1 简介

web服务器收到客户端的http请求，会针对每一个请求，分别创建一个用于代表请求的request对象和代表响应的response对象。
request和response对象既然代表请求和响应，那么获取客户端提交的数据，只需要找request对象，而向容器输出对象，只需要找response对象。

2 HttpServletResponse

HttpServletResponse对象代表服务器的响应，这个对象中封装了向客户端发送数据、发送响应头、发送响应状态码的方法。

响应消息头：

public void addDateHeader(java.lang.String name,long date)

public void addHeader(java.lang.String name, java.lang.String value)

public void addIntHeader(java.lang.String name, int value)

public boolean containsHeader(java.lang.String name)

public void setHeader(java.lang.String name, java.lang.String value)

public void setIntHeader(java.lang.String name,int value)

public void setDateHeader(java.lang.String name,   long date)

响应消息正文：

public ServletOutputStream getOutputStream()  throws java.io.IOException

public java.io.PrintWriter getWriter() throws java.io.IOException

示例：字节流输出数据查本地码表

package com.servlet;

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

/**
 * 2017/11/5
 * 说明：
 */
public class ResponseDemo1 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String data = "我爱你";
        OutputStream out = response.getOutputStream();
        out.write(data.getBytes());//String 的getBytes()默认在windows系统中默认上的是GBK

    }

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

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
         version="3.1">

    <servlet>
        <servlet-name>ResponseDemo1</servlet-name>
        <servlet-class>com.servlet.ResponseDemo1</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>ResponseDemo1</servlet-name>
        <url-pattern>/responseDemo1</url-pattern>
    </servlet-mapping>
</web-app>

示例：字节流输出数据查UTF-8

package com.servlet;

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

/**
 * 2017/11/5
 * 说明：
 */
public class ResponseDemo1 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String data = "我爱你";
        OutputStream out = response.getOutputStream();
        out.write(data.getBytes("utf-8"));//String 的getBytes()默认在windows系统中默认上的是GBK

    }

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

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
         version="3.1">

    <servlet>
        <servlet-name>ResponseDemo1</servlet-name>
        <servlet-class>com.servlet.ResponseDemo1</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>ResponseDemo1</servlet-name>
        <url-pattern>/responseDemo1</url-pattern>
    </servlet-mapping>
</web-app>

解决方案：
- ①手动修改浏览器的码表为UTF-8（不建议） http://jingyan.baidu.com/article/d169e186a4e826436611d81e.html
- ②向客户端输出一个meta标签，模拟响应消息头 (不建议，这种方式目前好像只适合于IE)

<meta http-equiv='Content-Type' content='text/html;charset=UTF-8'>

package com.servlet;

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

/**
 * 2017/11/5
 * 说明：
 */
public class ResponseDemo1 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String data = "我爱你";
        OutputStream out = response.getOutputStream();
        out.write("<meta http-equiv='Content-Type' content='text/html;charset=UTF-8'>".getBytes());
        out.write(data.getBytes("utf-8"));//String 的getBytes()默认在windows系统中默认上的是GBK

    }

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

- ③向客户端输出响应消息头：response.setHeader("Content-Typt","text/html;charset=UTF-8");

package com.servlet;

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

/**
 * 2017/11/5
 * 说明：
 */
public class ResponseDemo1 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
       response.setHeader("Content-Type","text/html;charset=UTF-8");
        String data = "我爱你";
        OutputStream out = response.getOutputStream();

        out.write(data.getBytes("utf-8"));//String 的getBytes()默认在windows系统中默认上的是GBK

    }

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

- ④向客户端输出响应消息头：response.setContentType("text/html;charset=UTF-8");

package com.servlet;

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

/**
 * 2017/11/5
 * 说明：
 */
public class ResponseDemo1 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
       response.setContentType("text/html;charset=UTF-8");
        String data = "我爱你";
        OutputStream out = response.getOutputStream();

        out.write(data.getBytes("utf-8"));//String 的getBytes()默认在windows系统中默认上的是GBK

    }

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

示例：字符流输出中文内容

package com.servlet;

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

/**
 * 2017/11/5
 * 说明：
 */
public class ResponseDemo1 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        String data = "我爱你";
        PrintWriter out = response.getWriter();
        out.print(data);
    }

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

出现乱码，因为response对象是由Tomcat实现的，而Tomcat内部的码表是ISO8859-1。
改变字符流默认的编码：response.setCharacterEncoding("UTF-8");

package com.servlet;

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

/**
 * 2017/11/5
 * 说明：
 */
public class ResponseDemo1 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.setCharacterEncoding("UTF-8");

        String data = "我爱你";
        PrintWriter out = response.getWriter();
        out.print(data);
    }

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

因为：字符流是UTF-8，而浏览器本地的编码是GBK
修改浏览器本地的编码：response.setContentType("text/html;charset=UTF-8");

package com.servlet;

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

/**
 * 2017/11/5
 * 说明：
 */
public class ResponseDemo1 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.setCharacterEncoding("UTF-8");
        response.setContentType("text/html;charset=UTF-8");

        String data = "我爱你";
        PrintWriter out = response.getWriter();
        out.print(data);
    }

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

示例：；定时刷新

package com.servlet;

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

/**
 * 2017/11/5
 * 说明：
 */
public class ResponseDemo2 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.setHeader("refresh","2;URL=http://www.baidu.com");
    }

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

示例：控制缓存

package com.servlet;

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

/**
 * 2017/11/5
 * 说明：
 */
public class ResponseDemo3 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //清除缓存
        response.setHeader("expires","-1");
        response.setHeader("pragma","no-cache");
        response.setHeader("cache-control","no-cache");
    }

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

示例：请求重定向

package com.servlet;

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

/**
 * 2017/11/5
 * 说明：
 */
public class ResponseDemo3 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.setStatus(302);
        response.setHeader("location",request.getContextPath()+"/responseDemo2");

    }

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

package com.servlet;

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

/**
 * 2017/11/5
 * 说明：
 */
public class ResponseDemo3 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
       response.sendRedirect(request.getContextPath()+"/responseDemo2");

    }

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

3 HttpServletRequest

常用方法：

public java.lang.String getMethod()

public java.lang.String getRequestURI()

public java.lang.StringBuffer getRequestURL()

public java.lang.String getProtocol()

public java.lang.String getParameter(java.lang.String name)

public java.lang.String[] getParameterValues(java.lang.String name)

public java.util.Enumeration getParameterNames()

public java.util.Map getParameterMap()

public ServletInputStream getInputStream()

public java.lang.String getRemoteAddr()

示例：

package com.servlet;

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

/**
 * 2017/11/5
 * 说明：
 */
public class RequestServlet1 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.setCharacterEncoding("utf-8");
        response.setContentType("text/html;charset=utf-8");

        String method = request.getMethod();//获取请求方式
        String uri = request.getRequestURI();
        String url = request.getRequestURL().toString();
        String protocol = request.getProtocol();
        String ip = request.getRemoteAddr();//ip

        response.getWriter().println("方法："+method+"<br/>");
        response.getWriter().println("uri:"+uri+"<br/>");
        response.getWriter().println("url:"+url+"<br/>");
        response.getWriter().println("protocol:"+protocol+"<br/>");
        response.getWriter().println("ip:"+ip+"<br/>");

    }

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

示例：获取请求参数

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>注册</title>
</head>
<body>
<table>
    <form action="${pageContext.request.contextPath}/register" method="post">
        <tr>
            <td>用户名</td>
            <td>
                <input type="text" name="username"/>
            </td>
        </tr>
        <tr>
            <td>密码</td>
            <td>
                <input type="password" name="password"/>
            </td>
        </tr>
        <tr>
            <td>爱好</td>
            <td>
                <input type="checkbox" name="hobby" value="游戏"/>游戏
                <input type="checkbox" name="hobby" value="开发"/>开发
                <input type="checkbox" name="hobby" value="电视"/>电视
            </td>
        </tr>
        <tr>
            <td colspan="2">
                <input type="submit" value="注册"/>
            </td>
        </tr>

    </form>
</table>
</body>
</html>

package com.servlet;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Arrays;

/**
 * 2017/11/5
 * 说明：
 */
public class RegisterServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String username = request.getParameter("username");
        String password = request.getParameter("password");
        String[] hobby = request.getParameterValues("hobby");
        System.out.println("用户名："+username);
        System.out.println("密码："+password);
        System.out.println("爱好："+ Arrays.toString(hobby));
    }

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

示例：post请求

package com.servlet;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Arrays;

/**
 * 2017/11/5
 * 说明：
 */
public class RegisterServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.setCharacterEncoding("utf-8");
        String username = request.getParameter("username");
        String password = request.getParameter("password");
        String[] hobby = request.getParameterValues("hobby");
        System.out.println("用户名："+username);
        System.out.println("密码："+password);
        System.out.println("爱好："+ Arrays.toString(hobby));
    }

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

通过request.setCharacterEncoding("utf-8") 设置请求消息内容的编码为utf-8

示例：get请求

package com.servlet;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Arrays;

/**
 * 2017/11/5
 * 说明：
 */
public class RegisterServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        String username = request.getParameter("username");
        String password = request.getParameter("password");
        String[] hobby = request.getParameterValues("hobby");
        System.out.println("用户名："+username);
        System.out.println("密码："+password);
        System.out.println("爱好："+ Arrays.toString(hobby));
    }

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

注意：Tomcat8.0以上的版本使用的编码是UTf-8，所以不需要改变手动转换，如果是Tomcat8.0以下的。就需要手动装换了。

Request和Response的更多相关文章

Request 和 Response 原理
* Request 和 Response 原理: * request对象和response对象由服务器创建,我们只需要在service方法中使用这两个对象即可 * 继承体系结构: ...
Request 、Response 与Server的使用
纯属记录总结,以下图片都是来自 ASP.NET笔记之 Request .Response 与Server的使用 Request Response Server 关于Server.MapPath 方法看 ...
request 和response
当今web程序的开发技术真是百家争鸣,ASP.NET, PHP, JSP,Perl, AJAX 等等. 无论Web技术在未来如何发展,理解Web程序之间通信的基本协议相当重要, 因为它让我们理解了We ...
Request和Response对象
Request 和 Response 对象起到了服务器与客户机之间的信息传递作用.Request 对象用于接收客户端浏览器提交的数据,而 Response 对象的功能则是将服务器端的数据发送到客户端浏 ...
Java 中的 request 和response 理解
request和response(请求和响应) 1.当Web容器收到客户端的发送过来http请求,会针对每一次请求,分别创建一个用于代表此次请求的HttpServletRequest对象(reque ...
【转】request和response的页面跳转传参
下面是一位园友的文章: jsp或Servlet都会用到页面跳转,可以用 request.getRequestDispatcher("p3.jsp").forward(request ...
LoadRunner中取Request、Response
LoadRunner中取Request.Response LoadRunner两个“内置变量”: 1.REQUEST,用于提取完整的请求头信息. 2.RESPONSE,用于提取完整的响应头信息. 响应 ...
Spring mvc中使用request和response
@ResponseBody @RequestMapping(value="/ip", method=RequestMethod.GET) public String getIP(H ...
springMVC获取request和response
转载:http://blog.sina.com.cn/s/blog_7085382f0102v9jg.html 1.参数例如: @RequestMapping("/test") ...
ASP.NET中的Request、Response、Server对象
Request对象 Response.Write(Request.ApplicationPath) //应用根路径 Request.AppRelativeCurrentExecutionFilePat ...

随机推荐

前端工程化webpack（一）
webpack 的基本用法 1.app.js 引入模块 import moduleLog from './module.js' //引入moduleLog从./module.js 2.module ...
Java之CountDownLatch ---控制线程执行顺序
一,类介绍这是java.util.concurrent包里的一个同步辅助类,它有两个主要的常用方法 countDown()方法以及await()方法.在完成一组正在其他线程中执行的操作之前,它允许 ...
【Spring】DispatcherServlet源码分析
使用过HttpServlet的都应该用过其doGet和doPost方法,接下来看看DispatcherServlet对这两个方法的实现(源码在DispatcherServlet的父类Framework ...
Oracle实战笔记（第二天）
导读今日主要内容:表管理.表操作(增删改查).表查询(简单查询&复杂查询).创建数据库. 一.表管理 1.表命名规范必须以字母开头: 长度不能超过30个字符: 不能使用Oracle保留字: ...
我的第五个网页制作：pre、html转义、abbr标签的使用
<!doctype html> <html> <head> <meta charset="utf-8"> <title> ...
北京师范大学校赛C
https://www.nowcoder.com/acm/contest/submit/0dff89ad7b8444719df155d507f3e1dd?ACMContestId=3&tagI ...
2017ecjtu-summer training #5 UVA10382
题意问最少可用几个圆覆盖矩形区域. 解析将圆形转换成矩形有效区域,直径小于等于宽度的圆不考虑,从而转化成区间覆盖问题,然后贪心出最少圆. 贪心思想每次选择出区域左界比上次选出的区域右界小的且区域 ...
WERTYU（getchar()用法）
题目连接:http://acm.tju.edu.cn/toj/showp.php?pid=13681368. WERTYU Time Limit: 1.0 Seconds Memory Lim ...
应用中Token的作用
Token 的作用 Token,就是令牌,最大的特点就是随机性,不可预测.一般黑客或软件无法猜测出来. 那么,Token有什么作用?又是什么原理呢? Token一般用在两个地方: 1)防止表单重复提交 ...
4层板的pcb创建
四层板的制作可以在原先的二层板上增加层,(软件为AD17)方法如下: 一.单击Design->Layer Stack Manager菜单(快捷键为DK),将弹出以下的界面: 二,选择上图中的Ad ...

Request和Response

1 简介

2 HttpServletResponse

3 HttpServletRequest

Request和Response的更多相关文章

随机推荐

热门专题