菜鸟学编程第四式——Java编程环境搭建及实例图解3-优快云博客

本文链接：https://blog.youkuaiyun.com/skysandy/article/details/5524131

本文介绍了一个基于Java的Web应用程序实现用户数据增删改查的功能。通过展示具体的JSP页面代码，详细解释了如何使用JSP和JavaBean进行用户数据的显示、添加、编辑及删除操作。

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2.2.3编程

1、显示用户

show. jsp内容如下：

<%@ page import="robin.model.*" %> <jsp:useBean id="user_show" scope="page" class="robin.web.userdao" /> <%@ page language="java" contentType="text/html; charset=gb2312" %> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=gb2312"> <title>Robin JAVA Example</title> </head> <body> <h2>Show Data from DUser</h2> <table width="90%" border="1" align="center"> <tr> <td align="center" bgcolor="#00FFFF">UserId</td> <td align="center" bgcolor="#00FFFF">UserName</td> <td align="center" bgcolor="#00FFFF">UserPsd</td> <td align="center" bgcolor="#00FFFF">UserDetail</td> <td align="center" bgcolor="#00FFFF">编辑操作</td> <td align="center" bgcolor="#00FFFF">删除操作</td> </tr> <% if (user_show.execute()) { if (user_show.getUserList().size()>0 ){ for (int i=0;i<user_show.getUserList().size();i++){ userunit auser = (userunit) user_show.getUserList().elementAt(i);%> <tr> <td><%= auser.getUserId() %></td> <td><%= auser.getUserName() %></td> <td><%= auser.getUserPsd() %></td> <td><%= auser.getUserDetail() %></td> <td><a href="edit.jsp?UserId=<%= auser.getUserId() %>" >编辑</a></td> <td><a href="del.jsp?UserId=<%= auser.getUserId() %>" >删除</a></td> </tr> <% } }else { out.println("<tr><td align='center' colspan=6>No data.</td></tr>") ; } } else {%> <tr> <td align="center" colspan=6>Problem connecting to DataBase</td> </tr> <% } %> </table> <br /> <table width=90% align=center> <tr> <td><a href="add.jsp" mce_href="add.jsp">添加用户</a></td> </tr> </table> </body> </html>

运行之后，界面如下所示：

2、添加用户

add.jsp内容如下：

<%@ page language="java" contentType="text/html; charset=gb2312" %> <jsp:useBean id="user_add" scope="page" class="robin.web.userdao" /> <% String mesg = ""; String submit = request.getParameter("Submit"); if (submit!=null && !submit.equals("")){ if(user_add.getRequest(request)){ if (user_add.insert()){ response.sendRedirect("show.jsp"); } else { mesg = "Add data False!"; } } else { mesg = "Paras Error!"; } } %> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=gb2312"> <title>Robin JAVA Example</title> </head> <body> <h1>Add an User</h1> <% if (!mesg.equals("")){ out.println("<p><font color=Red>" + mesg + "</font></p>"); }%> <form method="post" action="add.jsp"> <table width=90% align=center> <tr><td colspan=2>请填写用户信息(此处未做UserId唯一性认证)：</td></tr> <tr><td>UserId: </td><td><input type=text name=txt_UserId size=40 maxlength=3 value=""></td></tr> <tr><td>UserName: </td><td><input type=text name=txt_UserName size=40 maxlength=20 value=""></td></tr> <tr><td>UserPsd: </td><td><input type=text name=txt_UserPsd size=40 maxlength=50 value=""></td></tr> <tr><td>UserDetail: </td><td><input type=text name=txt_UserDetail size=40 maxlength=100 value=""></td></tr> <tr><td></td><td><input type="submit" value="Add" name="Submit"></td></tr> </table> </form> </body> </html>

运行之后，界面如下所示：

添加成功之后，显示结果如下：

3、修改用户

Edit.jsp内容如下：

<%@ page language="java" contentType="text/html; charset=gb2312" %> <%@ page import="robin.model.userunit" %> <jsp:useBean id="user_edit" scope="page" class="robin.web.userdao" /> <% String mesg = ""; int userId =0; String submit = (String)request.getParameter("Submit"); if (submit!=null && !submit.equals("")){ if(user_edit.getRequest(request)){ if (user_edit.update()){ response.sendRedirect("show.jsp"); } else { mesg = "Edit data False!"; } } else { mesg = "Paras Error!"; } } if (request.getParameter("UserId")==null || request.getParameter("UserId").equals("")) { mesg = "Select Record Please!"; } else { try { userId = Integer.parseInt(request.getParameter("UserId")); if (!user_edit.getOneUser(userId)){ mesg = "No Record!"; } } catch (Exception e){ System.out.println("错误:"+e); mesg = "Get Paras Error!"; } } %> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=gb2312"> <title>Robin JAVA Example</title> </head> <body> <h1>Edit an User</h1> <% if (!mesg.equals("")){ out.println("<p><font color=Red>" + mesg + "</font></p>"); } else { userunit auser = (userunit) user_edit.getUserList().elementAt(0); %> <form method="post" action="edit.jsp"> <table width=90% align=center> <tr><td>UserId:</td><td><%= auser.getUserId() %></td></tr> <tr><td>UserName: </td><td><input type=text name=txt_UserName size=40 maxlength=100 value="<%= auser.getUserName() %>"></td></tr> <tr><td>UserPsd: </td><td><input type=text name=txt_UserPsd size=40 maxlength=100 value="<%= auser.getUserPsd() %>"></td></tr> <tr><td>UserDetail:</td><td><input type=text name=txt_UserDetail size=40 maxlength=100 value="<%= auser.getUserDetail() %>"></td></tr> <tr><td></td><td><input type=submit value="Edit" name="Submit"></td></tr></table> <input type=hidden name=txt_UserId value="<%= auser.getUserId() %>"> </form> <% } %> </body> </html>

运行之后，界面如下所示：

修改成功之后，显示结果如下：

4、删除用户

del.jsp内容如下：

<%@ page language="java" contentType="text/html; charset=gb2312" %> <jsp:useBean id="user_del" scope="page" class="robin.web.userdao" /> <% String mesg = ""; if (request.getParameter("UserId")!=null && !request.getParameter("UserId").equals("")){ try { int delid = Integer.parseInt(request.getParameter("UserId")); if (user_del.delete(delid)){ mesg = "Delete data success!"; } else { mesg = "Delete data false."; } } catch (Exception e){ mesg = "Select Record Please!"; } } else {mesg = "Select Record Please!";} %> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=gb2312"> <title>Robin JAVA Example</title> </head> <body> <h2>Delete an User Result</h2> <% if (!mesg.equals("")){ out.println("<p><font color=Red>" + mesg + "</font></p>"); }%> <br /> <table width=90% align=center> <tr> <td><a href="show.jsp" mce_href="show.jsp">查看数据</a></td> </tr> </table> </body> </html>

运行之后，界面如下所示：