开始本篇总结之前，首先聊一聊上一篇中存在的一点小问题，上上篇总结数据库创建表时，存在一个问题，name、year、form好像属于关键字，不能做为表的属性，所以大家注意一下，在创建表时保证表的属性不存在冲突，故而上一篇中关于sql语句的地方大家需要修改一下表的属性名。
下面开始本篇关于JSP与MYSQL的交互连接，为了方便总结，我将以创建一个学生信息管理系统为目标，本篇就以登录功能的实现为主体进行总结。
1、创建管理员表：
2、创建一个管理员类：
public class Manager {
private int id;
private String name ;
private String password;
private int key;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public int getKey() {
return key;
}
public void setKey(int key) {
this.key = key;
}
}
3、添加用户名、密码判断方法：
public class ManagerMaImp {
//登录验证
public boolean getByName(String name, String password){
System.out.println(name+" "+password);
boolean flag = false;
Connection conn = null;
Statement st = null;
ResultSet rs = null;
conn = DBO.getConnection();
String sql = "select * from manager where user_name=‘"+name+"‘ and pwd=‘"+password+"‘ and num="+1;
try {
st = conn.createStatement();
rs = st.executeQuery(sql);
if(rs.next()){
flag = true;
}
} catch (SQLException e) {
e.printStackTrace();
}
return flag;
}
}
4、设计登录JSP页面：
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>学生管理系统登录</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
</head>
<body>
<center>
<h1>学生管理系统登录</h1>
<hr/>
<form action="login" method="post" >
<table>
<tr>
<td>姓名：</td><td><input type="text" name="name" /></td>
</tr>
<tr>
<td>密码：</td><td><input type="password" name="pwd" /></td>
</tr>
<tr>
<td colspan="2" align="center"><input type="submit" value="登录"/></td>
</tr>
</table>
</form>
</center>
</body>
</html>
效果图：
5、用于身份判断的select：
public class login extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
request.setCharacterEncoding("utf-8");
response.setCharacterEncoding("utf-8");
String name = request.getParameter("name");
String password = request.getParameter("pwd");
ManagerMaImp mmi = new ManagerMaImp();
boolean flag = mmi.getByName(name, password);
if(flag){
StudentMaImp smi = new StudentMaImp();
List<Student> list = new ArrayList<Student>();
list = smi.getAll();
request.setAttribute("list", list);
request.getRequestDispatcher("All.jsp").forward(request, response);
}else{
response.sendRedirect("Login.jsp");
}
}
}
6、主界面（All.jsp）：
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@page import="com.mysql.jsp.student.Student"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>遍历数据库</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
</head>
<body>
<% List<Student> list = (List<Student>)request.getAttribute("list"); %>
<center>
<h1>遍历数据库中的数据</h1>
<hr/>
<form action="get" method="post">
<table width="80%">
<tr>
<td><a href="Add.jsp">添加</a></td><td> </td><td>精确查找:<input type="text" name="queding"/></td><td> </td><td>模糊查找:<input type="text" name="mohu"/></td>
</tr>
</table>
</form>
<table border="1" width="80%">
<TR>
<TD>ID</TD><td>姓名</td><td>性别</td><td>年龄</td><td>家乡</td><td>学校</td><td colspan="2">操作</td>
</TR>
<%
if(list.size()!=0){
for(int i=0; i<list.size(); i++){
Student student = list.get(i);
%>
<tr><TD><%=student.getId() %></TD><td><%=student.getName() %></td><td><%if(student.getSex()==1){ %>男<%}else{ %>女<%} %></td><td><%=student.getYear() %></td><td><%=student.getFrom() %></td><td><%=student.getSchool() %></td><td><a href="getId?id=<%=student.getId() %>">修改</a></td><td><a href="del?id=<%=student.getId() %>">删除</a></td></tr>
<%
}
}
%>
</table>
</center>
</body>
</html>
效果图：
本篇总结：本篇提到了select，JSP就是通过select与后台数据库进行交互的，我们上一篇总结的增删改查方法，将会在接下来的几篇一一为大家实现具体的使用。在主界面JSP代码中，你一定看到了很多:<%%>，我们可以在<%添加JAVA代码%>。
下一篇将系统为大家总结增、删、改的具体操作。
时间： 2024-08-25 16:51:36