jsp+servlet实现最简单的增删改查代码分享
话不多说,请看代码
packageceet.ac.cn.dao; importjava.sql.Connection; importjava.sql.PreparedStatement; importjava.sql.ResultSet; importjava.sql.SQLException; importjava.util.ArrayList; importjava.util.List; importceet.ac.cn.model.Admin; publicclassAdminDao{ publicList<Admin>getAllAdmin(){//查询所有信息 List<Admin>list=newArrayList<Admin>();//创建集合 Connectionconn=DbHelper.getConnection(); Stringsql="select*fromadmin";//SQL查询语句 try{ PreparedStatementpst=conn.prepareStatement(sql); ResultSetrst=pst.executeQuery(); while(rst.next()){ Adminadmin=newAdmin(); admin.setId(rst.getInt("id"));//得到ID admin.setUsername(rst.getString("username")); admin.setUserpwd(rst.getString("userpwd")); list.add(admin); } rst.close();//关闭 pst.close();//关闭 }catch(SQLExceptione){ e.printStackTrace();//抛出异常 } returnlist;//返回一个集合 } publicbooleanaddAdmin(Adminadmin){//添加信息 Stringsql="INSERTINTO`admin`(`id`,`username`,`userpwd`)VALUES(?,?,?)";//添加的SQL语句 Connectionconn=DbHelper.getConnection(); try{ PreparedStatementpst=conn.prepareStatement(sql); pst.setInt(1,admin.getId()); pst.setString(2,admin.getUsername()); pst.setString(3,admin.getUserpwd()); intcount=pst.executeUpdate(); pst.close(); returncount>0?true:false;//是否添加的判断 }catch(SQLExceptione){ e.printStackTrace(); } returnfalse; } publicbooleanupdateAdmin(Adminadmin){//修改 Stringsql="UPDATE`admin`SET`username`=?,`userpwd`=?WHERE`id`=?";//修改的SQL语句,根据ID修改 Connectionconn=DbHelper.getConnection(); try{ PreparedStatementpst=conn.prepareStatement(sql); pst.setString(1,admin.getUsername()); pst.setString(2,admin.getUserpwd()); pst.setInt(3,admin.getId());//根据的ID intcount=pst.executeUpdate(); pst.close();//关闭 returncount>0?true:false;//是否修改的判断 }catch(SQLExceptione){ e.printStackTrace(); } returnfalse; } publicbooleandeleteAdmin(intid){//删除 Stringsql="deletefromadminwhereid=?";//删除的SQL语句,根据ID删除 Connectionconn=DbHelper.getConnection(); try{ PreparedStatementpst=conn.prepareStatement(sql); pst.setInt(1,id); intcount=pst.executeUpdate(); pst.close(); returncount>0?true:false;//是否删除的判断 }catch(SQLExceptione){ e.printStackTrace(); } returnfalse; } publicAdminselectAdminById(intid){//根据ID进行查询 Connectionconn=DbHelper.getConnection(); Stringsql="select*fromadminwhereid="+id; Adminadmin=null; try{ PreparedStatementpst=conn.prepareStatement(sql); ResultSetrst=pst.executeQuery(); while(rst.next()){ admin=newAdmin(); admin.setId(rst.getInt("id")); admin.setUsername(rst.getString("username")); admin.setUserpwd(rst.getString("userpwd")); } rst.close(); pst.close(); }catch(SQLExceptione){ e.printStackTrace(); } returnadmin;//返回 } }
packageceet.ac.cn.dao; importjava.sql.Connection; importjava.sql.DriverManager; /** *连接数据库 *@author画船听雨眠 * */ publicclassDbHelper{ privatestaticStringurl="jdbc:mysql://localhost:3306/admin";//数据库地址 privatestaticStringuserName="root";//数据库用户名 privatestaticStringpassWord="359129127";//数据库密码 privatestaticConnectionconn=null; privateDbHelper(){ } publicstaticConnectiongetConnection(){ if(null==conn){ try{ Class.forName("com.mysql.jdbc.Driver"); conn=DriverManager.getConnection(url,userName,passWord); }catch(Exceptione){ e.printStackTrace(); } } returnconn; } publicstaticvoidmain(String[]args){//测试数据库是否连通 System.err.println(getConnection()); } }
packageceet.ac.cn.model; importjava.io.Serializable; publicclassAdminimplementsSerializable{//数据封装类 privatestaticfinallongserialVersionUID=1L; privateintid; privateStringusername; privateStringuserpwd; publicintgetId(){ returnid; } publicvoidsetId(intid){ this.id=id; } publicStringgetUsername(){ returnusername; } publicvoidsetUsername(Stringusername){ this.username=username; } publicStringgetUserpwd(){ returnuserpwd; } publicvoidsetUserpwd(Stringuserpwd){ this.userpwd=userpwd; } }
packageceet.ac.cn.servlet; importjava.io.IOException; importjavax.servlet.ServletException; importjavax.servlet.http.HttpServlet; importjavax.servlet.http.HttpServletRequest; importjavax.servlet.http.HttpServletResponse; importceet.ac.cn.dao.AdminDao; importceet.ac.cn.model.Admin; publicclassAddServletextendsHttpServlet{//添加数据 privatestaticfinallongserialVersionUID=1L; protectedvoiddoGet(HttpServletRequestreq,HttpServletResponseresp) throwsServletException,IOException{ this.doPost(req,resp); } protectedvoiddoPost(HttpServletRequestreq,HttpServletResponseresp) throwsServletException,IOException{ Stringusername=req.getParameter("username"); Stringuserpwd=req.getParameter("userpwd"); Adminadmin=newAdmin(); admin.setUsername(newString(username.getBytes("ISO-8859-1"),"UTF-8"));//转值,中文需要转换为utf-8 admin.setUserpwd(newString(userpwd.getBytes("ISO-8859-1"),"UTF-8")); AdminDaodao=newAdminDao(); dao.addAdmin(admin); req.getRequestDispatcher("ShowServlet").forward(req,resp); } }
packageceet.ac.cn.servlet; importjava.io.IOException; importjavax.servlet.ServletException; importjavax.servlet.http.HttpServlet; importjavax.servlet.http.HttpServletRequest; importjavax.servlet.http.HttpServletResponse; importceet.ac.cn.dao.AdminDao; publicclassDeleteServletextendsHttpServlet{//删除数据 privatestaticfinallongserialVersionUID=1L; protectedvoiddoGet(HttpServletRequestreq,HttpServletResponseresp) throwsServletException,IOException{ this.doPost(req,resp); } protectedvoiddoPost(HttpServletRequestreq,HttpServletResponseresp) throwsServletException,IOException{ StringidStr=req.getParameter("id");//删除数据的ID,根据ID删除 if(idStr!=null&&!idStr.equals("")){ intid=Integer.valueOf(idStr); AdminDaodao=newAdminDao(); dao.deleteAdmin(id); } req.getRequestDispatcher("ShowServlet").forward(req,resp); } }
packageceet.ac.cn.servlet; importjava.io.IOException; importjava.util.List; importjavax.servlet.ServletException; importjavax.servlet.http.HttpServlet; importjavax.servlet.http.HttpServletRequest; importjavax.servlet.http.HttpServletResponse; importceet.ac.cn.dao.AdminDao; importceet.ac.cn.model.Admin; publicclassShowServletextendsHttpServlet{//显示全部数据 privatestaticfinallongserialVersionUID=1L; protectedvoiddoGet(HttpServletRequestreq,HttpServletResponseresp) throwsServletException,IOException{ this.doPost(req,resp); } protectedvoiddoPost(HttpServletRequestreq,HttpServletResponseresp) throwsServletException,IOException{ AdminDaodao=newAdminDao(); List<Admin>list=dao.getAllAdmin(); req.setAttribute("list",list); req.getRequestDispatcher("index.jsp").forward(req,resp); } }
packageceet.ac.cn.servlet; importjava.io.IOException; importjavax.servlet.ServletException; importjavax.servlet.http.HttpServlet; importjavax.servlet.http.HttpServletRequest; importjavax.servlet.http.HttpServletResponse; importceet.ac.cn.dao.AdminDao; importceet.ac.cn.model.Admin; publicclassUpdateServletextendsHttpServlet{//修改 privatestaticfinallongserialVersionUID=1L; protectedvoiddoGet(HttpServletRequestreq,HttpServletResponseresp) throwsServletException,IOException{//查询到选中ID的值所对应的数据 StringidStr=req.getParameter("id"); if(idStr!=null&&!idStr.equals("")){ intid=Integer.valueOf(idStr); AdminDaodao=newAdminDao(); Adminadmin=dao.selectAdminById(id); req.setAttribute("admin",admin); } req.getRequestDispatcher("update.jsp").forward(req,resp); } protectedvoiddoPost(HttpServletRequestreq,HttpServletResponseresp) throwsServletException,IOException{//根据此ID对数据的值进行修改 Stringusername=req.getParameter("username"); Stringuserpwd=req.getParameter("userpwd"); StringidStr=req.getParameter("id"); Adminadmin=newAdmin(); admin.setId(Integer.valueOf(idStr)); admin.setUsername(newString(username.getBytes("ISO-8859-1"),"UTF-8")); admin.setUserpwd(newString(userpwd.getBytes("ISO-8859-1"),"UTF-8")); AdminDaodao=newAdminDao(); dao.updateAdmin(admin); req.getRequestDispatcher("ShowServlet").forward(req,resp); } }
<%@pagelanguage="java"import="java.util.*"pageEncoding="UTF-8"%> <!DOCTYPEHTMLPUBLIC"-//W3C//DTDHTML4.01Transitional//EN"> <html> <head> <title>添加</title> <linkrel="stylesheet"href="css/index.css"type="text/css"/> </head> <body> <formaction="AddServlet"method="post"> <tableborder="1"class="t1"> <tr> <tdcolspan="2"><h1>添加管理员</h1></td> </tr> <tr> <td>管理员帐号:</td> <td><inputtype="text"name="username"/></td> </tr> <tr> <td>管理员密码:</td> <td><inputtype="password"name="userpwd"/></td> </tr> <tr> <tdcolspan="2"> <inputtype="submit"value="提交"/> <inputtype="reset"value="清空"/> </td> </tr> </table> </form> </body> </html>
<%@pagelanguage="java"contentType="text/html;charset=utf-8" pageEncoding="utf-8"%> <%@taglibprefix="c"uri="http://java.sun.com/jsp/jstl/core"%> <!DOCTYPEhtmlPUBLIC"-//W3C//DTDHTML4.01Transitional//EN""http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <metahttp-equiv="Content-Type"content="text/html;charset=utf-8"> <title>显示</title> <styletype="text/css"> table{ border:1pxsolidpink; margin:0auto; } td{ width:150px; border:1pxsolidpink; text-align:center; } </style> </head> <body> <table> <tr> <td>编号</td> <td>帐号</td> <td>密码</td> <td>操作</td> </tr> <c:forEachitems="${list}"var="item"> <tr> <td>${item.id}</td> <td>${item.username}</td> <td>${item.userpwd}</td> <td><ahref="DeleteServlet?id=${item.id}">删除</a>|<ahref="UpdateServlet?id=${item.id}">修改</a></td> </tr> </c:forEach> <tr> <tdcolspan="6"style="text-align:left;"><ahref="add.jsp">添加管理员</a></td> </tr> </table> </body> </html>
<%@pagelanguage="java"import="java.util.*"pageEncoding="UTF-8"%> <!DOCTYPEHTMLPUBLIC"-//W3C//DTDHTML4.01Transitional//EN"> <html> <head> <title>修改</title> <linkrel="stylesheet"href="css/index.css"type="text/css"/> </head> <body> <formaction="UpdateServlet"method="post"> <tableborder="1"class="t1"> <tr> <tdcolspan="2"><h1>修改管理员信息</h1></td> </tr> <tr> <td>编号:</td> <td><inputtype="text"name="id"value="${admin.id}"readonly="readonly"/></td> </tr> <tr> <td>管理员帐号:</td> <td><inputtype="text"name="username"value="${admin.username}"/></td> </tr> <tr> <td>管理员密码:</td> <td><inputtype="text"name="userpwd"value="${admin.userpwd}"/></td> </tr> <tr> <tdcolspan="2"> <inputtype="submit"value="提交"/> <inputtype="button"value="返回"onclick="history.go(-1)"/> </td> </tr> </table> </form> </body> </html>
@CHARSET"UTF-8"; table.t1{ margin-top:10px; margin-left:20px; margin-right:20px; margin-bottom:5px; #background-color:#FFF; #background:#EEF4F9; #border:none; border:1; #color:#003755; border-collapse:collapse; font:14px"宋体"; text-align:center; } table.t1th{ background:#7CB8E2; color:#fff; padding:6px4px; text-align:center; } table.t1td{ background:#C7DDEEnonerepeat-xscrollcenterleft; color:#000; padding:4px2px; } table.t1a{ text-decoration:none; height:1em; } table.t1a:link,table.t1a:visited{ color:#3366CC; } table.t1a:hover{ color:#B50000; text-decoration:underline; }
最简单的jsp+servlet的增删改查代码。写的很清楚,就这样了。
实现原理:
每行数据后面加一个编辑和删除按钮,按钮提交到后台并且带有此行数据的主要参数。
点击编辑按钮,通过servlet操作jsp将此行的每一列替换为一个文本框并把已有的值带进去,后面一个提交按钮通过submit提交数据并将文本框重新变为表格的单元格。
新增,就像编辑一样,添加一行,全部是文本框。。。
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