd=request.getParameter("upwd");

//拼接成一个用户对象
            UserInfo info=new UserInfo();
            info.setUserName(uname);
            info.setUserPwd(upwd);

            IUserInfoService service=new UserInfoService();
try {
                boolean flag = service.isLogin(info);
if (flag) {  //登录成功
//3.记录session
                    request.getSession().setAttribute("uname", uname);
                    request.setAttribute("loginsuccess","true");
//4.转发或者重定向   转发不需要加项目名称
                    request.getRequestDispatcher("/NewsServlet").forward(request, response);
return;
                }
            } catch (Exception e) {
                e.printStackTrace();
            }

        }
if ("".equals(request.getParameter("uname")) || "".equals(request.getParameter("upwd"))) {
            request.setAttribute("longinfailure","true");
            request.getRequestDispatcher("/NewsServlet").forward(request, response);
return;
        }

        request.setCharacterEncoding("utf-8");

if(request.getSession().getAttribute("uname")!=null){
            request.setCharacterEncoding("utf-8");

            request.getSession().removeAttribute("uname");
//重定向
            response.sendRedirect("/News/NewsServlet");
return;
        }

我的页面调用：

<script type="text/javascript">

<%if("true".equals(request.getAttribute("longinfailure"))){%>
    alert("用户名或密码为空！");
<%}%>

</script>

</head>

<body>
    <div id="header">
        <div id="top_login">
            <form action="<%=path%>/UserInfoNewServlet" method="post">
                <label> 登录名 </label> <input type="text" id="uname" name="uname"
                    value="" class="login_input" /> <label> 密&#160;&#160;码 </label> <input
                    type="password" id="upwd" name="upwd" value="" class="login_input" />
                <input type="submit" class="login_sub" value="登录" />

二：下面说说我的分页
定义了一个util实体包供我分页使用

package cn.news.util;

import java.util.List;

import cn.news.entity.NewsInfo;

public class Page {
// 当前页
private int pageIndex;
// 页面总记录数
private int pageSize;
// 本业显示真实数据
private List<NewsInfo> list;
// 总页数
private int totalPages;
// 总记录数
private int totalRecords;

public int getPageIndex() {
return pageIndex;
    }

public void setPageIndex(int pageIndex) {
this.pageIndex = pageIndex;
    }

public int getPageSize() {
return pageSize;
    }

public void setPageSize(int pageSize) {
this.pageSize = pageSize;
    }

public List<NewsInfo> getList() {
return list;
    }

public void setList(List<NewsInfo> list) {
this.list = list;
    }

public int getTotalPages() {
return totalPages;
    }

public void setTotalPages(int totalPages) {
this.totalPages = totalPages;
    }

public int getTotalRecords() {
return totalRecords;
    }

public void setTotalRecords(int totalRecords) {
this.totalRecords = totalRecords;
    }

}

主要从数据库里拿到的分页代码如下：

@Override
public List<NewsInfo> getPageInfos(int pageIndex, int pageSize) throws Exception {
        List<NewsInfo> list=new ArrayList<NewsInfo>();

        String sql="SELECT * FROM newinfo LIMIT ?,?";
        rs=executeQuery(sql,(pageIndex-1)*pageSize,pageSize);
if (rs!=null) {
while (rs.next()) {
                NewsInfo info=new NewsInfo();
int nid=rs.getInt("nid");
                String ntitle=rs.getString("ntitle");
                String nauthor=rs.getString("nauthor");
                Date npublisherdate=rs.getDate("npublisherdate");
                String ncontent=rs.getString("ncontent");
int tid=rs.getInt("tid");

                info.setNauthor(nauthor);
                info.setNcontent(ncontent);
                info.setNid(nid);
                info.setNpublisherdate(npublisherdate);
                info.setNtitle(ntitle);
                info.setTid(tid);

                list.add(info);
            }
        }
return list;
    }

@Override
public int selectnewsall() throws Exception {
        String sql="SELECT count(1) FROM newinfo";
int count = 0;
        ResultSet rs = executeQuery(sql);
if (rs.next()) {
            count = rs.getInt(1);
        }

return count;
    }

servlet调用：

    public void pagenews(HttpServletRequest request,HttpServletResponse response) {
        IUserInfoService daoInfoService = new UserInfoService();
try {
            Page oaPage = new Page();
// 默认三条数据
int pageSize = 3;
            oaPage.setPageSize(pageSize);
// pageIndex(当前页)
int myindex = 1;

            String pageIndex = request.getParameter("pageIndex");
if (null!=pageIndex && (!pageIndex.equals(""))) {
                myindex = Integer.parseInt(pageIndex);
            }

// 总页数赋值=总记录数/pageSize
int mytotalPages = 0;
int ipages = daoInfoService.selectnewsall();
if (ipages % pageSize == 0) {
                mytotalPages = ipages / pageSize;
            } else {
                mytotalPages = ipages / pageSize + 1;
            }
            oaPage.setTotalPages(mytotalPages);
if(myindex>oaPage.getTotalPages()){
                myindex=oaPage.getTotalPages();    
                System.out.println(myindex+"1");
            }
            System.out.println("=================================");
if (myindex<1) {
                myindex=1;
                System.out.println(myindex+"2");
            }
            oaPage.setPageIndex(myindex);
// 泛型数据赋值
            List<NewsInfo> list = daoInfoService.getPageInfos(oaPage.getPageIndex(), pageSize);
            oaPage.setList(list);

// 将泛型集合，放入request作用域
            request.setAttribute("list", oaPage);
// 转发index.jsp 转发不用加名称
            

        } catch (Exception e) {

            e.printStackTrace();
        }
    }
public void pageNews(HttpServletRequest request,HttpServletResponse response) {
        IUserInfoService daoInfoService = new UserInfoService();
try {
            Page oaPage = new Page();
// 默认三条数据
int pageSize = 3;
            oaPage.setPageSize(pageSize);
// pageIndex(当前页)
int myindex = 1;

            String pageIndex = request.getParameter("pageIndex");
if (null!=pageIndex && (!pageIndex.equals(""))) {
                myindex = Integer.parseInt(pageIndex);
            }

// 给当前页赋值

// 总页数赋值=总记录数/pageSize
int mytotalPages = 0;
int ipages = daoInfoService.selectnewsall();
if (ipages % pageSize == 0) {
                mytotalPages = ipages / pageSize;
            } else {
                mytotalPages = ipages / pageSize + 1;
            }
            oaPage.setTotalPages(mytotalPages);
if(myindex>oaPage.getTotalPages()){
                myindex=oaPage.getTotalPages();    
                System.out.println(myindex+"1");
            }

if (myindex<1) {
                myindex=1;
                System.out.println(myindex+"2");
            }
            oaPage.setPageIndex(myindex);
// 泛型数据赋值
            List<NewsInfo> list = daoInfoService.getPageInfos(oaPage.getPageIndex(), pageSize);
            oaPage.setList(list);

// 将泛型集合，放入request作用域
            request.setAttribute("list", oaPage);
// 转发index.jsp 转发不用加名称
            
            } catch (Exception e) {
            e.printStackTrace();
            }
    }

dopost

if(request.getParameter("pageIndex")!=null){
            pageNews(request, response);
            request.getRequestDispatcher("/newspages/admin.jsp").forward(request,response);
return;
        }

pagenews(request, response);
        request.getRequestDispatcher("/index.jsp").forward(request,response);

页面调用servlet显示给顾客

<p align="right">
                        当前页数:[<%=page2.getPageIndex()%>/<%=page2.getTotalPages()%>]&nbsp;
<a
                            href="<%=path%>/NewsServlet?pageIndex=<%=page2.getPageIndex() - 1%>">上一页</a>
                        <a
                            href="<%=path%>/NewsServlet?pageIndex=<%=page2.getPageIndex() + 1%>">下一页</a>
                        <a
                            href="<%=path%>/NewsServlet?pageIndex=<%=page2.getTotalPages()%>">末页</a>
                    </p>

登陆后显示的页数

<p align="right"> 当前页数:[${list.pageIndex}/${list.totalPages}]&nbsp;
<a href="${pageContext.request.contextPath}/NewsServlet?pageIndex=${list.pageIndex-1}">上一页</a>&nbsp; 
<a href="${pageContext.request.contextPath}/NewsServlet?pageIndex=${list.pageIndex+1}">下一页</a>&nbsp; 
<a href="${pageContext.request.contextPath}/NewsServlet?pageIndex=${list.totalPages}">末页</a> </p>

三：页面显示数据库里的数据====查找
主要查找Dao层的代码：

@Override
public List<NewsInfo> findAll() throws Exception {
        List<NewsInfo> list=new ArrayList<NewsInfo>();

        String sql="select * from newinfo";
        rs=executeQuery(sql);
if (rs!=null) {
while (rs.next()) {
                NewsInfo info=new NewsInfo();
int nid=rs.getInt("nid");
                String ntitle=rs.getString("ntitle");
                String nauthor=rs.getString("nauthor");
                Date npublisherdate=rs.getDate("npublisherdate");
                String ncontent=rs.getString("ncontent");
int tid=rs.getInt("tid");

                info.setNauthor(nauthor);
                info.setNcontent(ncontent);
                info.setNid(nid);
                info.setNpublisherdate(npublisherdate);
                info.setNtitle(ntitle);
                info.setTid(tid);

                list.add(info);
            }
        }
return list;
    }

将数据用循环显示到页面在我的主页面写：

<ul class="classlist">
                    <%
                        Page page2 = (Page) request.getAttribute("list");
for (NewsInfo item : page2.getList()) {
%>
                    <li><a href="<%=path%>/news_read.jsp"><%=item.getNtitle()%>
                    </a><span><%=item.getNpublisherdate()%></span></li>
                    <%
                        }
%>

四：删除数据主要数据：

@Override
public boolean deleteNews(int id) throws Exception {
        String sql="delete from newinfo where nid=?";
        boolean flag=false;
int count = exeuteUpdate(sql,id);
if (count>0) {
            flag=true;
        }
return flag;
    }

el表达式：

<c:if test="${desuccess!=null}">
<script type="text/javascript">
alert("删除成功！！！");
</script>
</c:if>
</head>
<body>
    <div id="main">
       <div>
        <iframe src="<%=path %>/newspages/console_element/top.jsp" scrolling="no" frameborder="0" width="947px" height="180px"></iframe>
      </div> 
      <div id="opt_list">
         <iframe src="<%=path%>/newspages/console_element/left.jsp" scrolling="no" frameborder="0" width="130px"></iframe>
      </div>
      <div id="opt_area"> 
        <ul class="classlist">
     <c:forEach var="item" items="${list.list}">
         <li> ${item.ntitle}<span> 作者：${item.nauthor}                                          
&#160;&#160;&#160;&#160; <a href='<%=path%>/NewsServlet?upid=${item.nid}'>修改</a> &#160;&#160;&#160;&#160; 
<a href='${pageContext.request.contextPath}/NewsServlet?deid=${item.nid}'>删除</a> 
            </span> 
            </li>
     </c:forEach>

<li><a href="${pageContext.request.contextPath}/NewsServlet?xin=xin" target="_parent">添加新闻</a></li>
<li><a href="${pageContext.request.contextPath}/NewsServlet?kin=kin" target="_parent">编辑新闻</a></li>
所有的dopost数据：

    if (null!=request.getParameter("upid")) {
            System.out.println("1");
return;
        }
if (null!=request.getParameter("deid")) {
            System.out.println("2");
            IUserInfoService service=new UserInfoService();
            String deid=request.getParameter("deid");
            System.out.println(deid);
            Integer id=Integer.parseInt(deid);
            boolean flag=false;
try {
                flag=service.deleteNews(id);
            } catch (Exception e) {
// TODO Auto-generated catch block
                e.printStackTrace();
            }
            request.setAttribute("desuccess", flag);
            pageNews(request, response);
            request.getRequestDispatcher("/newspages/admin.jsp").forward(request, response);        
return;
        }
if("true".equals(request.getAttribute("loginsuccess"))){
            System.out.println("3");
            pageNews(request, response);
            request.getRequestDispatcher("/newspages/admin.jsp").forward(request, response);
return;
        }
if (request.getParameter("kin")!=null) {//index
            pageNews(request, response);
            request.getRequestDispatcher("/newspages/admin.jsp").forward(request,response);
return;
        }
if(request.getParameter("pageIndex")!=null){
            pageNews(request, response);
            request.getRequestDispatcher("/newspages/admin.jsp").forward(request,response);
return;
        }
if (request.getParameter("xin")!=null) {

try {
                    addnews(request, response);
                    request.getRequestDispatcher("/newspages/news_add.jsp").forward(request, response);
                    IUserInfoService infoService=new UserInfoService();
                    List<NewsInfo> all = infoService.findAll();
if (all!=null) {
                        request.getRequestDispatcher("/newspages/admin.jsp").forward(request, response);
                    }else {
                        request.getRequestDispatcher("/newspages/news_add.jsp").forward(request, response);
                    }
                } catch (Exception e) {
// TODO Auto-generated catch block
                    e.printStackTrace();
                }
return;
        }
        pagenews(request, response);
        request.getRequestDispatcher("/index.jsp").forward(request,response);

今天小编就到这里了

剩余修改下期详解

希望给大家的知识

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