response的基本知识
HttpServlet
Web服务器收到客户端的http请求，会针对每一次请求，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对象即代表了请求和响应，那我们要获取客户机提交过来的数据，只需要找request对象就可以了，要想客户机输出数据，只需要找response即可。
response只是一个对象名称，HttpServletResponse类
Student ?xiaoming=new Student(); ? 类名: Student ? ? ? 对象名:xiaoming
重定向:重新制定访问的方向
作用:用于从一个Servlet去开启另一个Servlet重定向:
重定向属于浏览器跳转，不是服务器自己跳转 ? ?超链接是一样的
重定向跳转页面浏览器地址会发生变化
重定向为两次请求
an重定向可以访问不同服务器的页面跳转
package com.Servlet;
import java.awt.image.RescaleOp;
import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* Servlet implementation class Servlet1
*/
@WebServlet("/Servlet1")
public class Servlet1 extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public Servlet1() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// response 回复 当浏览器根据地址发送请求servlet.servlet
//使用response对象回复对象
//设置servlet发送的数据支撑HTML格式
response.setContentType("text/html");
//设置发送servlet 浏览html格式 utf-8
response.setCharacterEncoding("UTF-8");
//response 回复 内容/数据/消息
String info="hellow world java";
String info1="<h1>你好,倒计时servlet<span style='color:red'> java jsp</span></h1>";
//使用response获得输出
OutputStream os =response.getOutputStream();
os.write(info.getBytes());
os.write(info1.getBytes());
}
/*
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*
*/
}
package com.Servlet;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* Servlet implementation class Servlet2
*/
@WebServlet("/Servlet2")
public class Servlet2 extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public Servlet2() {
super();
//
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
//设置servlet发送的数据支撑HTML格式
response.setContentType("text/html");
//设置发送servlet 浏览html格式 utf-8
response.setCharacterEncoding("UTF-8");
String info="abc";
String info1="20软件三班";
String info2="你好,<div style='color:red;background-Color:green'> <h1 style='color:red;background-Color:blue'>"
+ "java jsp</h1>"
+"<ul><li>1111</li><br><li>2111</li><br><li>3111</li><br></ul>"
+"<ol><li>1111</li><br><li>2111</li><br><li>3111</li><br></ol>"
+"<hr>"
+"<table style='color:red;background-Color:yellow'>课表"
+ "<th>4</th><tr><td>1</td><td>2</td><td>3<td/><tr/>"
+"<th>2</th>4<tr><td>5</td><td>6</td><td>7<td/><tr/>"
+ "</table>"
+"<hr>"
+"<hr>"
+"<h1>hellow world see you </h1>"
+ "</div>";
//将数据写出的
PrintWriter pw=response.getWriter();
pw.print(info);
pw.print(info1);
pw.print(info2);
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}
package com.Servlet;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* Servlet implementation class Servlet3
*/
@WebServlet("/Servlet3")
public class Servlet3 extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
* 图片的下载
*/
public Servlet3() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// 使用对象完成图片的下载
//设置servlet发送的数据支撑HTML格式
response.setContentType("text/html");
//设置发送servlet 浏览html格式 utf-8
response.setCharacterEncoding("UTF-8");
//设置响应头
response.setHeader("content-disposition", "attachment;filenname=flower.jpg");
ServletContext sa=getServletContext();
String path=sa.getRealPath("/imges/yu.png");
InputStream is =new FileInputStream(path);
byte [] bytes =new byte[1024];
int count=-1;
OutputStream os=response.getOutputStream();
while((count=is.read(bytes))!=-1) {
os.write(bytes,0,count);
}
//response.getWriter().append("Served at: ").append(request.getContextPath());
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}
package com.Servlet;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.util.Random;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* Servlet implementation class Servlet4
*/
@WebServlet("/Servlet6")
public class Servlet4 extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public Servlet4() {
super();
System.out.println("Servlet4正在运行中");
// 创建码
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// 生成数字，随机数
//100000 -1000000
//[0,1]*900000=[0,900000]+100000
response.setCharacterEncoding("UTF-8");
response.setContentType("text/html");
response.setHeader("refresh", "5");
//设置要求浏览器
/* response.sendRedirect("Servlet1"); */
int i=(int)(Math.random()*900000+100000);
int a=(int)(Math.random()*9000+1000);
int c=(int)(Math.random()*900+100);
System.out.println("@@@@"+(new Random().nextInt(900000)+100000));
/*
* 设置随机
*/
System.out.println(new Random().nextInt(100));
System.out.println(Math.random());
PrintWriter pw =response.getWriter();
pw.print("你的支付宝到账1000万元，需要的码号为:<h1 style='color:red ;background-color:green'>"+i+"</h1>,打死也不说 \"<hr>\";");
pw.print("你的QQ到账1000万元，需要的码号为:<h2 style='color:red ;background-color:green'>"+c+"</h2>,打死也不说 \"<hr>\";");
pw.print("你的微信到账1000万元，需要的码号为:<span style='color:green'>"+a+"</span>,打死也不说");
pw.print("你的手机支付宝到账1000万<span style='color :red'>"+i+"</span>");
}
/*response.sendRedirect("Servlet1");
try { Thread.sleep(5000);
Connection conn = Time.time();
} catch (Exception e)
{
e.printStackTrace();
response.sendRedirect("Servlet1");
}
}
*/
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse
* response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}
package com.Servlet;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* Servlet implementation class Servlet5
*/
@WebServlet("/Servlet5")
public class Servlet5 extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public Servlet5() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//当浏览器访问servlet5时刻，servlet5回复消息访问servlet1
System.out.println("servlet5回复消息访问servlet1");
response.sendRedirect("Servlet1");
}
/*
* // TODO Auto-generated method stub
* response.getWriter().append("Served at: ").append(request.getContextPath());
* }
*/
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}
package com.Servlet;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.util.Random;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* Servlet implementation class Servlet4
*/
@WebServlet("/Servlet6")
public class Servlet6 extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public Servlet6() {
super();
System.out.println("Servlet6正在运行中");
// 创建码
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// 生成数字，随机数
//100000 -1000000
//[0,1]*900000=[0,900000]+100000
response.setCharacterEncoding("UTF-8");
response.setContentType("text/html");
response.setHeader("refresh", "5");
//设置要求浏览器
/* response.sendRedirect("Servlet1"); */
int i=(int)(Math.random()*900000+100000);
int a=(int)(Math.random()*9000+1000);
int c=(int)(Math.random()*900+100);
System.out.println("@@@@"+(new Random().nextInt(900000)+100000));
/*
* 设置随机
*/
System.out.println(new Random().nextInt(100));
System.out.println(Math.random());
PrintWriter pw =response.getWriter();
pw.print("你的支付宝到账1000万元，需要的码号为:<h1 style='color:red ;background-color:green'>"+i+"</h1>,打死也不说 \"<hr>\";");
pw.print("你的QQ到账1000万元，需要的码号为:<h2 style='color:red ;background-color:green'>"+c+"</h2>,打死也不说 \"<hr>\";");
pw.print("你的微信到账1000万元，需要的码号为:<span style='color:green'>"+a+"</span>,打死也不说");
pw.print("你的手机支付宝到账1000万<span style='color :red'>"+i+"</span>");
response.sendRedirect("Servlet1");
try { Thread.sleep(5000);
Connection conn = Time.time();
} catch (Exception e)
{
e.printStackTrace();
/* response.sendRedirect("Servlet1"); */
}
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}
package com.Servlet;
import java.sql.Connection;
public class Time {
public static int time=60*60*60;
static Connection time() {
while (time>0) {
time--;
try {
Thread.sleep(1000);
int hh=time/1/1%1;
int mm=time/60%1;
int ss=time%6;
if(hh==0 &&mm==0 && ss==0) {
break;
}
System.out.println("小时"+hh+"С?"+mm+"分钟"+ss+"秒");
} catch (InterruptedException e) {
// TODO: handle exception
}finally {
System.out.println("正在跳转页面哦 Servlect1");
}
}
return null;
}
public static void main(String[] args) {
// TODO Auto-generated method stub
time();
}
}
运行结果
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?总结：response对象的作用
图片，音频，文件的下载
对浏览器的访问
随机码的获取
servlet的跳转
HttpServlet
HttpRequest的有关方法，获取HTTP请求信息；
HttpRequest的有关方法，获取HTTP请求信息；
// 生成数字，随机数
//100000 -1000000
//[0,1]*900000=[0,900000]+100000
response.setCharacterEncoding("UTF-8");
response.setContentType("text/html");
//设置要求浏览器?
response.setHeader("refresh", "10");
//response 重定向 重新指定访问方向
从一个servlet 去 开启 新的servlet
重定向：属于浏览器的跳转.超链接
<a href=""></a>
浏览地址发生改变
重定向为二次请求。
重定向可以访问不同服务器的跳转。