數據庫鏈接的WEB登陸界面的實現

時間 2019-11-19

標籤數據庫鏈接 web 登陸界面實現欄目 SQL 简体版

原文原文鏈接

要實現此功能，須要電腦安裝JAVA EE、SQL Server 2008和Tomcat等軟件，並進行配置環境成功。html

對這門課的但願和本身的目標：java

但願：能夠徹底掌握老師所講的內容。sql

目標：可以完整的作出一個網站。數據庫

計劃每週花多少時間在這門課上：jsp

每週的天天均儘可能花1個小時的時間在敲代碼上。sqlserver

接下來~post

1、首先須要建立數據庫，並在數據庫中建立數據表，列表以下：網站

建成以後的數據表如圖所示：ui

2、而後，打開JAVA EE，開始建立WEB項目。url

3、建立jsp文件，以下：

<%@ page import="java.sql.*" language="java" contentType="text/html; charset=utf-8"
    pageEncoding="utf-8"%>
<!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>登陸界面</title>
</head>
<body>
    <center>
        <h1 style="color:red">登陸</h1>
            <form id="indexform" name="indexForm" action="logincheck.jsp" method="post">
                <table border="0">
                    <tr>
                        <td>帳號：</td>
                        <td><input type="text" name="username"></td>
                    </tr>
                    <tr>
                        <td>密碼：</td>
                        <td><input type="password" name="password">
                        </td>
                    </tr>
                </table>
            <br>
                <input type="submit" value="登陸" style="color:#BC8F8F">
            </form>
    </center>
</body>
</html>

logincheck.jsp

<%@ page import="java.sql.*" language="java" contentType="text/html; charset=utf-8"
    pageEncoding="utf-8"%>
<!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>Insert title here</title>
</head>
<body>
<jsp:useBean id="db" class="Bean.DBBean" scope="page"/>
<%
    request.setCharacterEncoding("UTF-8");
    String username=(String)request.getParameter("username");
    String password=(String)request.getParameter("password");//取出login.jsp的值
    
    
    //下面是數據庫操做 *表明全部值
    String sql="select * from lhT where username="+"'"+username+"'";//定義一個查詢語句
    ResultSet rs=db.executeQuery(sql);//運行上面的語句
    if(rs.next())
    {
        /* if(password.equals(rs.getString(2)))
        {
            
        } */
        if(password.equals(rs.getObject("password"))){
            response.sendRedirect("loginsuccess.jsp");
        }
        else{
            out.print("<script language='javaScript'> alert('密碼錯誤');</script>");
            response.setHeader("refresh", "0;url=login.jsp");
        }
    }
    else 
    {
        out.print("<script language='javaScript'> alert('請輸入用戶名——else');</script>");
        response.setHeader("refresh", "0;url=login.jsp");
    }
    
%>
</body>
</html>

loginsuccess.jsp

<%@ page import="java.sql.*" language="java" contentType="text/html; charset=utf-8"
    pageEncoding="utf-8"%>
<!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=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<h1>登陸成功 </h1>
</body>
</html>

4、而後是其餘文件的建立：

建立DBBean.java,鏈接數據庫

package Bean;
import java.sql.*;
public class DBBean {
    private String driverStr = "com.microsoft.sqlserver.jdbc.SQLServerDriver";
    private String connStr = "jdbc:sqlserver://localhost:1433; DatabaseName=lhsjk";
    private String dbusername = "ABC";
    private String dbpassword = "123";
    private Connection conn = null;
    private Statement stmt = null;

    public DBBean()
    {
        try
        {
            Class.forName(driverStr);
            conn = DriverManager.getConnection(connStr, dbusername, dbpassword);
            stmt = conn.createStatement();
        } 
        catch (Exception ex) {
            System.out.println(ex.getMessage());
            System.out.println("數據鏈接失敗！");
        } 
        
    }

    public int executeUpdate(String s) {
        int result = 0;
        System.out.println("--更新語句:"+s+"\n");
        try {
            result = stmt.executeUpdate(s);
        } catch (Exception ex) {
            System.out.println("執行更新錯誤！");
        }
        return result;
    }

    public ResultSet executeQuery(String s) {
        ResultSet rs = null;
        System.out.print("--查詢語句:"+s+"\n");
        try {
            rs = stmt.executeQuery(s);
        } catch (Exception ex) {
            System.out.println("ִ執行查詢錯誤！");
        }
        return rs;
    }
    public void execQuery(String s){
        try {
            stmt.executeUpdate(s);
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            System.out.println("執行插入錯誤！");
        }
    }

    public void close() {
        try {
            stmt.close();
            conn.close();
        } catch (Exception e) {
        }
    }
}