HttpServletRequest

时间 2019-11-12

标签 httpservletrequest 繁體版

原文原文链接

HttpServletRequest概述：html

service方法中的request的类型是ServletRequest，而doGet/doPost方法的request的类型是HttpServletRequest，HttpServletRequest是ServletRequest的子接口。java

request的运行流程

经过request得到请求行：oracle

package com.oracle.demo01;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class LineServlet extends HttpServlet {

    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //获取请求方式
        System.out.println("请求方式为"+request.getMethod());
        //获取请求URI
        System.out.println("URI为"+request.getRequestURI());
        //获取请求URL
        System.out.println("URL为"+request.getRequestURL());
        //获取WEB应用名称
        System.out.println("WEB应用名称为"+request.getContextPath());
        //获取get请求后URL后的字符串
        System.out.println("get请求参数为"+request.getQueryString());
        //获取客户端的ip地址
        System.out.println("ip地址为"+request.getRemoteAddr());
        
    }

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

运行结果：post

package com.oracle.demo01;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class RefereServlet extends HttpServlet {

    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //获取refer头
        String refere=request.getHeader("Referer");
        String content=null;
        if(refere.startsWith("http://localhost:8080")){
            content="真的离婚了！";
        }else{
            content="你是小偷！";
        }
        //解决response中文乱码
        response.setContentType("text/html;charset=utf-8");
        response.getWriter().write(content);
    }

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

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
    <a href="/WEB06/RefereServlet">宋仲基和宋慧乔分手了</a>
</body>
</html>

经过request得到请求体：性能

package com.oracle.demo01;

import java.io.IOException;
import java.util.Map;
import java.util.Set;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class BodyServlet extends HttpServlet {

    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //post请求解决中文乱码问题
        //request.setCharacterEncoding("utf-8");
        //获取请求参数
        //1.获取单个值的参数
        String name=request.getParameter("username");
        name=new String(name.getBytes("ISO-8859-1"), "UTF-8");
        String sex=request.getParameter("sex");
        sex=new String(sex.getBytes("ISO-8859-1"), "UTF-8");
        System.out.println(name+"..."+sex);
        //2.获取多个值
        String[] hobbys=request.getParameterValues("hobby");
        //遍历
        for(String s:hobbys){
            System.out.println(s);
        }
        //3.获取全部的请求参数Map
        Map<String, String[]> map=request.getParameterMap();
        //遍历
        Set<String> set=map.keySet();
        for(String str:set){
            String[] value=map.get(str);
            for(String v:value){
                System.out.println(str+"..."+v);
            }
        }
    }

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

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
    <form action="/WEB06/BodyServlet" method="get">
        <input type="text" name="username"><br>
        <input type="radio" name="sex" value="man">男
        <input type="radio" name="sex" value="woman">女
        <br>
        <input type="checkbox" name="hobby" value="ppq">
        乒乓球
        <input type="checkbox" name="hobby" value="pq">
        排球
        <input type="checkbox" name="hobby" value="wq">
        网球
        <br>
        <input type="submit" value="提交">
    </form>
</body>
</html>

request是一个域对象网站

package com.oracle.demo02;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class Servlet01 extends HttpServlet {

    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //向request域中存值
        request.setAttribute("name", "袁一鸣");
        //请求转发
        request.getRequestDispatcher("/Servlet02").forward(request, response);
    }

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

package com.oracle.demo02;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;


public class Servlet02 extends HttpServlet {

    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //从request域中取值
        String name=(String)request.getAttribute("name");
        response.setContentType("text/html;charset=utf-8");
        response.getWriter().write("hello"+name);
    }

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

运行结果：ui

request生命周期：spa

建立：访问时建立requestcode

销毁：响应结束request销毁orm

域的做用范围：一次请求中

转发与重定向的区别:

1）重定向两次请求，转发一次请求

2）重定向地址栏的地址变化，转发地址不变

3）从新定向能够访问外部网站转发只能访问内部资源

4）转发的性能要优于重定向

1. HttpServletRequest
2. httpservletrequest
3. Request (HttpServletRequest)
4. Servlet——HttpServletRequest
5. HttpServletRequest get
6. HttpServletRequest类
7. javaweb-HttpServletRequest
8. HttpServletRequest参数获取，HttpServletRequest详解
9. HttpServletRequest概述
10. spring HttpServletRequest 简介
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