一.用户通过表单填写用户名和密码，然后提交给Servlet，Servlet可以获取参数，然后验证是否正确。
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 LoginServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public LoginServlet() {
super();
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doPost(request,response);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
request.setCharacterEncoding(\"GBK\");
response.setCharacterEncoding(\"GBK\");
PrintWriter out = response.getWriter();
String user = request.getParameter(\"user\");
String password = request.getParameter(\"password\");
if(user.equals(\"admin\")&&password.equals(\"123456\")){
out.println(\"登录成功\");
}else{
out.println(\"登录失败\");
}
}
}
<!DOCTYPE html>
<html>
<head>
< charset=\"UTF-8\">
< >登录测试</ >
< language=\" \">
function LoginSubmit(){
var user = document.Login.user.value;
var password = document.Login.password.value;
if(user==null||user==\"\"){
alert(\"请输入用户名\");
}else if(password==null||password==\"\"){
alert(\"请输入密码\");
}else document.Login.submit();
}
</ >
</head>
<body>
<form method=\"post\" name=\"Login\" action=\"LoginServlet\">
用户名：<input type=\"text\" name=\"user\"><br/>
密 码:<input type=\"text\" name=\"password\"><br/>
<input type=\"button\" value=\"提交\" name=\"B1\" =\"LoginSubmit()\">
<input type=\"reset\" value=\"重置\" name=\"B2\">
</form>
</body>
</html>
二.获取请求的报头信息
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 HttpHeadServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public HttpHeadServlet() {
super();
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doPost(request, response);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
request.setCharacterEncoding(\"GBK\");
response.setCharacterEncoding(\"GBK\");
PrintWriter out = response.getWriter();
out.println(request.getMethod());
//我们可以使用getHead()方法获取所有的报头信息，当然还有一些HttpServletRequest已经封装好了的函数。
out.println(request.getHeader(\"Accept\"));
}
}
这个HTML什么都没有提交，知识想获取他们里面的报头信息。
<!DOCTYPE html>
<html>
<head>
< charset=\"UTF-8\">
< >Insert here</ >
</head>
<body>
<form method=\"post\" action=\"HttpHeadServlet\">
<input type=\"submit\">
</form>
</body>
</html>
三。设置响应报头信息。
主要是通过setHead（）方法来设置响应的报头信息。
当然有一些也已经给封装好了。
比如：setContentType（）
addCookie（Cookie c）等。
package com.dh.ch01;
import java.io.IOException;
import java.io.PrintWriter;
import java.text.SimpleDateFormat;
import java.util.Date;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class DateServlet extends HttpServlet {
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException { // 获得一个向客户发送数据的输出流：
response.setContentType(\"text/html; charset=GBK\");// 设置响应的MIME类型。
PrintWriter out = response.getWriter();
out.println(\"<html>\");
out.println(\"<body>\");
response.setHeader(\"Refresh\", \"1\"); // 设置Refresh 的值。
out.println(\"现在时间是:\");
SimpleDateFormat sdf = new SimpleDateFormat(\"yyyy-MM-dd hh:mm:ss\");
out.println(\"<br/>\" + sdf.format(new Date()));
out.println(\"</body>\");
out.println(\"</html>\");
}
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request, response);
}
}
继续阅读与本文标签相同的文章
上一篇 :
阿里云携手NVIDIA拓展人工智能培训计划
下一篇 :
Android技术周报_W10
-
为什么支付宝有这么多“原生”技术牛人？
2026-05-18栏目： 教程
-
阿里巴巴小程序繁星计划 9月27日有话要说
2026-05-18栏目： 教程
-
为什么我会这么多技术，还这么难找工作
2026-05-18栏目： 教程
-
运营专家详解“花呗分期”
2026-05-18栏目： 教程
-
谈一谈 iOS 的锁
2026-05-18栏目： 教程