Response响应字节数据

Response响应字节数据

响应字节数据首先需要获取到自己输出流

ServletOutputStream outputStream = resp.getOutputStream();

然后通过字节输出流写数据

outputStream.write(字节数据);

现在我们通过自己输出流来将一张图片传到浏览器
准备的一张图片

package com.itheima.web.response;import org.apache.commons.io.IOUtils;import javax.servlet.ServletException;import javax.servlet.ServletOutputStream;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import java.io.FileInputStream;import java.io.IOException;import java.io.PrintWriter;/** * 响应字节数据：设置字节数据的响应体 */@WebServlet("/resp4")public class ResponseDemo4 extends HttpServlet {    @Override    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        //1. 读取文件        FileInputStream fis = new FileInputStream("E:\\java_project__\\request-demo\\src\\main\\java\\com\\itheima\\web\\response\\be.png");        //2. 获取response字节输出流        ServletOutputStream os = response.getOutputStream();        //3. 完成流的copy       /* byte[] buff = new byte[1024]; int len = 0; while ((len = fis.read(buff))!= -1){ os.write(buff,0,len); }*/        IOUtils.copy(fis,os);        fis.close();    }    @Override    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        this.doGet(request, response);    }}

==IOUtils.copy(fis,os);==该方法需要我们加入相关的依赖

        <dependency>            <groupId>commons-io</groupId>            <artifactId>commons-io</artifactId>            <version>2.6</version>        </dependency>