JSP+Servlet+JavaBean+JDBC實現使用者登入，及成績查詢
阿新 • • 發佈：2019-01-01
用Myeclipse新建web專案jsp+javabean，具體功能如下：
A. 建立與資料表相對應的javabean
B. 建立一個使用者登入頁面 ，輸入使用者名稱和密碼；
C. 建立一個連線資料庫、及資料庫操作的javabean（DateDao），用來連線資料庫、執行資料庫操作
D. 登入頁面提交時，servlet使用DateDao進行登入驗證；登入成功跳轉到顯示登入使用者成績的頁面，登入失敗跳轉到登入頁面；
1、建立Bean
package com.Server; import java.io.Serializable; public class Student implements Serializable { private int student_id; private String student_name; private int student_password; public Student(String name,int password) { this.student_name=name; this.student_password=password; } public void setStudent_id(int student_id) { this.student_id = student_id; } public int getStudent_id() { return student_id; } public void setStudent_name(String student_name) { this.student_name = student_name; } public String getStudent_name() { return student_name; } public void setStudent_password(int student_password) { this.student_password = student_password; } public int getStudent_password() { return student_password; } }
2、使用者登入介面JSP、顯示成績JSP
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%> <%@ page import="com.Server.Student"%> <!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=utf-8"> <title>使用者登入頁面</title> </head> <body> <form action="check_servlet" method="post"> <center> <table width="446" height="298" border="1"> <tr> <td colspan="2" align="center">登入頁面</td> </tr> <tr> <td width="92" align="center">使用者名稱：</td> <td width="232"><input type="text" name="studentname"></td> </tr> <tr> <td align="center">密碼:</td> <td><input type="password" name="studentpassword"></td> </tr> <tr> <td colspan="2" align="center"><input type="submit" value="登入"></td> </tr> </table> </center> </form> </body> </html>
<%@page import="java.awt.Window"%> <%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <title>顯示結果頁面</title> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> </head> <% String message = ""; String Sid = request.getParameter("Sid"); String getjava = request.getParameter("getjava"); String c = request.getParameter("c"); System.out.println(Sid+"score頁面"); String flag = request.getParameter("flag"); if(flag!=null&&flag.equals("success")) { message = "登入成功！"; }else if(flag!=null&&flag.equals("false")) { message = "登入失敗！"; Sid = "無"; getjava = "無"; c = "無"; } %> <body onload="jump()"> <center> <%=message %><br> ID:<%=Sid %><br> Java成績：<%=getjava %><br> c++成績：<%=c %><br> <a href="student_login.jsp">返回登陸</a> </center> <script type="text/javascript"> function jump() { if(flag==false) <% %> } </script> </body> </html>
3、DateDao.java 連線資料庫及操作
package com.Server;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class DateDao
{
public static Connection con = null;//定義連線
public static Statement st = null;//定義statement
public ResultSet result = null;//定義結果集
public static String driver;//定義驅動
public static String url;//定義URL
public static String user;//定義使用者名稱
public static String password;//定義密碼
//建立與資料庫連線的函式
public Connection getConn(){
try {
driver="com.mysql.jdbc.Driver";
url="jdbc:mysql://localhost:3306/test2";
user="root";
password="";
Class.forName(driver);
con = DriverManager.getConnection(url,user,password);//獲取資料庫連線
System.out.println("-------連線成功------");
}
catch (SQLException e)
{
e.printStackTrace();
}
catch (ClassNotFoundException e)
{
e.printStackTrace();
}
return this.con;
}
public DateDao()
{
this.con=this.getConn();
//建構函式，預設加裁配置檔案為jdbc.driver
}
// 執行資料庫查詢並返回查詢結果
public ResultSet query(String sql)
{
this.con=this.getConn();
try {
st = con.createStatement();//獲取Statement
result = st.executeQuery(sql);//執行查詢，返回結果集
} catch (Exception e)
{
e.printStackTrace();
}
return result;
}
//執行資料庫更新
public void update(String sql)
{
this.con=this.getConn();
try {
st = con.createStatement();//獲取Statement
st.executeUpdate(sql);//執行查詢，返回結果集
} catch (Exception e)
{
e.printStackTrace();
}
}
//關閉資料庫連線
public void close(){
try{
if (result != null)result.close();
if (st != null)st.close();
if (con != null)con.close();
}catch(Exception ex){
ex.printStackTrace();
}
}
}
4、Servlet呼叫DateDao操作資料庫
package Servlet;
import java.io.IOException;
import java.sql.ResultSet;
import java.sql.SQLException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.Server.DateDao;
import com.Server.Student;
public class check_servlet extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
{
doPost(request, response);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
{
DateDao mysql = new DateDao();
String context = request.getContextPath();
String username = new String(request.getParameter("studentname").getBytes("iso-8859-1"),"utf-8");
Integer userpassword = Integer.parseInt(request.getParameter("studentpassword"));
System.out.println(username);
System.out.println(userpassword);
String sql = "select*from student where Sname='"+username+"' and Password='"+userpassword+"'";
Student student= new Student(username,userpassword);
//驗證登入
ResultSet rs = mysql.query(sql);
try {
if (rs.next()){
//獲取該成員ID
Integer Sid = rs.getInt("Sid");
System.out.println(Sid);
mysql.close();//關閉連線
//通過ID查詢該成員成績
Integer getjava = 0;
Integer c = 0;
String scoresql = "select*from score where Sid ='"+Sid+"'";
ResultSet rs1 = mysql.query(scoresql);
if(rs1.next())
{
getjava = rs1.getInt("Java");
System.out.println(getjava);
c = rs1.getInt("c");
System.out.println(c);
mysql.close();//關閉連線
}
response.sendRedirect(context+"/student_score.jsp?flag=success&Sid="+Sid+"&getjava="+getjava+"&c="+c);
}else{
mysql.close();
response.sendRedirect(context+"/student_score.jsp?flag=false&Sid=null");
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}