apk、图片下载工具（1）

package com.js.ai.modules.pointwall.util;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;

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

/**
 *
 * @ClassName: ApkUtils
 * @Description: TODO 上传apk文件
 * @author:
 * @date:
 */

public class ApkUtils {
/**
 *
 * @Title: downloadCsv
 * @Description: TODO 下载apk
 * @param request
 * @param response
 * @param fileName
 * @throws Exception 

 * @return: void
 */
public static void download(HttpServletRequest request, HttpServletResponse response,String fileName ) throws Exception{

		response.setContentType("text/html;charset=UTF-8");
		BufferedInputStream in = null;
		BufferedOutputStream out = null;
		request.setCharacterEncoding("UTF-8");
		String rootpath = request.getSession().getServletContext().getRealPath("/");
		try {
			File f = new File(rootpath  + fileName);
			response.setContentType("application/x-excel");
			response.setCharacterEncoding("UTF-8");
			response.setHeader("Content-Disposition", "attachment; filename=" + fileName);
			response.setHeader("Content-Length", String.valueOf(f.length()));
			in = new BufferedInputStream(new FileInputStream(f));
			out = new BufferedOutputStream(response.getOutputStream());
			byte[] data = new byte[1024];
			int len = 0;
			while (-1 != (len = in.read(data, 0, data.length))) {
				out.write(data, 0, len);
			}
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			if (in != null) {
				in.close();
			}
			if (out != null) {
				out.close();
			}
		}
	}

     public static void  downloadImage(HttpServletRequest request, HttpServletResponse response,String fileName )throws Exception{
    	  //读取本地图片输入流
    	 request.setCharacterEncoding("UTF-8");
    	 response.setCharacterEncoding("UTF-8");
 		 String rootpath = request.getSession().getServletContext().getRealPath("/");
         FileInputStream inputStream = new FileInputStream(rootpath+fileName);
         int len= inputStream.available();
         //byte数组用于存放图片字节数据
         byte[] buff = new byte[len];
         inputStream.read(buff);
         //记得关闭输入流
         inputStream.close();
         //设置发送到客户端的响应内容类型
         response.setContentType("image/*");
         OutputStream out = response.getOutputStream();
         out.write(buff);
         //关闭响应输出流
         out.close();
    }
}