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");
		
	}

}