走进浏览器对象之HttpServletRequest

可以在一次请求的处理过程中，在不同的Web组件之间传递对象信息。
有效期：一次请求的过程中。

测试HttpServletRequest :

1.新建一个web工程。
2.在src目录下新建一个报名为com.neusoft.httpServletRequest的包。
3.在该包下建立一个名为HttpServletRequestTest的servlet，HttpServletRequestTest的内容为：
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package com.neusoft.httpServletRequest;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class HttpServletRequestTest extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doPost(request, response);
}

public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=gb2312");
PrintWriter out = response.getWriter();
String userName = request.getParameter("userName");//从request请求对象中获得userName
String userPassWord = request.getParameter("userPassWord");//从request请求对象中获得userPassWord
out.println("userName:" + userName + "
" +"userPassWord:" + userPassWord);
out.flush();
out.close();
}