package cn.itcast.util;
import java.io.ByteArrayOutputStream;
import java.io.File;import java.io.FileInputStream;import java.io.IOException;import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;public class DownloadUtil {
/** * @param filePath 要下载的文件路径 * @param returnName 返回的文件名 * @param response HttpServletResponse * @param delFlag 是否删除文件 */ protected void download(String filePath,String returnName,HttpServletResponse response,boolean delFlag){ this.prototypeDownload(new File(filePath), returnName, response, delFlag); } /** * @param file 要下载的文件 * @param returnName 返回的文件名 * @param response HttpServletResponse * @param delFlag 是否删除文件 */ protected void download(File file,String returnName,HttpServletResponse response,boolean delFlag){ this.prototypeDownload(file, returnName, response, delFlag); } /** * @param file 要下载的文件 * @param returnName 返回的文件名 * @param response HttpServletResponse * @param delFlag 是否删除文件 */ public void prototypeDownload(File file,String returnName,HttpServletResponse response,boolean delFlag){ // 下载文件 FileInputStream inputStream = null; ServletOutputStream outputStream = null; try { if(!file.exists()) return; response.reset(); //设置响应类型 PDF文件为"application/pdf"，WORD文件为："application/msword"， EXCEL文件为："application/vnd.ms-excel"。 response.setContentType("application/octet-stream;charset=utf-8");//设置响应的文件名称,并转换成中文编码
//returnName = URLEncoder.encode(returnName,"UTF-8"); returnName = response.encodeURL(new String(returnName.getBytes(),"iso8859-1")); //保存的文件名,必须和页面编码一致,否则乱码 //attachment作为附件下载；inline客户端机器有安装匹配程序，则直接打开；注意改变配置，清除缓存，否则可能不能看到效果 response.addHeader("Content-Disposition", "attachment;filename="+returnName); //将文件读入响应流 inputStream = new FileInputStream(file); outputStream = response.getOutputStream(); int length = 1024; int readLength=0; byte buf[] = new byte[1024]; readLength = inputStream.read(buf, 0, length); while (readLength != -1) { outputStream.write(buf, 0, readLength); readLength = inputStream.read(buf, 0, length); } } catch (Exception e) { e.printStackTrace(); } finally { try { outputStream.flush(); } catch (IOException e) { e.printStackTrace(); } try { outputStream.close(); } catch (IOException e) { e.printStackTrace(); } try { inputStream.close(); } catch (IOException e) { e.printStackTrace(); } //删除原文件 if(delFlag) { file.delete(); } } }/**
* by tony 2013-10-17 * @param byteArrayOutputStream 将文件内容写入ByteArrayOutputStream * @param response HttpServletResponse 写入response * @param returnName 返回的文件名 */ public void download(ByteArrayOutputStream byteArrayOutputStream, HttpServletResponse response, String returnName) throws IOException{ response.setContentType("application/octet-stream;charset=utf-8"); returnName = response.encodeURL(new String(returnName.getBytes(),"iso8859-1")); //保存的文件名,必须和页面编码一致,否则乱码 response.addHeader("Content-Disposition", "attachment;filename=" + returnName); response.setContentLength(byteArrayOutputStream.size()); ServletOutputStream outputstream = response.getOutputStream(); //取得输出流 byteArrayOutputStream.writeTo(outputstream); //写到输出流 byteArrayOutputStream.close(); //关闭 outputstream.flush(); //刷数据 }}