Java之從頭開始編寫簡單課程信息管理系統
編寫簡單的課程管理系統對於新手並不友好,想要出色的完成並不容易以下是我的一些經驗和方法
詳情可參考以下鏈接:
https://www.cnblogs.com/dream0-0/p/10090828.html
一、相關的軟件下載和環境配置
1、下載並配置JDK。
2、下載eclipse。
3、下載並配置apache-tomcat(服務器)。
4、下載MySQL(數據庫)。
5、下載Navicat for MySQL(數據庫可視化工具),方便對數據庫的操作。
6、下載jdbc用來實現eclipse中的項目與數據庫實現連接。
二、代碼
在 WebContent 文件夾下,新建如下圖中的JSP文件,Login.jsp和signinerror.jsp是用來登陸的,這裏不必建立。
(1)head.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title></title> <style type="text/css"> .headdiv{ background-color:#3F51B5; width:100%; height:130px; } .headdiv P{ font-family:YouYuan; font-size:20px; color:#E8EAF6; position:relative; left:20px; top:45px; } </style> </head> <body> <div class="headdiv"> <p>ec-web課程信息綜合管理平臺</p> </div> </body> </html>
(2)left.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title></title> <style type="text/css"> .leftMenu{ background-color:#7986CB; width:250px; height:600px; position:relative; top:0px; } .menuParent{ background-color:#BBDEFB; } </style> </head> <body> <div class="leftMenu"> <div class="menu"> <div class="menuParent"> <div class="ListTitlePanel"> <div class="ListTitle"> <strong>課程信息管理</strong> <div class="leftbgbt"></div> </div> </div> <div class="menuList"> <div><a target="mainAction" href="USEJSP/add.jsp">課程信息錄入</a></div> <div><a target="mainAction" href="USEJSP/update.jsp">課程信息修改</a></div> <div><a target="mainAction" href="USEJSP/delete.jsp">刪除課程信息</a></div> <div><a target="mainAction" href="USEJSP/search.jsp">查詢課程信息</a></div> </div> </div> </div> </div> <script type="text/javascript"> </script> </body> </html>
(3)index.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title></title> </head> <body> 這是小主頁 </body> </html>
(4)main.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>課程信息管理系統</title> <style type="text/css"> .headframe{ width:100%; height:130px; border:0; } .leftframe{ float:left; width:250px; height:600px; border:0; } .mainframe{ float:right; width:1200px; height:600px; border:0; } </style> </head> <iframe src="head.jsp" class="headframe" scrolling="no"></iframe> <iframe src="left.jsp" class="leftframe" scrolling="no"></iframe> <iframe src="index.jsp" name="mainAction" class="mainframe"></iframe> </html>
在WebContent文件夾下建立名為USEJSP的文件夾,在USEJSP文件夾下,建立如下圖的JSP文件
(1)add.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title></title> <style type="text/css"> .butn{ display:inline-block; padding: 8px 35px; background-color:#32CD32; color:white; border:none; text-align:center; text-decoration:none; border-radius:5px; position:absolute; left:40px; top:95px; } </style> </head> <body> <div class="container"> <section> <form action="${pageContext.request.contextPath}/AddServlet/AddCurrServlet?method=add" method="post" onsubmit="return check()"> <!---${pageContext.request.contextPath}的目的是找到主工程的名字,/Servlet/Userservlet就是web.xml下面配置的路徑,也就是servlet的路徑---> <span class="cname">課程名稱</span> <input type="text" name="cname" class="icname" placeholder=" class-name" id="icname"> <br/> <span class="teacher">任課教師</span> <input type="text" name="teacher" class="iteacher" placeholder=" teacher" id="iteacher"> <br/> <span class="place">上課地點</span> <input type="text" name="place" class="iplace" placeholder=" place" id="iplace"> <br/> <input type="submit" value="保 存" class="butn"> <br/> </form> </section> </div> <script type="text/javascript"> function check() { var cname = document.getElementById("icname"); var teacher = document.getElementById("iteacher"); var place = document.getElementById("iplace"); var placestr = place.value.substring(0,2); //非空 if(cname.value == ‘‘) { alert(‘課程名稱為空‘); cname.focus(); return false; } if(teacher.value == ‘‘) { alert(‘教師為空‘); teacher.focus(); return false; } if(place.value == ‘‘) { alert(‘上課地點為空‘); place.focus(); return false; } //教師 if(teacher.value != ‘王建民‘ && teacher.value != ‘王輝‘ && teacher.value != ‘劉丹‘ && teacher.value != ‘劉立嘉‘ && teacher.value != ‘楊子光‘){ alert(‘教師名稱錯誤‘); return false; } //教室 if(!/^基教/.test(placestr) && !/^一教/.test(placestr) && !/^二教/.test(placestr) && !/^三教/.test(placestr)) { alert(‘上課地點錯誤‘); return false; } return true; } </script> </body> </html>
(2)addnameerror.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title></title> <style type="text/css"> .butn{ display:inline-block; padding: 8px 35px; background-color:#32CD32; color:white; border:none; text-align:center; text-decoration:none; border-radius:5px; position:absolute; left:40px; top:95px; } </style> </head> <body onload="alt()"> <div class="container"> <section> <form action="${pageContext.request.contextPath}/AddServlet/AddCurrServlet?method=add" method="post" onsubmit="return check()"> <!---${pageContext.request.contextPath}的目的是找到主工程的名字,/Servlet/Userservlet就是web.xml下面配置的路徑,也就是servlet的路徑---> <span class="cname">課程名稱</span> <input type="text" name="cname" class="icname" placeholder=" class-name" id="icname"> <br/> <span class="teacher">任課教師</span> <input type="text" name="teacher" class="iteacher" placeholder=" teacher" id="iteacher"> <br/> <span class="place">上課地點</span> <input type="text" name="place" class="iplace" placeholder=" place" id="iplace"> <br/> <input type="submit" value="保 存" class="butn"> <br/> </form> </section> </div> <script type="text/javascript"> function check() { var cname = document.getElementById("icname"); var teacher = document.getElementById("iteacher"); var place = document.getElementById("iplace"); var placestr = place.value.substring(0,2); //非空 if(cname.value == ‘‘) { alert(‘課程名稱為空‘); cname.focus(); return false; } if(teacher.value == ‘‘) { alert(‘教師為空‘); teacher.focus(); return false; } if(place.value == ‘‘) { alert(‘上課地點為空‘); place.focus(); return false; } //教師 if(teacher.value != ‘王建民‘ && teacher.value != ‘王輝‘ && teacher.value != ‘劉丹‘ && teacher.value != ‘劉立嘉‘ && teacher.value != ‘楊子光‘){ alert(‘教師名稱錯誤‘); return false; } //教室 if(!/^基教/.test(placestr) && !/^一教/.test(placestr) && !/^二教/.test(placestr) && !/^三教/.test(placestr)) { alert(‘上課地點錯誤‘); return false; } return true; } function alt() { alert(‘課程名稱重復‘); } </script> </body> </html>
(3)delete.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html> <%@page import="java.sql.*"%> <%@page import="java.sql.Connection"%> <%@page import="java.sql.Statement"%> <%@page import="java.sql.ResultSet"%> <%@page import="java.sql.DriverManager"%> <%@page import="javax.servlet.http.HttpServletRequest"%> <html> <head> <meta charset="UTF-8"> <title></title> <style type="text/css"> .butn{ display:inline-block; padding: 8px 35px; background-color:#32CD32; color:white; border:none; text-align:center; text-decoration:none; border-radius:5px; position:absolute; left:40px; top:95px; } </style> </head> <body> <div> <section> <form action="${pageContext.request.contextPath}/DeleteServlet/DeleteCurrServlet?method=add" method="post" onsubmit="return check()"> <span class="cname">課程名稱</span> <input type="text" name="cname" id="icname" class="icname" placeholder=" class-name"> <br/> <input type="submit" value="刪除" class="butn"> <br/> </form> </section> </div> <script type="text/javascript"> function check() { var cname = document.getElementById("icname"); //非空 if(cname.value == ‘‘) { alert(‘課程名稱為空,請重新輸入‘); cname.focus(); return false; } return true; } </script> </body> </html>
(4)search.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html> <%@page import="java.sql.*"%> <%@page import="java.sql.Connection"%> <%@page import="java.sql.Statement"%> <%@page import="java.sql.ResultSet"%> <%@page import="java.sql.DriverManager"%> <%@page import="javax.servlet.http.HttpServletRequest"%> <html> <head> <meta charset="UTF-8"> <title></title> <style type="text/css"> .butn{ display:inline-block; padding: 8px 35px; background-color:#32CD32; color:white; border:none; text-align:center; text-decoration:none; border-radius:5px; position:absolute; left:40px; top:95px; } </style> </head> <body> <div> <section> <form action="${pageContext.request.contextPath}/SearchServlet/SearchCurrServlet?method=add" method="post"> <span class="cname">課程名稱</span> <input type="text" name="cname" id="cname" class="icname" placeholder=" class-name"> <br/> <span class="teacher">任課教師</span> <input type="text" name="teacher" id="teacher" class="iteacher" placeholder=" teacher"> <br/> <span class="place">上課地點</span> <input type="text" name="place" id="place" class="iplace" placeholder=" place"> <br/> <input type="submit" value="查詢" class="butn"> <br/> </form> </section> </div> </body> </html>
(5)update.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html> <%@page import="java.sql.*"%> <%@page import="java.sql.Connection"%> <%@page import="java.sql.Statement"%> <%@page import="java.sql.ResultSet"%> <%@page import="java.sql.DriverManager"%> <html> <head> <meta charset="UTF-8"> <title></title> </head> <body> <form action="${pageContext.request.contextPath}/UpdateServlet/UpdateCurrServlet?method=update" method="post" onsubmit="return check()"> <span class="cname">需要修改的課程名稱</span> <input type="text" name="tempcname" class="itempcname" placeholder=" class-name" id="itempcname"> <br/> <table border="1" bgcolor="#ffffff" align="" cellspacing="1" cellpadding="1"> <caption>輸入修改信息</caption> <tr> <td align="center" width=16%>新課程名稱</td> <td align="center" width=16%>新任課教師</td> <td align="center" width=25%>新上課地點</td> <td align="center" width=16%>操作</td> </tr> <tr> <td width=16% align="center"><input type="text" name="cname" class="icname" placeholder=" class-name" id="icname"></td> <td width=16% align="center"><input type="text" name="teacher" class="iteacher" placeholder=" teacher" id="iteacher"></td> <td width=25% align="center"><input type="text" name="place" class="iplace" placeholder=" place" id="iplace"></td> <td width=16% align="center"><input type="submit" value="修 改" class="butn"></td> </tr> </table> </form> </body> <script type="text/javascript"> function check() { var ctempname = document.getElementById("itempcname"); var cname = document.getElementById("icname"); var teacher = document.getElementById("iteacher"); var place = document.getElementById("iplace"); var placestr = place.value.substring(0,2); //非空 if(ctempname.value == ‘‘){ alert(‘需修改課程名稱為空‘); teacher.focus(); return false; } if(cname.value == ‘‘) { alert(‘課程名稱為空‘); cname.focus(); return false; } if(teacher.value == ‘‘) { alert(‘教師為空‘); teacher.focus(); return false; } if(place.value == ‘‘) { alert(‘上課地點為空‘); place.focus(); return false; } //教師 if(teacher.value != ‘王建民‘ && teacher.value != ‘王輝‘ && teacher.value != ‘劉丹‘ && teacher.value != ‘劉立嘉‘ && teacher.value != ‘楊子光‘){ alert(‘教師名稱錯誤‘); return false; } //教室 if(!/^基教/.test(placestr) && !/^一教/.test(placestr) && !/^二教/.test(placestr) && !/^三教/.test(placestr)) { alert(‘上課地點錯誤‘); return false; } return true; } </script> </html>
下面,生成web.xml文件(用來配置跳轉路徑)
在你的項目上右擊,java EE Tool—》Generate Deployment Descriptor Stub
這樣,在WebContent/WEB-INF文件夾下就生成了.xml文件,如下圖
(1)Web.xml
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" version="3.0"> <display-name>curriculum_information_management_web</display-name> <welcome-file-list> <welcome-file>index.html</welcome-file> <welcome-file>index.htm</welcome-file> <welcome-file>index.jsp</welcome-file> <welcome-file>default.html</welcome-file> <welcome-file>default.htm</welcome-file> <welcome-file>default.jsp</welcome-file> </welcome-file-list> <servlet> <servlet-name>Userservlet</servlet-name> <!--servlet的別名,隨便取 --> <!--servlet的包路徑,後面再加上.servlet類名 ,這裏的類名必須是包下面的servlet類名,目的是讓找到該servlet的路徑 --> <servlet-class>com.Servlet.Userservlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>Userservlet</servlet-name> <!--servlet的別名,和上面保持一致就行 --> <!--jsp跳轉到servlet的路徑名,自己取,用來從jsp界面跳轉到servlet的路徑,程序會根據路徑找到servlet的位置 --> <url-pattern>/Servlet/Userservlet</url-pattern><!-- --> </servlet-mapping> <servlet> <servlet-name>AddCurrServlet</servlet-name> <servlet-class>com.Servlet.AddCurrServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>AddCurrServlet</servlet-name> <url-pattern>/AddServlet/AddCurrServlet</url-pattern><!-- --> </servlet-mapping> <servlet> <servlet-name>SearchCurrServlet</servlet-name> <servlet-class>com.Servlet.SearchCurrServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>SearchCurrServlet</servlet-name> <url-pattern>/SearchServlet/SearchCurrServlet</url-pattern><!-- --> </servlet-mapping> <servlet> <servlet-name>DeleteCurrServlet</servlet-name> <servlet-class>com.Servlet.DeleteCurrServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>DeleteCurrServlet</servlet-name> <url-pattern>/DeleteServlet/DeleteCurrServlet</url-pattern><!-- --> </servlet-mapping> <servlet> <servlet-name>UpdateCurrServlet</servlet-name> <servlet-class>com.Servlet.UpdateCurrServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>UpdateCurrServlet</servlet-name> <url-pattern>/UpdateServlet/UpdateCurrServlet</url-pattern><!-- --> </servlet-mapping> </web-app>
在項目下的 Java Resources/src 建立包,如下圖
然後,在各包下建立類,如圖
(1)com.Bean
package com.Bean; public class CurrBean { private String name; private String teacher; private String place; public String getName() { return name; } public void setName(String name) { this.name = name; } public String getTeacher() { return teacher; } public void setTeacher(String teacher) { this.teacher = teacher; } public String getPlace() { return place; } public void setPlace(String place) { this.place = place; } }
(2)com.Dao(該包中的類是用來登錄操作的,在這裏只是寫出來,不用實現)
package com.Dao; import java.sql.Connection; import java.sql.ResultSet; import java.sql.Statement; import com.DBUtil.*; public class Userdao { public int login(String username,String password) { Connection conn = DBUtil.getConn();//這裏就是從DBUtil類裏面得到連接 Statement state =null; ResultSet rs = null; int flag=0; try { String sql = "select * from admin";//SQL語句 state = conn.createStatement(); rs=state.executeQuery(sql); while(rs.next()) { if(rs.getString("password").equals(password)&&rs.getString("username").equals(username)) { flag=1; } } } catch(Exception e) { e.printStackTrace(); } finally { DBUtil.close(rs, state, conn); } return flag; } }
(3)com.DBUtil建立CurrDBUtil.java文件(鏈接數據庫)
package com.DBUtil; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; public class CurrDBUtil { public static String db_url="jdbc:mysql://localhost:3306/curriculum?useSSL=true&serverTimezone=UTC"; //這是連接數據庫,userdome是數據庫的名稱,userUnicode=true&characterEncoding=UTF-8是將字符集設置為utf-8,避免亂碼。 public static String db_user="root";//數據的用戶名 public static String db_password="lty";//數據庫的密碼 public static Connection getConn()//獲取連接,返回Connection類型,必須設置為static這樣才能在其他類中使用 { Connection conn=null; try { Class.forName("com.mysql.jdbc.Driver");//加載驅動 conn=DriverManager.getConnection(db_url,db_user,db_password);//連接數據庫 } catch(Exception e) { e.printStackTrace(); } return conn; } public static void close(Statement state,Connection conn)//關閉函數 { if(state!=null)//只有狀態和連接時,先關閉狀態 { try { state.close(); } catch(SQLException e) { e.printStackTrace(); } } if(conn!=null) { try { conn.close(); } catch(SQLException e) { e.printStackTrace(); } } } public static void close(ResultSet rs,Statement state,Connection conn) { if(rs!=null)//有結果集,狀態和連接時,先關閉結果集,在關閉狀態,在關閉連接 { try { rs.close(); } catch(SQLException e) { e.printStackTrace(); } } if(state!=null) { try { state.close(); } catch(SQLException e) { e.printStackTrace(); } } if(conn!=null) { try { conn.close(); } catch(SQLException e) { e.printStackTrace(); } } } }
建立DBUtil.java文件(用來鏈接登錄數據庫,不必實現)
package com.DBUtil; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; public class DBUtil { public static String db_url="jdbc:mysql://localhost:3306/userdome?useSSL=true&serverTimezone=UTC"; //這是連接數據庫,userdome是數據庫的名稱,userUnicode=true&characterEncoding=UTF-8是將字符集設置為utf-8,避免亂碼。 public static String db_user="root";//數據的用戶名 public static String db_password="lty100609";//數據庫的密碼 public static Connection getConn()//獲取連接,返回Connection類型,必須設置為static這樣才能在其他類中使用 { Connection conn=null; try { Class.forName("com.mysql.jdbc.Driver");//加載驅動 conn=DriverManager.getConnection(db_url,db_user,db_password);//連接數據庫 } catch(Exception e) { e.printStackTrace(); } return conn; } public static void close(Statement state,Connection conn)//關閉函數 { if(state!=null)//只有狀態和連接時,先關閉狀態 { try { state.close(); } catch(SQLException e) { e.printStackTrace(); } } if(conn!=null) { try { conn.close(); } catch(SQLException e) { e.printStackTrace(); } } } public static void close(ResultSet rs,Statement state,Connection conn) { if(rs!=null)//有結果集,狀態和連接時,先關閉結果集,在關閉狀態,在關閉連接 { try { rs.close(); } catch(SQLException e) { e.printStackTrace(); } } if(state!=null) { try { state.close(); } catch(SQLException e) { e.printStackTrace(); } } if(conn!=null) { try { conn.close(); } catch(SQLException e) { e.printStackTrace(); } } } }
(4)com.Servlet
AddCurrServlet.java 實現課程的增加
package com.Servlet; import java.io.IOException; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import com.Bean.CurrBean; import com.DBUtil.*; public class AddCurrServlet extends HttpServlet { private static final long serialVersionUID = 1L; protected void doPost(HttpServletRequest req,HttpServletResponse resp)throws ServletException,IOException{ resp.setContentType("add.jsp"); req.setCharacterEncoding("UTF-8"); String name; String teacher; String place; name = req.getParameter("cname"); teacher = req.getParameter("teacher"); place = req.getParameter("place"); CurrBean currbean = new CurrBean(); currbean.setName(name); currbean.setTeacher(teacher); currbean.setPlace(place); AddCurrInterface addCurrInterface = new AddCurrInterface(); @SuppressWarnings("unused") int temp = 0; try { temp = addCurrInterface.addUser(currbean); if(temp == 1) { resp.sendRedirect(req.getContextPath()+"/index.jsp"); }else if(temp == 2) { resp.sendRedirect(req.getContextPath()+"/USEJSP/addnameerror.jsp"); } } catch (SQLException e) { e.printStackTrace(); } } } class AddCurrInterface extends HttpServlet{ private static final long serialVersionUID = 1L; public int addUser(CurrBean cb) throws SQLException { String name; String teacher; String place; name = cb.getName(); teacher = cb.getTeacher(); place = cb.getPlace(); //連接數據庫 Connection conn = CurrDBUtil.getConn(); PreparedStatement pstmt = null; Statement stmt = conn.createStatement(); String selectsql = "select * from curr_info"; ResultSet rs = stmt.executeQuery(selectsql); int tt = 0; while(rs.next()) { if(rs.getString("name").equals(name)) { tt = 2; } } if(tt == 0) { String sql = "insert into curr_info (name,teacher,place) values (?,?,?)";//數據庫指令 pstmt = conn.prepareStatement(sql);//發送sql語句 //下面是插入到具體的地方 pstmt.setString(1, name); pstmt.setString(2, teacher); pstmt.setString(3, place); pstmt.executeUpdate(); System.out.println("添加成功!"); return 1; }else if(tt == 2) { return 2; } return 0; } }
DeleteCurrServlet.java 實現課程的刪除
package com.Servlet; import java.io.BufferedWriter; import java.io.IOException; import java.io.OutputStream; import java.io.OutputStreamWriter; import java.io.PrintWriter; import java.sql.Connection; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import com.DBUtil.CurrDBUtil; public class DeleteCurrServlet extends HttpServlet { private static final long serialVersionUID = 1L; protected void doPost(HttpServletRequest req,HttpServletResponse resp)throws ServletException,IOException{ resp.setContentType("delete.jsp"); req.setCharacterEncoding("UTF-8"); String name; @SuppressWarnings("unused") int ii = 0; name = req.getParameter("cname"); //連接數據庫 Connection conn = CurrDBUtil.getConn(); try { Statement stmt = conn.createStatement(); String selectsql = "select * from curr_info"; ResultSet rs = stmt.executeQuery(selectsql); while(rs.next()) { if(rs.getString("name").equals(name)) { ii = rs.getInt("id"); //Get output stream and writers OutputStream out=resp.getOutputStream(); PrintWriter pw=new PrintWriter(new BufferedWriter(new OutputStreamWriter(out))); //Print HTML pw.println("<HTML><HEAD><TITLE>輸出HTML標簽</HEAD></TITLE><BODY>"); pw.println("<table border=\"1\" bgcolor=\"#ffffff\" align=\"\" cellspacing=\"1\" cellpadding=\"1\">"); pw.println("<tr>\r\n" + "<td align=\"center\" width=16%>課程名稱</td>\r\n" + "<td align=\"center\" width=16%>任課教師</td>\r\n" + "<td align=\"center\" width=35%>上課地點</td>\r\n" + "</tr>"); pw.println("<tr>\r\n" + "<td width=16% align=\"center\">"+rs.getString("name")+"</td>\r\n" + "<td width=16% align=\"center\">"+rs.getString("teacher")+"</td>\r\n" + "<td width=35% align=\"center\">"+rs.getString("place")+"</td>\r\n" + "</tr>"); pw.println("該課程已刪除!"); pw.println("</BODY></HTML>"); pw.flush(); pw.close(); } } String delesql="delete from curr_info where name=‘"+name+"‘ ";//生成一條sql語句 stmt.executeUpdate(delesql);//執行sql語句 } catch (SQLException e) { e.printStackTrace(); } } }
SearchCurrServlet.java 實現課程的查詢
package com.Servlet; import java.io.BufferedWriter; import java.io.IOException; import java.io.OutputStream; import java.io.OutputStreamWriter; import java.io.PrintWriter; import java.sql.Connection; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import com.DBUtil.CurrDBUtil; public class SearchCurrServlet extends HttpServlet { private static final long serialVersionUID = 1L; protected void doPost(HttpServletRequest req,HttpServletResponse resp)throws ServletException,IOException{ resp.setContentType("search.jsp"); req.setCharacterEncoding("UTF-8"); String name; String teacher; String place; name = req.getParameter("cname"); teacher = req.getParameter("teacher"); place = req.getParameter("place"); int temp = 0; //連接數據庫 Connection conn = CurrDBUtil.getConn(); try { Statement stmt = conn.createStatement(); String selectsql = "select * from curr_info"; ResultSet rs = stmt.executeQuery(selectsql); //Get output stream and writers OutputStream out=resp.getOutputStream(); PrintWriter pw=new PrintWriter(new BufferedWriter(new OutputStreamWriter(out))); //Print HTML pw.println("<HTML><HEAD><TITLE>輸出HTML標簽</HEAD></TITLE><BODY>"); pw.println("<table border=\"1\" bgcolor=\"#ffffff\" align=\"\" cellspacing=\"1\" cellpadding=\"1\">"); pw.println("<tr>\r\n" + "<td align=\"center\" width=16%>課程名稱</td>\r\n" + "<td align=\"center\" width=16%>任課教師</td>\r\n" + "<td align=\"center\" width=35%>上課地點</td>\r\n" + "</tr>"); while(rs.next()) { if(rs.getString("name").equals(name) || rs.getString("teacher").equals(teacher) || rs.getString("place").equals(place)) { pw.println("<tr>\r\n" + "<td width=16% align=\"center\">"+rs.getString("name")+"</td>\r\n" + "<td width=16% align=\"center\">"+rs.getString("teacher")+"</td>\r\n" + "<td width=35% align=\"center\">"+rs.getString("place")+"</td>\r\n" + "</tr>"); temp++; } /* else { //Get output stream and writers OutputStream out=resp.getOutputStream(); PrintWriter pw=new PrintWriter(new BufferedWriter(new OutputStreamWriter(out))); //Print HTML pw.println("<HTML><HEAD><TITLE>輸出HTML標簽</HEAD></TITLE><BODY>"); pw.println("查詢錯誤!"); pw.println("</BODY></HTML>"); pw.flush(); pw.close(); } */ } if(temp == 0) { pw.println("查詢錯誤!"); } pw.println("</BODY></HTML>"); pw.flush(); pw.close(); } catch (SQLException e) { e.printStackTrace(); } } }
UpdateCurrServlet.java 實現課程的修改
package com.Servlet; import java.io.IOException; import java.sql.Connection; import java.sql.SQLException; import java.sql.Statement; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import com.DBUtil.CurrDBUtil; public class UpdateCurrServlet extends HttpServlet { private static final long serialVersionUID = 1L; protected void doPost(HttpServletRequest req,HttpServletResponse resp)throws ServletException,IOException{ resp.setContentType("update.jsp"); req.setCharacterEncoding("UTF-8"); String tempname; String name; String teacher; String place; tempname = req.getParameter("tempcname"); name = req.getParameter("cname"); teacher = req.getParameter("teacher"); place = req.getParameter("place"); //連接數據庫 Connection conn = CurrDBUtil.getConn(); try { Statement stmt = conn.createStatement(); String updatesql = "update curr_info set name=‘"+name+"‘,teacher=‘"+teacher+"‘,place=‘"+place+"‘ where name=‘"+tempname+"‘"; stmt.executeUpdate(updatesql);//執行sql語句 resp.sendRedirect(req.getContextPath()+"/index.jsp"); } catch (SQLException e) { e.printStackTrace(); } } }
Java之從頭開始編寫簡單課程信息管理系統