二、创建Servlet

三、编写代码

ServletRequestTest.java:

package com.servlet.test;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class ServletRequestTest extends HttpServlet {

	private static final long serialVersionUID = 1L;

	public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

		doPost(request, response);
	}

	public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		//解决请求参数乱码
		// 1.post请求方式的数据是以二进制流的形式发送到服务器。
	    // 2.那么就说明它缺少一个字符集。所以我们要设置请求体的字符集即可。
	    // setCharacterEncoding必须要获取请求参数之前调用才有效
	    request.setCharacterEncoding("UTF-8");
	    //解决返回显示内容乱码
	    //告诉浏览器输出的内容是html,并且以utf-8的编码来查看这个内容。
	    response.setContentType("text/html; charset=utf-8");
	    String username = request.getParameter("username");
	    System.out.println(username);
	}

}

访问Servlet的Jsp页面：

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
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%>">
    
    <title>Test Servlet page</title>
  </head>
  
  <body>
    <!-- action 后的路径为新建servlet是配置的路径 这里使用的是默认的路径 -->
    <form action="servlet/ServletRequestTest" method="post">
    	<input type="text" name="username"/>
    	<input type="submit" value="提交"/>
    </form>
  </body>
</html>