servlet通过响应头Content-Disposition实现文件下载效果

package day08;

import java.io.File;

import java.io.FileInputStream;

import java.io.IOException;

import java.io.OutputStream;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

/**

 * 案例【Content-Disposition】-- attachment; filename=aaa.zip

 * @author Administrator

 *  文件下载效果

 */

public class ResponseDemo05 extends HttpServlet {

	private static final long serialVersionUID = 4407828089924059971L;

	public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

		/*

		request.setCharacterEncoding("utf-8");

		response.setContentType("image/png;charset=utf-8");

		// 1) 读取本地文件

		FileInputStream in = new FileInputStream("e:/picture.png");

		// 2) 写出给浏览器（字节内容）

		OutputStream out = response.getOutputStream();

		byte[] buf = new byte[1024];

		int len = 0;

		// 边读边写

		while( (len=in.read(buf)) != -1) {

			out.write(buf, 0, len);

		}

		// 关闭

		in.close();

		out.close();

		*/

		/**

		 * 但是我们是想让浏览器把这张图片以下载的方式打开

		 */

		request.setCharacterEncoding("utf-8");

		response.setContentType("text/html;charset=utf-8");

		File file = new File("e:/图片.png");//                                中文的图片名的话，必须这样进行包装     先通过GBK进行getBytes，然后通过设置新的ISO8859_1

		response.setHeader("content-disposition", "attachment;filename="+new String(file.getName().getBytes("GBK"),"ISO8859_1"));

		// 1) 读取本地文件

		FileInputStream in = new FileInputStream(file);

		// 2) 写出给浏览器（字节内容）

		OutputStream out = response.getOutputStream();

		byte[] buf = new byte[1024];

		int len = 0;

		// 边读边写

		while( (len=in.read(buf)) != -1) {

			out.write(buf, 0, len);

		}

		// 关闭

		in.close();

		out.close();

	}

	public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

		request.setCharacterEncoding("utf-8");

		response.setContentType("text/html;charset=utf-8");

	}

}