Request获取请求数据实例

Table of Contents

原理

继承体系

数据格式

获取请求数据

获取请求行数据

获取请求头数据

Post方式获取请求体

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原理

Request是tomcat创建的对象，请求过来的时候，tomcat创建Request封装请求，实际上是RequestFacade

继承体系

HttpServletRequest接口继承ServletRequest接口，

 RequestFacade实现了HttpServletRequest

数据格式

• 请求行
• 请求头
• 请求空行
• 请求体

获取请求数据

获取请求行数据

• 获取请求方式：String getMethod()
• 获取虚拟目录：String getContextPath()
• 获取Servlet路径：String getServletPath()
• 获取get方式请求参数：String getQueryString()
• 获取请求URI：String getRequestURI()
• 获取请求URL：StringBuffer getRequestURL()
• 获取协议版本：String getProtocol()
• 获取客户机的IP地址：String getRemoteAddr()

package com.lingaolu.request;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.*;
import java.io.IOException;

/**
 * @author 林高禄
 * @create 2020-07-07-10:52
 */
@WebServlet("/requestDemo1")
public class RequestDemo1 extends HttpServlet {

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    }

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        System.out.println("请求方式: "+request.getMethod());
        System.out.println("虚拟目录: "+request.getContextPath());
        System.out.println("Servlet路径: "+request.getServletPath());
        System.out.println("get方式请求参数: "+request.getQueryString());
        System.out.println("请求URI: "+request.getRequestURI());
        System.out.println("请求URL: "+request.getRequestURL().toString());
        System.out.println("协议及版本:"+request.getProtocol());
        System.out.println("客户机的IP地址: "+request.getRemoteAddr());

    }
}

Postman请求访问

 

后台输出

请求方式: GET
虚拟目录: /myRequest
Servlet路径: /requestDemo1
get方式请求参数: name=lin&age=23
请求URI: /myRequest/requestDemo1
请求URL: http://localhost:8080/myRequest/requestDemo1
协议及版本:HTTP/1.1
客户机的IP地址: 0:0:0:0:0:0:0:1

获取请求头数据

• Enumeration<String> getHeaderNames()：获取所有的请求头名称
• String getHeader(String var1)：通过请求头的名称获取请求头的值

package com.lingaolu.request;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.*;
import java.io.IOException;
import java.util.Enumeration;

/**
 * @author 林高禄
 * @create 2020-07-07-10:52
 */
@WebServlet("/requestDemo2")
public class RequestDemo2 extends HttpServlet {

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    }

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        Enumeration<String> headerNames = request.getHeaderNames();
        while(headerNames.hasMoreElements()){
            String name = headerNames.nextElement();
            String header = request.getHeader(name);
            System.out.println(name+" ："+header);
        }

    }
}

通过Postman请求

后台输出

cache-control ：no-cache
postman-token ：95bc6857-e84c-4073-86bb-9a8e5dedd6a2
user-agent ：PostmanRuntime/7.6.0
accept ：*/*
host ：localhost:8080
accept-encoding ：gzip, deflate
connection ：keep-aliv

Post方式获取请求体

• BufferedReader getReader()：获取字符输入流，只能操作字符数据
• ServletInputStream getInputStream()：获取字节输入流，可以操作所有类型选数据

package com.lingaolu.request;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.*;
import java.io.BufferedReader;
import java.io.IOException;

/**
 * @author 林高禄
 * @create 2020-07-07-10:52
 */
@WebServlet("/requestDemo1")
public class RequestDemo1 extends HttpServlet {

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        BufferedReader reader = request.getReader();
        String line = null;
        while((line = reader.readLine())!= null){
            System.out.println(line);
        }
    }

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        System.out.println("请求方式: "+request.getMethod());
        System.out.println("虚拟目录: "+request.getContextPath());
        System.out.println("Servlet路径: "+request.getServletPath());
        System.out.println("get方式请求参数: "+request.getQueryString());
        System.out.println("请求URI: "+request.getRequestURI());
        System.out.println("请求URL: "+request.getRequestURL().toString());
        System.out.println("协议及版本:"+request.getProtocol());
        System.out.println("客户机的IP地址: "+request.getRemoteAddr());

    }
}

用Postman请求

后台输出:

name=lin&age=27

可见，get请求和post请求，获取请求参数的方式不一样，下面就介绍一种异样的方式