javaweb之request获取请求头和请求数据

来源：互联网发布：耐克抢鞋软件编辑：程序博客网时间：2024/04/27 19:06

package test.request;import java.io.IOException;import java.io.InputStream;import java.lang.reflect.InvocationTargetException;import java.util.Enumeration;import java.util.Map;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import com.sun.org.apache.commons.beanutils.BeanUtils;//HttpServletRequest获取请求头和请求数据//请求数据一半来说要先检查再使用，检查非空和不是空格public class RequestDemo2 extends HttpServlet {public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {System.out.println("---------获取请求数据方式1-------------");// 获取指定的请求数据String value = request.getParameter("username");if (value != null && !value.trim().equals("")) {System.out.println(value);}System.out.println("---------获取请求数据方式2-------------");// 获取所有的请求数据Enumeration e = request.getParameterNames();while (e.hasMoreElements()) {String paramName = (String) e.nextElement();String value2 = request.getParameter(paramName);System.out.println(paramName + "=" + value2);}System.out.println("---------获取请求数据方式3-------------");// 获取所有的请求数据，同名的只能获取一次，就是第一次String[] values = request.getParameterValues("username");for (int i = 0; values != null && i < values.length; i++) {System.out.println(values[i]);}System.out.println("---------获取请求数据方式4-------------");// 这个特别实用，框架的模型驱动，这个Map的value肯定是String数组类型，因为有同名的请求数据// 实际开发中是不会 request.getParameter("username");用这种方式的，都是要创建一个model的Map<String, String[]> map = request.getParameterMap();User user = new User();try {// 用map中的数据填充beanBeanUtils.populate(user, map);} catch (IllegalAccessException e1) {e1.printStackTrace();} catch (InvocationTargetException e1) {e1.printStackTrace();}System.out.println(user.getPassword());System.out.println("---------获取请求数据方式5-------------");// request.getInputStream();是上传文件的时候获取数据的方式// 普通数据是获取不到的InputStream in = request.getInputStream();int len = 0;byte[] buffer = new byte[1024];while ((len = in.read(buffer)) > 0) {System.out.println(new String(buffer, 0, len));}}// 获取请求头private void test1(HttpServletRequest request) {System.out.println("---------获取请求头方式1-------------");// 拿到指定的请求头System.out.println(request.getHeader("cache-control"));System.out.println("---------获取请求头方式2-------------");// 拿到所有指定的请求头Enumeration e = request.getHeaders("cache-control");while (e.hasMoreElements()) {String headValue = (String) e.nextElement();System.out.println(headValue);}System.out.println("---------获取请求头方式3-------------");// 拿到所有请求头Enumeration e1 = request.getHeaderNames();while (e1.hasMoreElements()) {String headerName = (String) e1.nextElement();String headValue = request.getHeader(headerName);System.out.println(headerName + "=" + headValue);}}public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {doGet(request, response);}}

package test.request;public class User {private String[] username;public String[] getUsername() {return username;}public void setUsername(String[] username) {this.username = username;}public String getPassword() {return password;}public void setPassword(String password) {this.password = password;}private String password;}

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html>  <head>    <title>给RequestDemo2发送请求数据</title>  </head>    <body><!-- 浏览器可以通过两种方式向服务器发送请求数据      超链接方式后面跟了中文要经过url编码后再提交 --><a href="/day06/servlet/RequestDemo2?username=xxx">点点</a><br/>    <form action="/day06/servlet/RequestDemo2" method="post">    用户名1：<input type="text" name="username"/><br/>    用户名2：<input type="text" name="username"/><br/>    密码：<input type="password" name="password"/><br/>    <input type="submit" value="提交"/>    </form>  </body></html>

此程序还需用到commons-beanutils-1.9.0.jar和commons-logging-1.1.3.jar这两个jar包

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