基本的操作就是连接数据库的进行简单的增删改查,然后数据的回显。此处遇到的主要的问题一个是使用ueditor富文本编辑的时候,需要配置。
其次最需要注意的就是数据库的操作语句以及数据库的连接,新闻表的代码,由于之前已经做过登录,不在附上该操作代码。在操作数据库时,如果频繁的需要连接数据库,那么可以将连接的代码单独写到一个类中去。
1 package dao; 2 3 import java.sql.Connection; 4 import java.sql.DriverManager; 5 import java.sql.PreparedStatement; 6 import java.sql.ResultSet; 7 import java.sql.SQLException; 8 import java.sql.Statement; 9 import java.util.ArrayList; 10 import java.util.List; 11 12 import bean.News; 13 14 public class Newsdao { 15 private static final long serialVersionUID = 1L; 16 // private String driverName="com.mysql.jdbc.Driver"; 17 // private String url="jdbc:mysql://localhost:3306/newsdata?useSSL=false&serverTimezone=UTC"; 18 // private String name="root"; 19 // private String pwd="123456"; 20 static Connection con=null; 21 public static Connection getCon() { 22 String driverName="com.mysql.cj.jdbc.Driver"; 23 String url="jdbc:mysql://localhost:3306/newsdata?useSSL=false&serverTimezone=UTC&allowPublicKeyRetrieval=true"; 24 String name="root"; 25 String pwd="123456"; 26 try { 27 Class.forName(driverName); 28 try { 29 con = DriverManager.getConnection(url, name, pwd); 30 } catch (SQLException e) { 31 e.printStackTrace(); 32 } 33 34 } catch (ClassNotFoundException e) { 35 e.printStackTrace(); 36 } 37 return con; 38 } 39 //添加新闻 40 public boolean addNews(News news) { 41 con=Newsdao.getCon(); 42 boolean flag=false; 43 String sql="insert news(title,type,datetime,content) values('"+news.getTitle()+"','" 44 +news.getType()+"','" 45 +news.getDateTime()+"','" 46 +news.getContent()+"')"; 47 //System.out.println("添加的sql语句"+sql); 48 try { 49 PreparedStatement ps=con.prepareStatement(sql); 50 int i=ps.executeUpdate(); 51 //System.out.println("i的值"+i); 52 ps.close(); 53 con.close(); 54 if(i>0) { 55 flag =true; 56 } 57 } catch (SQLException e) { 58 System.out.println("添加出错啦"); 59 e.printStackTrace(); 60 } 61 62 return flag; 63 } 64 public List<News> selectByID(int id){ 65 con=Newsdao.getCon(); 66 List<News> list=new ArrayList<>(); 67 String sql="select * from news where id="+id+""; 68 System.out.println(sql); 69 Statement state; 70 ResultSet rs; 71 try { 72 state = con.createStatement(); 73 rs=state.executeQuery(sql); 74 while(rs.next()) { 75 News news=new News(); 76 news.setTitle(rs.getString("title")); 77 news.setContent(rs.getString("content")); 78 news.setDateTime(rs.getString("dateTime")); 79 news.setType(rs.getString("type")); 80 ; news.setId(id); 81 list.add(news); 82 //System.out.println(news.getTitle()); 83 } 84 rs.close(); 85 state.close(); 86 con.close(); 87 } catch (SQLException e) { 88 System.out.println("查询出错啦"); 89 e.printStackTrace(); 90 } 91 return list; 92 } 93 94 95 //删除新闻 96 public List<News> selectAll(){ 97 con=Newsdao.getCon(); 98 List<News> list=new ArrayList<News>(); 99 String sql="select * from news"; 100 Statement state; 101 ResultSet rs; 102 try { 103 state = con.createStatement(); 104 rs=state.executeQuery(sql); 105 while(rs.next()) { 106 News news=new News(); 107 news.setId(rs.getInt("id")); 108 news.setTitle(rs.getString("title")); 109 news.setContent(rs.getString("content")); 110 news.setDateTime(rs.getString("dateTime")); 111 news.setType(rs.getString("type")); 112 list.add(news); 113 //System.out.println(news.getType()); 114 } 115 rs.close(); 116 state.close(); 117 con.close(); 118 } catch (SQLException e) { 119 System.out.println("查询出错啦"); 120 e.printStackTrace(); 121 } 122 return list; 123 } 124 125 //修改新闻 126 127 public boolean update(News news) { 128 con=Newsdao.getCon(); 129 boolean flag=false; 130 String sql="update news set title='"+news.getTitle()+"',type='"+news.getType() 131 +"',dateTime='"+news.getDateTime() 132 +"',content='"+news.getContent()+"' where id="+news.getId()+""; 133 System.out.println(sql); 134 Statement state=null; 135 try { 136 state = con.createStatement(); 137 int i=state.executeUpdate(sql); 138 System.out.println(i); 139 if(i>0) { 140 flag=true; 141 } 142 } catch (SQLException e) { 143 System.out.println("更新错误啦"); 144 e.printStackTrace(); 145 } 146 147 return false; 148 } 149 150 //删除 151 public boolean delete(int id) { 152 con=Newsdao.getCon(); 153 boolean flag=false; 154 String sql="delete from news where id='"+id+"'"; 155 // System.out.println(sql); 156 PreparedStatement ps; 157 try { 158 ps = con.prepareStatement(sql); 159 int i=ps.executeUpdate(); 160 if(i>0){ 161 flag=true; 162 } 163 } catch (SQLException e) { 164 System.out.println("删除出错啦"); 165 e.printStackTrace(); 166 } 167 168 return flag; 169 } 170 171 }
新闻的添加
package servlet; import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import bean.News; import dao.Newsdao; /** * Servlet implementation class AddServlet */ @WebServlet("/AddServlet") public class AddServlet extends HttpServlet { public AddServlet() { super(); } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request,response); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("utf-8"); response.setContentType("text/html;charset=UTF-8"); String title=request.getParameter("title"); String type=request.getParameter("type"); String datetime=request.getParameter("datetime"); String content=request.getParameter("ueditor"); System.out.println("这是ueditor的内容"+title+content); News news=new News(); news.setTitle(title); news.setContent(content); news.setDateTime(datetime); news.setType(type); Newsdao nd=new Newsdao(); try{ nd.addNews(news); response.sendRedirect("newslistServlet"); //request.getRequestDispatcher("/newslist.jsp").forward(request, response); }catch(Exception e) { System.out.println("添加失败"); } } }
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%> <%@page import="java.util.*" %> <%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%> <%@ taglib uri="http://java.sun.com/jsp/jstl/fmt" prefix="fmt" %> <!DOCTYPE html> <html> <head> <meta http-equiv="Content-Type" content="text/html" charset="utf-8"> <script type="text/javascript" charset="utf-8" src="utf8-jsp/ueditor.config.js"></script> <script type="text/javascript" charset="utf-8" src="utf8-jsp/ueditor.all.min.js"> </script> <script type="text/javascript" charset="utf-8" src="utf8-jsp/lang/zh-cn/zh-cn.js"></script> <title>新闻页</title> <style type="text/css"> body{ margin-top:20px; backgroud-color:#ff2812; text-align:center; } .text{ 500px; height:20px; } .btn{ right: 35px; bottom: 25px; 100px; height: 30px; background: #759fc7; font-size: 15px; color: #fff; letter-spacing: 10px; margin-left:40px; text-align: center; } </style> </head> <body> <div > <h2>添加新闻</h2> <form action="addServlet" method="POST" > 新闻标题 <input class="text" type="text" name="title" ><br><br> 新闻类别 <input type="radio" name="type" value="娱乐" checked="checked"/>娱乐 <input type="radio" name="type" value="体育"/>体育 <input type="radio" name="type" value="国际"/>国际 <input type="radio" name="type" value="社会"/>社会 <input type="radio" name="type" value="财经"/>财经 <input type="radio" name="type " value="科技"/>科技 <br><br> 发布时间 <input class="text" type="text" name="datetime" ><br><br> 正文编辑 <script id="editor" type="text/plain" name="ueditor" style="1024px;height:500px;margin-left:100px"></script> <button class="btn" type="submit">保存</button > <!-- <button class="btn" type="submit">退出</button> --> </form> </div> <script type="text/javascript"> var ue=UE.getEditor('editor'); function getPlainTxt() { var arr = []; arr.push("使用editor.getPlainTxt()方法可以获得编辑器的带格式的纯文本内容"); arr.push("内容为:"); arr.push(UE.getEditor('editor').getPlainTxt()); alert(arr.join(' ')) } </script> </body> </html>
删除
package servlet; import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import dao.Newsdao; /** * Servlet implementation class DeleteServlet */ @WebServlet("/DeleteServlet") public class DeleteServlet extends HttpServlet { private static final long serialVersionUID = 1L; public DeleteServlet() { super(); } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request,response); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("utf-8"); response.setContentType("text/html;charset=utf-8"); String id=(String)request.getParameter("id"); System.out.println("被删除的新闻"); int nid=Integer.parseInt(id); Newsdao nd=new Newsdao(); nd.delete(nid); response.sendRedirect("newslistServlet"); //request.getRequestDispatcher("/newslist.jsp").forward(request, response); } }
修改
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%> <%@page import="java.util.*" %> <%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%> <%@ taglib uri="http://java.sun.com/jsp/jstl/fmt" prefix="fmt" %> <!DOCTYPE html> <html> <head> <meta http-equiv="Content-Type" content="text/html" charset="utf-8"> <script type="text/javascript" charset="utf-8" src="utf8-jsp/ueditor.config.js"></script> <script type="text/javascript" charset="utf-8" src="utf8-jsp/ueditor.all.min.js"> </script> <script type="text/javascript" charset="utf-8" src="utf8-jsp/lang/zh-cn/zh-cn.js"></script> <title>新闻页</title> <style type="text/css"> body{ margin-top:20px; backgroud-color:#ff2812; text-align:center; } .text{ 500px; height:20px; } .btn{ right: 35px; bottom: 25px; 100px; height: 30px; background: #759fc7; font-size: 15px; color: #fff; letter-spacing: 10px; margin-left:40px; text-align: center; } </style> </head> <body> <div > <h2>修改新闻</h2> <form action="updateServlet" method="GET" > <c:forEach var="s" items="${item}"> 新闻编号 <input class="text" type="text" name="id" value="${s.id }"><br><br> 新闻标题 <input class="text" type="text" name="title" value="${s.title }"><br><br> 新闻类别 <input type="radio" name="type" value="娱乐" ${("娱乐"eq s.type)?"checked":""}/>娱乐 <input type="radio" name="type" value="体育" ${("体育"eq s.type)?"checked":""}/>体育 <input type="radio" name="type" value="国际" ${("国际"eq s.type)?"checked":""}/>国际 <input type="radio" name="type" value="社会" ${("社会"eq s.type)?"checked":""}/>社会 <input type="radio" name="type" value="财经" ${("财经"eq s.type)?"checked":""}/>财经 <input type="radio" name="type" value="科技" ${("科技"eq s.type)?"checked":""}/>科技 <br><br> 发布时间 <input class="text" type="text" name="datetime" value="${s.dateTime }" ><br><br> 正文编辑 <script id="editor" type="text/plain" name="editor" style="1024px;height:500px;margin-left:100px">${s.content}</script> <button class="btn" type="submit">保存</button > <!-- <button class="btn" type="submit">退出</button> --> </form> </div> </c:forEach> <script type="text/javascript"> var ue=UE.getEditor('editor'); UE.getEditor('editor').setContent('${s.content}'); /* function setContent(isAppendTo) { var arr = []; arr.push("使用editor.setContent('欢迎使用ueditor')方法可以设置编辑器的内容"); ue.getEditor('editor').setContent('欢迎使用ueditor', isAppendTo); alert(arr.join(" ")); } */ //alter("gg"); //UE.getEditor('editor').setContent('${s.content}'); function getContent() { var arr = []; arr.push(UE.getEditor('editor').getContent()); alert(arr.join(" ")); } </script> </body> </html>
package servlet; import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import bean.News; import dao.Newsdao; /** * Servlet implementation class UpnewsServlet */ @WebServlet("/UpdateServlet") public class UpdateServlet extends HttpServlet { private static final long serialVersionUID = 1L; public UpdateServlet() { super(); } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request,response); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html;charset=UTF-8"); request.setCharacterEncoding("utf-8"); String id=request.getParameter("id"); System.out.println("id的值为"+id); int nid=Integer.parseInt(id); String title=request.getParameter("title"); String type=request.getParameter("type"); String datetime=request.getParameter("datetime"); String content=request.getParameter("editor"); News news=new News(); news.setId(nid); news.setTitle(title); news.setContent(content); news.setDateTime(datetime); news.setType(type); Newsdao nd=new Newsdao(); try{ nd.update(news); response.sendRedirect("newslistServlet"); }catch(Exception e) { System.out.println("修改失败"); } } }
package servlet; import java.io.IOException; import java.util.List; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import bean.News; import dao.Newsdao; /** * Servlet implementation class ShowServlet */ @WebServlet("/ShowServlet") public class ShowServlet extends HttpServlet { private static final long serialVersionUID = 1L; public ShowServlet() { super(); } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request,response); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("utf-8"); response.setContentType("text/html;cahrset=utf-8"); String id=request.getParameter("id"); int nid=Integer.parseInt(id); Newsdao nd=new Newsdao(); List<News> list=nd.selectByID(nid); request.setAttribute("item", list); System.out.println(list.size()); request.getRequestDispatcher("/update.jsp").forward(request, response); } }
查找
package servlet; import java.io.IOException; import java.util.List; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import bean.News; import dao.Newsdao; @WebServlet("/SelectServlet") public class SelectServlet extends HttpServlet { private static final long serialVersionUID = 1L; public SelectServlet() { super(); } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request,response); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("utf-8"); response.setContentType("text/html;cahrset=utf-8"); String id=request.getParameter("id"); int nid=Integer.parseInt(id); Newsdao nd=new Newsdao(); List<News> list=nd.selectByID(nid); request.setAttribute("news", list); System.out.println(list.size()); request.getRequestDispatcher("/content.jsp").forward(request, response); } }