Servlet處理客戶端HTTP請求
本篇部落格將在上一篇部落格《Servlet第一個示例》的基礎上繼續介紹，Servlet如何處理客戶端的請求，獲得客戶端的請求訊息。
首先我們新建一個靜態頁面index.html，用於向Servlet提交請求。
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Servlet</title>
</head>
<body>
<form action="Test" method="POST">
<table 然後，我們需要修改Test中的方法，因為頁面採用POST方式提交，所以在Test Servlet中，我們僅對Post的請求做處理。
package com.gujin.servlet;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Enumeration;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class Test extends HttpServlet
{
private static final long serialVersionUID = 1L;
protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException
{
request.setCharacterEncoding("UTF-8");
// 獲得請求頭資訊
System.out.println("======HEAD INFO======");
Enumeration enumeration = request.getHeaderNames();
while (enumeration.hasMoreElements())
{
String name = (String) enumeration.nextElement();
Enumeration headers = request.getHeaders(name);
while (headers.hasMoreElements())
{
System.out.println(name + ":" + headers.nextElement());
}
}
// 獲得請求引數
System.out.println("======REQUEST PARAM======");
// 獲得指定引數
// request.getParameter("userId");
// 獲得所有請求引數名稱
// request.getParameterNames();
// 獲得請求引數集合
// request.getParameterMap();
Enumeration names = request.getParameterNames();
while (names.hasMoreElements())
{
String name = (String) names.nextElement();
System.out.println(name + ":" + request.getParameter(name));
}
PrintWriter writer = response.getWriter();
writer.print("Hello Servlet");
writer.flush();
writer.close();
}
}
輸入一些內容後提交，我們會看到服務端的後臺會輸出如下內容（內容可能會不一樣）：
======HEAD INFO======
accept:image/gif, image/jpeg, image/pjpeg, image/pjpeg, application/x-shockwave-flash, application/xaml+xml, a
pplication/vnd.ms-xpsdocument, application/x-ms-xbap, application/x-ms-application, /
referer:http://localhost/Servlet/
accept-language:zh-CN
user-agent:Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0; .NET CLR 3.0.04506.30; .NET CLR 2.0
.50727; hwvcloud4; hwcloud4)
content-type:application/x-www-form-urlencoded
accept-encoding:gzip, deflate
host:localhost
content-length:77
connection:Keep-Alive
cache-control:no-cache
======REQUEST PARAM======
userId:jianggujin
userSex:1
interest2:on
userName:蔣固金
這樣我麼就可以根據客戶端請求的內容做相應的業務處理。