response方法一览

最新推荐文章于 2024-01-31 17:40:21 发布

景天晓志

最新推荐文章于 2024-01-31 17:40:21 发布

阅读量832

点赞数

CC 4.0 BY-SA版权

分类专栏： JavaWeb

本文链接：https://blog.youkuaiyun.com/jingtian_xiaozhi/article/details/8122413

JavaWeb 专栏收录该内容

24 篇文章

订阅专栏

本文深入探讨了使用HTTP响应流输出中文、重定向页面至特定URL的技术细节，包括解决输出中文乱码问题的方法、使用getOutputStream进行数据输出及控制浏览器定时刷新的技巧。同时，介绍了如何通过响应头部设置实现文件下载、控制浏览器缓存策略，并展示了通过响应状态码实现页面重定向的应用场景。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

重定向，改变地址栏，用于购物栏

response.sendRedirect("/day06/index.jsp");

简单一练

package com.jingtian.controller;
  
import java.io.IOException;  
import java.io.OutputStream;  
import java.io.UnsupportedEncodingException;  
  
import javax.servlet.ServletException;  
import javax.servlet.http.HttpServlet;  
import javax.servlet.http.HttpServletRequest;  
import javax.servlet.http.HttpServletResponse;  
//在servlet用getOutputStream输出中文问题   
public class Out extends HttpServlet {  
  
    @Override  
    protected void doGet(HttpServletRequest req, HttpServletResponse response)  
            throws ServletException, IOException {  
        test1(response);  
    }  
  

    private void test1(HttpServletResponse response) throws IOException,  
    UnsupportedEncodingException {  
        String data="中国 ";  
        response.setHeader("Content-type", "text/html;charset=UTF-8");  
        OutputStream out=response.getOutputStream();  
        out.write(data.getBytes("UTF-8"));//字符转化成码表的时候查字节   
    }  
  
}

<pre class="java" name="code">package cn.itcast.response;

import java.io.IOException;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
//在servlet用getOutputStream输出中文问题
public class ResponseDemo1 extends HttpServlet {

	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse response)
			throws ServletException, IOException {
		test2(response);
	}

	private void test2(HttpServletResponse response) throws IOException,
			UnsupportedEncodingException {
		String data="中国2 ";
		//html: <meta>标签模拟一个http响应头
		OutputStream out=response.getOutputStream();
		//out.write(data.getBytes());
		out.write("<meta http-equiv='content-type' content='text/html;charset=UTF-8'>".getBytes());
		out.write(data.getBytes("UTF-8"));
	}
	private void test1(HttpServletResponse response) throws IOException,
	UnsupportedEncodingException {
		String data="中国 ";
		//程序以什么码表输出，一定要控制浏览器以什么码表打开
		response.setHeader("Content-type", "text/html;charset=UTF-8");
		OutputStream out=response.getOutputStream();
		//out.write(data.getBytes());
		out.write(data.getBytes("UTF-8"));//字符转化成码表的时候查字节
	}

}
</pre>
<br />

打印流，不常用

package cn.itcast.response;
//通过response的write流输出文字数据，不能输出电影等二进制流
import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
//在servlet用getOutputStream输出中文问题
public class ResponseDemo2 extends HttpServlet {

	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse response)
			throws ServletException, IOException {
		test1(response);
	}

	private void test2(HttpServletResponse response) throws IOException {
		String data="中国q";
		//该句代码等价于其后面两句
		response.setContentType("text/html;charset=GB2312");
		//response.setCharacterEncoding("GB2312");
		//response.setHeader("Content-type", "text/html;charset=ISO-8859-1");
		PrintWriter out=response.getWriter();
		out.write(data);//
	}
	private void test1(HttpServletResponse response) throws IOException {
		String data="中国q";
		//设置response使用的码表，以控制response以什么码表向浏览器输入数据,默认为ISO-8859-1
		response.setCharacterEncoding("GB2312");

		//指定浏览器以什么码表打开服务器发送的数据
		response.setHeader("Content-type", "text/html;charset=GB2312");

		PrintWriter out=response.getWriter();
		out.write(data);//
	}



}

文件下载

package cn.itcast.response;
//通过response实现文件下载
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
//
public class ResponseDemo3 extends HttpServlet {

	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse response)
			throws ServletException, IOException {

		test1(response);	
	}

	private void test2(HttpServletResponse response)
			throws FileNotFoundException, IOException {
		String path=this.getServletContext().getRealPath("/download/新图片.jpg");
		//C:\apache-tomcat-7.0.22\webapps\day06\download\新图片.jsp
		String filename=path.substring(path.lastIndexOf("\\")+1);
		
		InputStream in=null;
		OutputStream out=null;
		//如果下载文件是中文文件，则文件名需要经过url编码
		response.setHeader("content-disposition", "attachment;filename="+URLEncoder.encode(filename,"UTF-8"));
		try {
			in=new FileInputStream(path);
			int len=0;
			byte buffer[]=new byte[1024];
			out=response.getOutputStream();
			while((len=in.read(buffer))>0){
				out.write(buffer,0,len);
			}
		}finally{
			if(in!=null){
				try{
					
					in.close();
				}catch(Exception e){
					e.printStackTrace();
				}				
			}
		}
	}
	private void test1(HttpServletResponse response)
	throws FileNotFoundException, IOException {
		String path=this.getServletContext().getRealPath("/download/new.jpg");
		//C:\apache-tomcat-7.0.22\webapps\day06\download\new.jsp
		String filename=path.substring(path.lastIndexOf("\\")+1);
		
		InputStream in=null;
		OutputStream out=null;
		response.setHeader("content-disposition", "attachment;filename="+filename);
		

		try {
			in=new FileInputStream(path);
			int len=0;
			byte buffer[]=new byte[1024];
			out=response.getOutputStream();
			while((len=in.read(buffer))>0){
				out.write(buffer,0,len);
			}
		}finally{
			if(in!=null){
				try{
					
					in.close();
				}catch(Exception e){
					e.printStackTrace();
				}				
			}
		}
	}
}

控制浏览器定时刷新

package cn.itcast.response;
//定时刷新
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.Random;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class ResponseDemo5 extends HttpServlet {

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

		try {
			test3(request,response);
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

	private void test3(HttpServletRequest request,HttpServletResponse response) throws IOException, Exception {
		String message="<meta http-equiv='refresh' content='3;url=/day06/index.jsp'>登录成功，将在3秒后跳转，如果没有，请点<a href=''>超链接</a>";
		request.setAttribute("message",message);
		this.getServletContext().getRequestDispatcher("/message.jsp").forward(request, response);
	}
	private void test2(HttpServletResponse response) throws IOException {
		response.setHeader("refresh", "3;url='/day06/index.jsp'");
		String data = new Random().nextInt(100000)+"";
		response.getWriter().write("登录成功，将在3秒后跳转，如果没有，请点<a href=''>超链接</a>");
	}
	private void test1(HttpServletResponse response) throws IOException {
		response.setHeader("refresh", "3");
		String data = new Random().nextInt(100000)+"";
		response.getWriter().write(data);
	}

}

浏览器缓存

package cn.itcast.response;
//浏览器缓存
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.Random;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class ResponseDemo6 extends HttpServlet {

	@Override
	protected void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		String  data="aaaaa";
		response.setDateHeader("expires", System.currentTimeMillis()+3600*1000);
		response.getWriter().write(data);
			
	}


}

重定向

package cn.itcast.response;
//重定向
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.Random;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class ResponseDemo7 extends HttpServlet {

	@Override
	protected void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
	response.setStatus(302);
	response.setHeader("location", "/day06/index.jsp");
	response.sendRedirect("/day06/index.jsp");
			
	}


}