1.開啟Eclipse,單擊Flie→New→Project..出現New Project對話框如下圖。

選擇MyEclipse→J2EE Projects→Web Project單擊Next如下圖。

在Project Name文本框中寫入logindemo其它保持默認選項單擊Finish按鈕。此時在Package Explorer(包瀏覽器)中出現我們新建的項目,把項目展開在src文件夾上單擊右鍵選擇New→Package出現New Java Package對話框如下圖

在Name文本框中寫入register單擊Finish按鈕。在src文件夾中新建了一個register包,用同樣的方法在src文件夾中建一個login包。右鍵單擊register包選擇New→Class出現New Java Class對話框如下圖

在Name文本框中填寫Register單擊Finish按鈕。在register包下生成Register.java文件,更改其內容如下:
package
register;
import
java.io.
*
;
import
java.util.
*
;
import
javax.servlet.
*
;
import
javax.servlet.http.
*
;
import
java.sql.
*
;
//
import com.mysql.jdbc.*;
public
class
Register
extends
HttpServlet 
...
{
private String name;
private String pass;
private String confirm;
public synchronized void doPost(HttpServletRequest request,HttpServletResponse response)
throws ServletException,IOException 
...{
this.name=request.getParameter("account");
this.pass=request.getParameter("password");
this.confirm=request.getParameter("confirm");
PrintWriter out=response.getWriter();
//驅動程序名
String driverName="com.mysql.jdbc.Driver";
//數據庫用戶名
String userName="root";
//密碼
String userPasswd="123";
//數據庫名
String dbName="database";
//表名
String tableName="users";
//聯結字符串
String url="jdbc:mysql://localhost/"+dbName+"?user="+userName+"&password="+userPasswd;
try 
...{
Class.forName("org.gjt.mm.mysql.Driver");
Connection connection=DriverManager.getConnection(url);
Statement statement = connection.createStatement();
String sql="SELECT * FROM "+tableName;
ResultSet rs=statement.executeQuery(sql);
while(true) 
...{
if(rs.next()) 
...{
if(this.name.equals(rs.getString(1))) 
...{
out.print("<h1>"+"User Name is in Database!");
break;
}
}
else 
...{
sql="INSERT INTO "+tableName+" VALUES('"+this.name+"','"+this.pass+"')";
statement.execute(sql);
out.print("<h1>"+"Register Successful!");
break;
}
}
return;
}
catch(SQLException e) 
...{
}
catch(ClassNotFoundException e) 
...{
}
}
public synchronized void doGet(HttpServletRequest request,HttpServletResponse response)
throws ServletException,IOException 
...{
doPost(request,response);
}
}
用同樣的方法在login包下建一個Login.java文件,其內容如下:
package
login;
import
java.io.
*
;
import
java.util.
*
;
import
javax.servlet.
*
;
import
javax.servlet.http.
*
;
import
java.sql.
*
;
//
import com.mysql.jdbc.*;
public
class
Login
extends
HttpServlet 
...
{
private String name;
private String pass;
public synchronized void doPost(HttpServletRequest request,HttpServletResponse response)
throws ServletException,IOException 
...{
this.name=request.getParameter("account");
this.pass=request.getParameter("password");
PrintWriter out=response.getWriter();
//驅動程序名
String driverName="com.mysql.jdbc.Driver";
//數據庫用戶名
String userName="root";
//密碼
String userPasswd="123";
//數據庫名
String dbName="database";
//表名
String tableName="users";
//聯結字符串
String url="jdbc:mysql://localhost/"+dbName+"?user="+userName+"&password="+userPasswd;
try 
...{
Class.forName("org.gjt.mm.mysql.Driver");
Connection connection=DriverManager.getConnection(url);
Statement statement = connection.createStatement();
String sql="SELECT * FROM "+tableName;
ResultSet rs = statement.executeQuery(sql);
while(true) 
...{
if(rs.next()) 
...{
if((this.name.equals(rs.getString(1)))&&(this.pass.equals(rs.getString(2)))) 
...{
out.print("<h1>"+"Login Success!");
break;
}
}
else 
...{
out.print("<h1>"+"Account or Password Is Invalid!");
break;
}
}
return;
}
catch(SQLException e) 
...{
}
catch(ClassNotFoundException e) 
...{
}
}
public synchronized void doGet(HttpServletRequest request,HttpServletResponse response)
throws ServletException,IOException 
...{
doPost(request,response);
}
}
在WebRoot文件夾上單擊右鍵點擊New→JSP出現Create a new JSP page對話框如下圖

在File Name文本框中填寫index.jsp單擊Finish按鈕。更改其內容如下:
<%
...
@ page language="java" import="java.util.*" pageEncoding="ISO-8859-1"
%>
<
html
>
<
body
bgcolor
=white
><
Font
size
=1
>

<
script
language
="javascript"
>
...
function login_click() 
...{
form1.action="Login";
form1.submit();
}
function register_click() 
...{
form1.action="register.jsp";
form1.submit();
}
</
script
>
<
form
name
="form1"
>
<
table
>
<
tr
>
td align="center">
Account:
</
td
>
<
td
>
<
input
size
="18"
type
="text"
name
="account"
>
</
td
>
</
tr
>
<
tr
>
<
td
align
="center"
>
Password:
</
td
>
<
td
>
<
input
size
="20"
type
="password"
name
="password"
>
</
td
>
</
tr
>
</
table
>
<
table
>
<
tr
>
<
td
width
="60"
>
</
td
>
<
td
width
="80"
>
<
input
type
="submit"
name
="register"
value
="register"
onClick
="return register_click()"
>
</
td
>
<
td
width
="80"
>
<
input
type
="submit"
name
="login"
value
=" login "
onClick
="return login_click()"
>
</
td
>
</
tr
>
</
table
>
</
form
>
</
body
>
</
html
>
用同樣的方法在WebRoot目錄下創建一個register.jsp文件,其內容如下:
<%
...
@ page language="java" import="java.util.*" pageEncoding="ISO-8859-1"
%>
<
html
>
<
body
bgcolor
=white
><
Font
size
=1
>
<
form
action
="Register"
>
<
table
>
<
tr
>
<
td
align
="center"
>
Register Account:
</
td
>
<
td
>
<
input
size
="18"
type
="text"
name
="account"
>
</
td
>
</
tr
>
<
tr
>
<
td
align
="center"
>
Password:
</
td
>
<
td
>
<
input
type
="password"
name
="password"
>
</
td
>
</
tr
>
<
tr
>
<
td
>
Confirm Password:
</
td
>
<
td
align
="center"
>
<
input
type
="password"
name
="confirm"
>
</
td
>
</
tr
>
</
table
>
<
table
>
<
tr
>
<
td
width
="116"
>
</
td
>
<
td
width
="120"
>
<
input
type
="submit"
name
="register"
value
="register"
>
</
td
>
</
tr
>
</
table
>
</
form
>
</
body
>
</
html
>
修改WebRoot/WEB-INF目錄下的web.xml文件,修改后的web.xml文件內容如下:
<?
xml version="1.0" encoding="ISO-8859-1"
?>
<!
DOCTYPE web-app
PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/dtd/web-app_2_3.dtd"
>
<
web-app
>
<
display-name
>
My Web Application
</
display-name
>
<
description
>
A application for test.
</
description
>
<
servlet
>
<
servlet-name
>
Login
</
servlet-name
>
<
display-name
>
Login
</
display-name
>
<
description
>
A login Servlet
</
description
>
<
servlet-class
>
login.Login
</
servlet-class
>
</
servlet
>
<
servlet-mapping
>
<
servlet-name
>
Login
</
servlet-name
>
<
url-pattern
>
/Login
</
url-pattern
>
</
servlet-mapping
>
<
servlet
>
<
servlet-name
>
Register
</
servlet-name
>
<
display-name
>
Register
</
display-name
>
<
description
>
A Register Servlet
</
description
>
<
servlet-class
>
register.Register
</
servlet-class
>
</
servlet
>
<
servlet-mapping
>
<
servlet-name
>
Register
</
servlet-name
>
<
url-pattern
>
/Register
</
url-pattern
>
</
servlet-mapping
>
</
web-app
>
開啟MySql服務器,在控制面板→管理工具→服務中找到MySql服務啟動該服務。打開MySQL Administrator輸入數據庫用戶名和密碼進入數據庫如下圖

在MySQL Administrator中選擇Tools→MySql Query Browser進入查詢瀏覽器在查詢瀏覽器中建立一個名為database的數據庫,在database數據庫中建立一個名為users的表,並為users表建立2個字段name和password到此數據庫建立完畢。
在logindemo項目上單擊右鍵選擇MyEclipse→Add and Remove Project Deployments...彈出Project Deployments對話框如下圖

在Project下拉選項框中選logindemo然后單擊add按鈕出現New Deployment對話框如下圖

在server下拉選項框中選擇Tomcat5單擊Finish按鈕,再單擊OK按鈕我們的項目就部署好了。接下來在Eclipse中啟動Tomcat服務器,然后在瀏覽器的地址欄里輸入http://localhost:8080/logindemo/index.jsp就看到下面的結果了

先要注冊一個用戶名,如果數據庫中有這個用戶名就會顯示“User Name is in Database”如果沒有就會注冊成功然后返回登錄頁面用這個用戶名登錄輸入正確的用戶名和密碼就會顯示“Login Success!”否則顯示“Account or Password Is Invalid!”需要注意的是我這里登錄數據庫的用戶名為root密碼為123需要根據實際情況修改相應java文件中的用戶名和密碼。