本文目錄一覽：
需要一個可以運行的JSP簡單代碼？
%@ page language=”java” import=”java.util.*” pageEncoding=”ISO-8859-1″%
%
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%”
titleMy JSP ‘index.jsp’ starting page/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”
!–
link rel=”stylesheet” type=”text/css” href=”styles.css”
—
/head
body
This is my JSP page. br
/body
/html
用文字語言描述下列JSP代碼意思
我給你寫上注釋吧
（1）
//註冊驅動
Class.forName(“sun.jdbc.odbc.JdbcOdbcDriver”).newInstance();
//根據url獲得數據庫連接
Connection con = DriverManager.getConnection(“jdbc:odbc:internet”,” “, ” “);
//用連接創建startment對象
Statement stmt = con.createStatement();
//獲取表單content內容,或者url傳來的content參數內容.
String content = request.getParameter(“content”);
//將content轉碼為GBK編碼
content = new String(content。getBytes(“ISO-8859-1”), “GBK”);
//創建日期格式化對象
java.text.DateFormat df = new java.text.SimpleDateFormat(“yyyy-MM-dd- HH:mm”);
//獲得當前電腦時間
java.util.Date date = new java.util.Date();
//將日期格式化為字符串,格式為:yyyy-MM-dd- HH:mm
String datestr = df.format(date);
//將datestr轉碼為GBK編碼
datestr = new String(datestr。getBytes(“ISO-8859-1”), “GBK”);
String msg = “您在留言成功。”;
//創建查詢sql語句
String sql2 = “select count(*) from liuyan_temp”;
// 查詢liuyan_temp表中所有數據的條數
ResultSet rs = stmt.executeQuery(sql2);
int i = 0;
//遍歷結果集
while (rs.next())
i = rs.getInt(1); //獲得liuyan_temp表記錄條數
i = i + 1;
——————————————————————–（2）
try {
//註冊驅動
Class.forName(“sun.jdbc.odbc.JdbcOdbcDriver”);
}
catch (ClassNotFoundException e) { //捕獲類未找到異常
out.print(e); //在jsp頁面打印異常信息
}
try {
//創建url信息
String url = “jdbc:odbc:internet”;
//獲得數據庫連接
conn = DriverManager.getConnection(url, ” “, ” “);
//根據sql語句創建PrepareStatement
ps = conn.prepareStatement(“select * from shipin”);
//執行查詢,返回結果集
result = ps.executeQuery();
//遍歷結果集
while (result.next()) {
—————————————————————–
（3）
try{
//註冊驅動
Class.forName(“sun.jdbc.odbc.JdbcOdbcDriver”);
}catch(ClassNotFoundException cnfe){//捕獲類未找到異常
out.println(cnfe); //打印異常
}
try{
String url = “jdbc:odbc:internet”;
//創建數據庫連接
conn = DriverManager.getConnection(url,””,””);
//根據sql語句創建PrepareStatement
psSelect = conn.prepareStatement(“select * from userInformation where userID=?”);
//為sql語句中第一個問好設置值
psSelect.setString(1,userID);
//執行查詢,返回結果集
result = psSelect.executeQuery();
//判斷,如果結果集中有查詢結果
if(result.next()){%
tr
!– 輸出結果集當前行第一個字段的值 —
td%=result.getString(1) %/td
!– 輸出結果集當前行第二個字段的值 —
td%=result.getString(2) %/td
/tr
//判斷,結果集中沒有查詢結果
%}else{
//打印JavaScript信息
out.println(“scriptalert(‘查詢錯誤，請重新輸入！’)”);
//瀏覽器的頁面url指向manageUser.jsp頁面(javascript方法)
out.println(“window.navigate(‘manageUser.jsp’)/script”);
jsp登陸界面源代碼
1、login.jsp文件
%@ page language=”java” contentType=”text/html; charset=GB18030″
pageEncoding=”GB18030″%
%@ page import=”java.util.*” %
!DOCTYPE HTML PUBLIC “-//W3C//DTD HTML 4.01 Transitional//EN”
html
head
title登錄頁面/title
/head
body
form name=”loginForm” method=”post” action=”judgeUser.jsp”
table
tr
td用戶名:input type=”text” name=”userName” id=”userName”/td
/tr
tr
td密碼:input type=”password” name=”password” id=”password”/td
/tr
tr
tdinput type=”submit” value=”登錄” style=”background-color:pink” input
type=”reset” value=”重置” style=”background-color:red”/td
/tr
/table
/form
/body
/html
2、judge.jsp文件
%@ page language=”java” contentType=”text/html; charset=GB18030″
pageEncoding=”GB18030″%
%@ page import=”java.util.*” %
!DOCTYPE HTML PUBLIC “-//W3C//DTD HTML 4.01 Transitional//EN”
html
head
title身份驗證/title
/head
body
%
request.setCharacterEncoding(“GB18030”);
String name = request.getParameter(“userName”);
String password = request.getParameter(“password”);
if(name.equals(“abc”) password.equals(“123”)) {
3、afterLogin.jsp文件
%
jsp:forward page=”afterLogin.jsp”
jsp:param name=”userName” value=”%=name%”/
/jsp:forward
%
}
else {
%
jsp:forward page=”login.jsp”/
%
}
%
/body
/html
%@ page language=”java” contentType=”text/html; charset=GB18030″
pageEncoding=”GB18030″%
!DOCTYPE HTML PUBLIC “-//W3C//DTD HTML 4.01 Transitional//EN”
html
head
title登錄成功/title
/head
body
%
request.setCharacterEncoding(“GB18030”);
String name = request.getParameter(“userName”);
out.println(“歡迎你:” + name);
%
/body
/html
擴展資料：
java web登錄界面源代碼：
1、Data_uil.java文件
import java.sql.*;
public class Data_uil
{
public Connection getConnection()
{
try{
Class.forName(“com.microsoft.sqlserver.jdbc.SQLServerDriver”);
}catch(ClassNotFoundException e)
{
e.printStackTrace();
}
String user=”***”;
String password=”***”;
String url=”jdbc:sqlserver://127.0.0.1:1433;DatabaseName=***”;
Connection con=null;
try{
con=DriverManager.getConnection(url,user,password);
}catch(SQLException e)
{
e.printStackTrace();
}
return con;
}
public String selectPassword(String username)
{
Connection connection=getConnection();
String sql=”select *from login where username=?”;
PreparedStatement preparedStatement=null;
ResultSet result=null;
String password=null;
try{
preparedStatement=connection.prepareStatement(sql);
preparedStatement.setString(1,username);
result=preparedStatement.executeQuery();//可執行的 查詢
if(result.next())
password=result.getString(“password”);
}catch(SQLException e){
e.printStackTrace();
}finally
{
close(preparedStatement);
close(result);
close(connection);
}
System.out.println(“找到的數據庫密碼為：”+password);
return password;
}
public void close (Connection con)
{
try{
if(con!=null)
{
con.close();
}
}catch(SQLException e)
{
e.printStackTrace();
}
}
public void close (PreparedStatement preparedStatement)
{
try{
if(preparedStatement!=null)
{
preparedStatement.close();
}
}catch(SQLException e)
{
e.printStackTrace();
}
}
public void close(ResultSet resultSet)
{
try{
if(resultSet!=null)
{
resultSet.close();
}
}catch(SQLException e)
{
e.printStackTrace();
}
}
}
2、login_check.jsp:文件
%@ page language=”java” contentType=”text/html; charset=utf-8″
pageEncoding=”utf-8″%
!DOCTYPE html PUBLIC “-//W3C//DTD HTML 4.01 Transitional//EN” “”
html
head
meta http-equiv=”Content-Type” content=”text/html; charset=utf-8″
title驗證用戶密碼/title
/head
body
jsp:useBean id=”util” class=”util.Data_uil” scope=”page” /
%
String username=(String)request.getParameter(“username”);
String password=(String)request.getParameter(“password”);
if(username==null||””.equals(username))
{
out.print(“script language=’javaScript’ alert(‘用戶名不能為空’);/script”);
response.setHeader(“refresh”, “0;url=user_login.jsp”);
}
else
{
System.out.println(“輸入的用戶名:”+username);
String passwordInDataBase=util.selectPassword(username);
System.out.println(“密碼：”+passwordInDataBase);
if(passwordInDataBase==null||””.equals(passwordInDataBase))
{
out.print(“script language=’javaScript’ alert(‘用戶名不存在’);/script”);
response.setHeader(“refresh”, “0;url=user_login.jsp”);
}
else if(passwordInDataBase.equals(password))
{
out.print(“script language=’javaScript’ alert(‘登錄成功’);/script”);
response.setHeader(“refresh”, “0;url=loginSucces.jsp”);
}
else
{
out.print(“script language=’javaScript’ alert(‘密碼錯誤’);/script”);
response.setHeader(“refresh”, “0;url=user_login.jsp”);
}
}
%
/body
/html
3、loginSucces.jsp文件
%@ page language=”java” contentType=”text/html; charset=utf-8″
pageEncoding=”utf-8″%
!DOCTYPE html PUBLIC “-//W3C//DTD HTML 4.01 Transitional//EN” “”
html
head
meta http-equiv=”Content-Type” content=”text/html; charset=ISO-8859-1″
titleInsert title here/title
/head
body
hr size=”10″ width=”26%” align=”left” color=”green”
font size=”6″ color=”red” 登錄成功 /font
hr size=”10″ width=”26%” align=”left” color=”green”
/body
/html
4、user_login.jsp文件
%@ page language=”java” contentType=”text/html; charset=utf-8″
pageEncoding=”utf-8″%
!DOCTYPE html PUBLIC “-//W3C//DTD HTML 4.01 Transitional//EN” “”
html
head
meta http-equiv=”Content-Type” content=”text/html; charset=ISO-8859-1″
title登錄界面/title
/head
body background=”C:\Users\win8\workspace\Login\image\9dcbdc339e72a5663b5c289fb5573c13_10.jpg”
center
brbrbrbrbrbr
h1 style=”color:yellow”Login/h1
br
form name=”loginForm” action=”login_check.jsp” method=”post”
table Border=”0″
tr
td賬號/td
tdinput type=”text” name=”username”/td
/tr
tr
td密碼/td
tdinput type=”password” name=”password”
/td
/tr
/table
br
input type=”submit” value=”登錄” style=”color:#BC8F8F”
/form
/center
/body
/html
求大神寫一下jsp的簡單的註冊界面代碼。
1.需要一個jsp頁面：
//login.jsp核心代碼：
form action=”${pageContext.request.contextPath}/servlet/UserServlet” method=”post”
input type=”text” name=”loginname” /input type=”password” name=”password”/
input type=”submit” value=”登錄”/
/form
2.需要一個servlet來驗證登錄信息
//UserServlet 核心代碼
class UserServlet extends HttpServlet{
protected void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {
process(request, response);
}
protected void doPost(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {
process(request, response);
}
private void process(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {
PrintWriter pw = response.getWriter();
request.setCharacterEncoding(“UTF-8”);
response.setContentType(“text/html”);
String loginname = request.getParameter(“loginname”);
String password = request.getParameter(“password”);
//創建一個service來處理業務邏輯（包括查詢數據庫操作）
UserService service = new UserService();
boolean bool = service.validateUser(loginname,password);
if(!bool){
pw.println(“用戶名或密碼錯誤”);
}else{
pw.println(“登錄成功”);
}
}
3.需要一個service處理業務邏輯（包括查詢數據庫操作）
//UserService 核心代碼
public class UserService{
/**
*查詢數據庫驗證用戶是否存在，返回boolean
*/
public boolean validateUser(String loginname,String password){
boolean bool = false;
Connection conn = null;
PreparedStatement ps = null;
//這裡以mysql為例
try {
Class.forName(“com.mysql.jdbc.Driver”).newInstance();
conn = DriverManager.getConnection(“jdbc:mysql://localhost:3306/test”, “root”, “”);
String sql = “select login_name,pass_word from t_user where login_name=? and pass_word=?”;
ps = conn.prepareStatement(sql);
ps.setString(0, loginname);
ps.setString(1, password);
ResultSet rs = ps.executeQuery();
if(rs.next()){
bool = true;
}
} catch (Exception e) {
e.printStackTrace();
} finally{
try {
if(conn != null){
conn.close();
conn = null;
}
if(ps != null){
ps.close();
ps = null;
}
} catch (SQLException e) {
e.printStackTrace();
}
}
return bool;
}
}
原創文章，作者：YDCF，如若轉載，請註明出處：https://www.506064.com/zh-hant/n/145165.html
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