使用content-disposition响应头(服务器控制浏览器发下载方式打开文件)

package cn.itcast.web.http;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

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

public class Demo4 extends HttpServlet {
	public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
		
		//服务器控制浏览器以下载方式打开文件
		File file = new File("d:\\a.jpg");
		//注意位置，通常经况下，放在业务逻辑之前
		response.setHeader("content-disposition","attachment;filename="+file.getName());
		InputStream is = new FileInputStream(file);
		OutputStream os = response.getOutputStream();//对应浏览器的输出流
		byte[] buf = new byte[1024];
		int len = 0;
		while( (len=is.read(buf))>0 ){
			os.write(buf,0,len);
		}
		is.close();
		os.close();
	}
}