HTTP简介
WEB浏览器与WEB拂去其之间的一问一答的交互过程, 必须遵循一定的规则,这个规则就是HTTP协议
HTTP是hypertext transfer protocol(超文本传输协议)的简写, 它是TCP/IP协议集中的一个应用层协议, 用于定义WEB浏览器与WEB服务器之间交换数据的过程以及数据本身的格式
HTTP协议的版本 HTTP/1.0 HTTP/1.1 HTTP-NG
HTTP的会话方式
四个步骤
1> 建立连接
2> 发出请求信息
3> 回送响应信息
4> 关闭连接
浏览器与WEB服务器之间的链接过程式短暂的, 每次链接只处理一个请求和响应. 对每一个页面的访问, 浏览器与WEB服务器都要建立一次单独的连接.
浏览器到WEB服务器之间的所有通讯都是完全独立分开的请求和响应对儿
创建项目testHttpForm ---> package(com.xiaoan.test) --> class(TestForm.java)
package com.xiaoan.test; import java.io.IOException;
import java.util.Arrays;
import java.util.Enumeration;
import java.util.Map;
import java.util.Map.Entry; import javax.servlet.Servlet;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.swing.plaf.synth.SynthSeparatorUI; public class TestForm implements Servlet{ @Override
public void destroy() {
// TODO Auto-generated method stub } @Override
public ServletConfig getServletConfig() {
// TODO Auto-generated method stub
return null;
} @Override
public String getServletInfo() {
// TODO Auto-generated method stub
return null;
} @Override
public void init(ServletConfig arg0) throws ServletException {
// TODO Auto-generated method stub } @Override
public void service(ServletRequest request, ServletResponse response) throws ServletException, IOException {
System.out.println("this is Servlet service function");
//1 获取请求参数 k--v
String username = request.getParameter("username");
String password = request.getParameter("password");
System.out.println("username: " + username);
System.out.println("password: " + password);
//获取请求参数 k -- v1,v2,v3 - 表单中checkbox类型数据
String[] reads = request.getParameterValues("read");
for(String read: reads){
System.out.println("-->read: " + read);
} //获取所有的参数名
Enumeration<String> keys = request.getParameterNames(); //获取所有的请求参数 <k,v>
Map<String, String[]> params = request.getParameterMap();
for(Map.Entry<String, String[]> param: params.entrySet()){
System.out.println("****" + param.getKey() + ": " + Arrays.asList(param.getValue()));
} /*
* HttpServletRequest: 是 SerlvetRequest 的子接口. 针对于 HTTP 请求所定义. 里边包含了大量获取 HTTP 请求相关的方法.
*/ //获取请求的URI
HttpServletRequest httpServletRequest = (HttpServletRequest) request;
String uri = httpServletRequest.getRequestURI();
System.out.println("request uri: " + uri); //获得请求方式
String method = httpServletRequest.getMethod();
System.out.println("request method: " + method); //如果是get请求, 则获得问号传参后面的部分, 如果是post请求该项返回null
String getstr = httpServletRequest.getQueryString();
System.out.println("getstr: " + getstr); //获取请求的 Serlvet 的映射路径
String servletPath = httpServletRequest.getServletPath();
System.out.println(servletPath);
} }
--> 配置web.xml
<?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" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
<display-name>testHttpForm</display-name> <servlet>
<servlet-name>formServlet</servlet-name>
<servlet-class>com.xiaoan.test.TestForm</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>formServlet</servlet-name>
<url-pattern>/formServlet</url-pattern>
</servle
写表单(WebContent目录下) 新建testform.html
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<form action="/testHttpForm/formServlet" method="get">
username: <input type="text" name="username"><br>
password: <input type="password" name="password"><br>
多选测试:<input type="checkbox" name="read" value=1>1
<input type="checkbox" name="read" value=2>2
<input type="checkbox" name="read" value=3>3
<input type="checkbox" name="read" value=4>4
<input type="checkbox" name="read" value=5>5
<input type="submit" name="submit" value="提交">
</form>
</body>
</html>
提交方式 get和post切换一下, 看看有什么不同