JavaWeb学习总结（七）—HttpServletRequest

一、Request概述#

request是Servlet.service()方法的一个参数，类型为javax.servlet.http.HttpServletRequest。在客户端发出每个请求时，服务器都会创建一个request对象，并把请求数据封装到request中，然后在调用Servlet.service()方法时传递给service()方法，这说明在service()方法中可以通过request对象来获取请求数据。

二、Request的常用方法#

1.获取客户机的信息#

package com.web.study;

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;
/**
 * @author gacl
 * 通过request对象获取客户端请求信息
 */
public class Aservlet extends HttpServlet {

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        /**
         * 1.获得客户机信息
         */
        String requestUrl = request.getRequestURL().toString();//得到请求的URL地址
        String requestUri = request.getRequestURI();//得到请求的资源
        String queryString = request.getQueryString();//得到请求的URL地址中附带的参数
        String remoteAddr = request.getRemoteAddr();//得到来访者的IP地址
        String remoteHost = request.getRemoteHost();
        int remotePort = request.getRemotePort();
        String remoteUser = request.getRemoteUser();
        String method = request.getMethod();//得到请求URL地址时使用的方法
        String pathInfo = request.getPathInfo();
        String localAddr = request.getLocalAddr();//获取WEB服务器的IP地址
        String localName = request.getLocalName();//获取WEB服务器的主机名
        response.setCharacterEncoding("UTF-8");//设置将字符以"UTF-8"编码输出到客户端浏览器
        //通过设置响应头控制浏览器以UTF-8的编码显示数据，如果不加这句话，那么浏览器显示的将是乱码
        response.setHeader("content-type", "text/html;charset=UTF-8");
        PrintWriter out = response.getWriter();
        out.write("获取到的客户机信息如下：");
        out.write("<hr/>");
        out.write("请求的URL地址："+requestUrl);
        out.write("<br/>");
        out.write("请求的资源："+requestUri);
        out.write("<br/>");
        out.write("请求的URL地址中附带的参数："+queryString);
        out.write("<br/>");
        out.write("来访者的IP地址："+remoteAddr);
        out.write("<br/>");
        out.write("来访者的主机名："+remoteHost);
        out.write("<br/>");
        out.write("使用的端口号："+remotePort);
        out.write("<br/>");
        out.write("remoteUser："+remoteUser);
        out.write("<br/>");
        out.write("请求使用的方法："+method);
        out.write("<br/>");
        out.write("pathInfo："+pathInfo);
        out.write("<br/>");
        out.write("localAddr："+localAddr);
        out.write("<br/>");
        out.write("localName："+localName);
    }

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

}