简单页面（C标签）+java后台+数据库，对前篇文章的改进

冷不防 2021-07-09 10:16 175阅读 0赞

在前两篇的关于简单页面+java后台+数据库的整体中我们可以看到，虽然功能能够实现但是，页面的代码中插入了好多小脚本，这样导致页面的代码不简洁，所以针对这个问题，我们在页面使用c标签；

首先是前端网页的文件：

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addtypes代码：

<body style="background-image:url(bg3.jpg)"> <h1>这是添加新闻界面</h1> <form action="TypesServlet" method="post"> <input type="hidden" value="1" name="type"> 新闻类型：<input type="text" name="typename"/><br/> <input type="submit" value="提交"> </form> </body>

showtypes

<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>//c标签 <body style="background-image:url(bg3.jpg)"> <h1>这是显示页面</h1> <h1>显示类型</h1> <table border="1"> <tr><td>编号</td><td>类型</td><td>操作</td></tr> <c:forEach items="${list}" var="types"> <tr> <td>${types.id}</td><td>${types.typename}</td> <td><a href="TypesServlet?type=3&&id=${types.id}">修改</a>    <a href="TypesServlet?type=4&&id=${types.id}">删除</a></td> </tr> </c:forEach> </table> </body>

updatetypes:

<body style="background-image:url(bg3.jpg)"> <h1>这是显示页面</h1> <h1>显示类型</h1> <table border="1"> <tr><td>编号</td><td>类型</td><td>操作</td></tr> <c:forEach items="${list}" var="types"> <tr> <td>${types.id}</td><td>${types.typename}</td> <td><a href="TypesServlet?type=3&&id=${types.id}">修改</a>    <a href="TypesServlet?type=4&&id=${types.id}">删除</a></td> </tr> </c:forEach> </table> </body>

addnews代码：

<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %> <body style="background-image:url(bg3.jpg)"> <h1>添加内容界面</h1> <form action="NewsServlet" method="post"> <input type="hidden" value="1" name="type"> 标题：<input type="text" name="title"/><br/> 内容：<input type="text" name="contain"/><br/> 作者：<input type="text" name="autor"/><br/> 类型：<select name="typeid"> <c:forEach items="${list}" var="types"> <option value="${types.id}"> ${types.typename }</option> </c:forEach> </select> <input type="submit" value="提交"> </form> </body>

shownews代码：

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%> <body style="background-image:url(bg3.jpg)"> <h1>这是显示页面</h1> <h1>显示内容</h1> <table border="1"> <tr><td>编号</td><td>标题</td><td>内容</td><td>作者</td><td>操作</td></tr> <c:forEach items="${list}" var="news"> <tr> <td>${news.id}</td><td>${news.title}</td><td>${news.contain}</td><td>${news.autor}</td> <td><a href="NewsServlet?type=6&&id=${news.id}">修改</a>    <a href="NewsServlet?type=4&&id=${news.id}">删除</a></td> </tr> </c:forEach> </body>

updatenews：

<body style="background-image:url(bg3.jpg)"> <h1>修改内容页面</h1> <form action="NewsServlet" method="post"> <input type="hidden" value="4" name="type"> <input type="hidden" name="idss" value="${news.id}"/> 标题：<input type="text" name="title" value="${news.title}"/><br/> 内容：<input type="text" name="contain" value="${news.contain}"/><br/> 作者：<input type="text" name="autor" value="${news.autor}"/><br/> <input type="submit" value="提交"> </form> </body>

下面是servlet层的代码

TypeServlet(新闻类型):

package servlet; import java.io.IOException; import java.io.PrintWriter; import java.util.ArrayList; import java.util.List; import javax.servlet.RequestDispatcher; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import entity.types; import service.TypesService; import service.imp.TypesServiceImp; public class TypesServlet extends HttpServlet { /** * */ private static final long serialVersionUID = 1L; public void destroy() { super.destroy(); // Just puts "destroy" string in log } TypesService ts=new TypesServiceImp(); public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("utf-8"); response.setCharacterEncoding("utf-8"); response.setContentType("text/html;charset=utf-8"); PrintWriter out = response.getWriter(); //再调用post方法 this.doPost(request, response); out.flush(); out.close(); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("utf-8"); response.setCharacterEncoding("utf-8"); response.setContentType("text/html;charset=utf-8"); //获取type数值来判断进行增删改查,在页面里面设置了 String type=request.getParameter("type"); if ("1".equals(type)) { //添加方法 System.out.println("haha"); addtypes(request, response); } else if("2".equals(type)){ //查询所有 selectall(request, response); }else if("3".equals(type)){ //单个查询 selectone(request, response); }else if("4".equals(type)){ //删除 ts.delete(Integer.parseInt(request.getParameter("id"))); selectall(request, response); }else if("5".equals(type)){ //修改 update(request, response); } PrintWriter out = response.getWriter(); out.flush(); out.close(); } /***********************添加方法*********************************************************/ public void addtypes(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String typesname=request.getParameter("typename"); int a=ts.addtypes(typesname); if (a>0) { //调用查询方法 selectall(request, response); }else { //进入添加新闻类型页面 response.sendRedirect("addnews.jsp"); } } /***********************查询方法*********************************************************/ public void selectall(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { List<types> list=new ArrayList<types>(); list=ts.selectall(null); request.setAttribute("list", list); RequestDispatcher rd=request.getRequestDispatcher("showtypes.jsp"); rd.forward(request, response); } /***********************修改方法*********************************************************/ public void update(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { int id=Integer.parseInt(request.getParameter("id")); String tname=request.getParameter("types"); types ty=new types(id, tname); ts.update(ty); System.out.println("更新咯"); //调用查询方法 selectall(request, response); } /***********************查询一个方法*********************************************************/ public void selectone(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { int id=Integer.parseInt(request.getParameter("id")); types ty=ts.selectone(id); request.setAttribute("types",ty); RequestDispatcher rd=request.getRequestDispatcher("updatetypes.jsp"); rd.forward(request, response); } public void init() throws ServletException { } }

NewsServlet:

package servlet; import java.io.IOException; import java.io.PrintWriter; import java.util.ArrayList; import java.util.List; import javax.servlet.RequestDispatcher; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import entity.news; import entity.types; import service.NewsService; import service.TypesService; import service.imp.NewsServiceImp; import service.imp.TypesServiceImp; public class NewsServlet extends HttpServlet { NewsService ns=new NewsServiceImp(); TypesService ts=new TypesServiceImp(); public NewsServlet() { super(); } public void destroy() { super.destroy(); // Just puts "destroy" string in log // Put your code here } public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("utf-8"); response.setCharacterEncoding("utf-8"); response.setContentType("text/html;charset=utf-8"); PrintWriter out = response.getWriter(); this.doPost(request, response);//再调用post方法 out.flush(); out.close(); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("utf-8"); response.setCharacterEncoding("utf-8"); response.setContentType("text/html;charset=utf-8"); PrintWriter out = response.getWriter(); //获取type值来判断怎么做 String type=request.getParameter("type"); if ("1".equals(type)) { //添加操作 addnews(request, response); } else if("2".equals(type)){ //修改操作 update(request, response); }else if("3".equals(type)){ //查看 selectall(request, response); }else if("4".equals(type)){ //删除 delate(request, response); }else if("5".equals(type)){ //查看类型 selecttype(request, response); } else if("6".equals(type)){ //查看一个，查询先调用查询一个 selectone(request, response); } out.flush(); out.close(); } /*******添加内容*******************************************************************/ public void addnews(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String title=request.getParameter("title"); String contain=request.getParameter("contain"); String autor=request.getParameter("autor"); String typeid=request.getParameter("typeid"); news n=new news(title, contain, autor, Integer.parseInt(typeid)); int a=ns.addnews(n); if(a>0){ //调用查询方法 selectall(request, response); }else { response.sendRedirect("addnews");//重定向 } } /*******查看所有内容*******************************************************************/ public void selectall(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { List<news> list=ns.selectall(null); request.setAttribute("list", list); request.getRequestDispatcher("shownews.jsp").forward(request, response); } /*******查看类型，为查看服务*******************************************************************/ public void selecttype(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { List<types> list=ts.selectall(null); request.setAttribute("list", list); request.getRequestDispatcher("addnews.jsp").forward(request, response);//转发 } /*******查看一个*******************************************************************/ public void selectone(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { int id=Integer.parseInt(request.getParameter("id")); //System.out.println(id); news ne=ns.selectone(id); request.setAttribute("news",ne); RequestDispatcher rd=request.getRequestDispatcher("updatenews.jsp");//转发 rd.forward(request, response); } /*******修改内容*******************************************************************/ public void update(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { int id=Integer.parseInt(request.getParameter("idss")); String title=request.getParameter("title"); String contain=request.getParameter("contain"); String autor=request.getParameter("autor"); news ne=new news(id, title, contain, autor ); ns.update(ne); System.out.println("更新咯"); //调用查询方法 selectall(request, response); } /*******删除内容*******************************************************************/ public void delate(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { ns.delete(Integer.parseInt(request.getParameter("id"))); selectall(request, response); } public void init() throws ServletException { // Put your code here } }

之后的Service层和Dao层的代码和我之前的两篇文章结合在一起最终都是一样的，之后这整篇文章的例子我也会上传

这篇的打包文件在这：http://download.csdn.net/download/qq\_34178998/9950610

，要注意用两个jar包；

![SouthEast][]

好了这次的博客就更新到这![大笑][laugh.gif]

[Center]: /images/20210708/a70ff65386b54ef1a47e23bb52e83c17.png
[SouthEast]: /images/20210708/385123391dfe43a7b0087e2920ed6aa5.png
[laugh.gif]: /images/20210708/f3ff59fe03bf46749053dfd342b8c3bd.png