• servlet中关于下载


    package com.huawei.response;

    import java.io.BufferedInputStream;
    import java.io.IOException;
    import java.io.InputStream;
    import java.io.OutputStream;
    import java.io.PrintWriter;
    import java.util.Date;

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

    /**
    * @author Administrator
    * 测试Response
    */
    public class TestResponse01 extends HttpServlet{

    /**
    *
    */
    private static final long serialVersionUID = 6682298499488718112L;

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp)
    throws ServletException, IOException {
    this.doPost(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp)
    throws ServletException, IOException {
    //业务逻辑
    //this.testAddOrSetHeader(req, resp);
    //this.testWriteSomething(req, resp);
    this.testOutputStream(req, resp);
    }

    protected void testAddOrSetHeader(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException {
    //写一个头信息到 浏览器中
    //可以为同一个名字的键添加多个值
    resp.addHeader("test-test", "sxt-sxt");
    resp.addHeader("test-test", "sxt-sxt1");
    //修改同名的值 或是添加头信息
    resp.setHeader("cdsxt", "cdsxt");
    resp.setHeader("cdsxt", "cdsxt1");

    //对setHeader的封装
    resp.setDateHeader("now", new Date().getTime());
    try {
    Thread.currentThread().sleep(1000);
    } catch (InterruptedException e) {
    e.printStackTrace();
    }
    resp.setDateHeader("now", new Date().getTime());
    }


    protected void testWriteSomething(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException {

    //得到输出器
    //告诉浏览器应该怎样去处理当前这一段内容
    resp.setContentType("text/html;charset=utf-8");
    PrintWriter writer = resp.getWriter();

    // writer.write("<h1>TestResponse!!!!</h1>");
    writer.write("<!DOCTYPE html>");
    writer.write("<html>");
    writer.write("<head>");
    writer.write("<title>Test Response</title>");
    writer.write("<script>alert('this is a test response')</script>");
    writer.write("</head>");
    writer.write("<body>");
    if(req.getParameter("name")!=null){
    writer.write("<h1 style="color:green;">name have value</h1>");
    }else{
    writer.write("<h1 style="color:red;">name is null</h1>");
    }
    writer.write("<img src="1.jpg">");
    writer.write("</body>");
    writer.write("</html>");
    }

    /**
    * 测试输出流
    * @param req
    * @param resp
    * @throws ServletException
    * @throws IOException
    */
    protected void testOutputStream(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException {

    resp.setContentType("image/jpeg");

    //文件下载的头
    //关于名字乱码的问题 名字的编码格式 只支持一种 ISO8859-1 需要的注意的是 得到字符串byte数组的时候 要指定GBK(兼容IE)编码
    resp.setHeader("Content-Disposition", "attachment; filename=""+new String("测试测测侧擦擦大苏打.jpg".getBytes("GBK"),"ISO8859-1")+""");

    //得到输出流
    OutputStream out = resp.getOutputStream();
    //得到文件的输入流
    InputStream in = this.getClass().getClassLoader().getResourceAsStream("1.jpg");

    byte []bytes = new byte[1024*8];
    int len = 0;
    while((len = in.read(bytes))!=-1){
    out.write(bytes, 0, len);
    }

    out.flush();
    in.close();
    out.close();

    }

    }

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  • 原文地址:https://www.cnblogs.com/hwgok/p/5803756.html
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