demo servlet voi eclipse

From http://vovanhai.wordpress.com

Trong bài này, tôi sẽ hướng dẫn các bạn cấu hình Eclipse JavaEE và tạo 1 servlet đầu tiên.

Download Eclipse at: http://www.eclipse.org/downloads/ (Nhớ chọn version JavaEE nhé)

Chạy eclipse.

Cấu hình server:

Src: chứa source code WebContent chứa các trang JSP

Bạn có thể thêm các Init Params nếu muốn.

Bạn có thể sửa URL mapings nếu muốn.

Các methods có thể được implements, mặc định ở đây impls doGet, doPost.

Code sau khi tạo

package vovanhai.wordpress.com;

import java.io.IOException;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

/**

* Servlet implementation class LogonServlet

*/

public class LogonServlet extends HttpServlet {

private static final long serialVersionUID = 1L;

/**

* @see HttpServlet#HttpServlet()

*/

public LogonServlet() {

super();

// TODO Auto-generated constructor stub

}

/**

* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse

response)

*/

protected void doGet(HttpServletRequest request, HttpServletResponse

response) throws ServletException, IOException {

// TODO Auto-generated method stub

}

/**

* @see HttpServlet#doPost(HttpServletRequest request,

HttpServletResponse response)

*/

protected void doPost(HttpServletRequest request, HttpServletResponse

response) throws ServletException, IOException {

// TODO Auto-generated method stub

}

}

File config

<?xml version="1.0" encoding="UTF-8"?>

<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xmlns="http://java.sun.com/xml/ns/javaee"

xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"

xsi:schemaLocation="http://java.sun.com/xml/ns/javaee

http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID"

version="2.5">

<display-name>___NewFirstServlet</display-name>

<welcome-file-list>

<welcome-file>index.html</welcome-file>

<welcome-file>index.htm</welcome-file>

<welcome-file>index.jsp</welcome-file>

<welcome-file>default.html</welcome-file>

<welcome-file>default.htm</welcome-file>

<welcome-file>default.jsp</welcome-file>

</welcome-file-list>

<servlet>

<description></description>

<display-name>LogonServlet</display-name>

<servlet-name>LogonServlet</servlet-name>

<servlet-class>vovanhai.wordpress.com.LogonServlet</servlet-class>

</servlet>

<servlet-mapping>

<servlet-name>LogonServlet</servlet-name>

<url-pattern>/LogonServlet</url-pattern>

</servlet-mapping>

</web-app>

Code sửa lại cho servlet

package vovanhai.wordpress.com;

import java.io.IOException;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

/**

* Servlet implementation class LogonServlet

*/

public class LogonServlet extends HttpServlet {

private static final long serialVersionUID = 1L;

/**

* @see HttpServlet#HttpServlet()

*/

public LogonServlet() {

super();

}

/**

* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse

response)

*/

protected void doGet(HttpServletRequest request, HttpServletResponse

response) throws ServletException, IOException {

//ví dụ ở đây cả doPOst lần doGet dùng chung

doPost(request, response);

}

/**

* @see HttpServlet#doPost(HttpServletRequest request,

HttpServletResponse response)

*/

protected void doPost(HttpServletRequest request, HttpServletResponse

response) throws ServletException, IOException {

//lấy tham số từ người dùng

String us=request.getParameter("us");

String ps=request.getParameter("ps");

//Kiểm tra username, password

//Bạn có thể đăng nhập CSDL, kiểm tra. Ở đây để đơn giản tôi kiêm

tra us=ps không

if(us.equals(ps))

request.getRequestDispatcher("success.jsp").forward(request,

response);

else

request.getRequestDispatcher("failed.jsp").forward(request,

response);

}

}

Thiết kế trang web, Thêm trang JSP

<%@ page 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>

<form action="LogonServlet">

User name:<input name="us"/><br/>

Password:<input type="password" name="ps"/><br/>

<input type="submit" value="Logon"/>

<input type="reset" value="Clear"/>

</form>

</body>

</html>

Tạo 2 trang success.jsp và failed.jsp với nội dung tùy ý bạn

Thực thi ứng dụng

***Chú ý :

Import 1 dự án đã tồn tại vào eclipse :

Chúc thành công !