1:浏览器请求下载
public void listStockcodeUplaod(HttpServletRequest req,
HttpServletResponse res) throws Exception {
String urlPath = req.getParameter("url");
String name = req.getParameter("name"); URL url = new URL(urlPath);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
// 设置超时间为3秒
conn.setConnectTimeout(10 * 1000);
// 防止屏蔽程序抓取而返回403错误
// conn.setRequestProperty("User-Agent",
// "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)"); // 得到输入流
InputStream inputStream = conn.getInputStream();
// 获取自己数组
byte[] getData = new byte[1024];
int len = 0;
ByteArrayOutputStream bos = new ByteArrayOutputStream();
while ((len = inputStream.read(getData)) != -1) {
bos.write(getData, 0, len);
}
bos.close();
getData = bos.toByteArray(); // 以流的形式下载文件。
// byte[] buffer = new byte[fis.available()];
inputStream.read(getData);
inputStream.close();
// 清空response
res.reset();
// 设置response的Header
res.addHeader("Content-Disposition", "attachment;filename=sss.pdf");
res.addHeader("Content-Length", "" + getData.length);
OutputStream toClient = new BufferedOutputStream(res.getOutputStream());
res.setContentType("application/octet-stream");
toClient.write(getData);
toClient.flush();
toClient.close(); System.out.println("info:" + url + " download success");
}
2.同上
public HttpServletResponse download(String path, HttpServletResponse response) {
try {
// path是指欲下载的文件的路径。
File file = new File(path);
// 取得文件名。
String filename = file.getName();
// 取得文件的后缀名。
String ext = filename.substring(filename.lastIndexOf(".") + 1).toUpperCase();
// 以流的形式下载文件。
InputStream fis = new BufferedInputStream(new FileInputStream(path));
byte[] buffer = new byte[fis.available()];
fis.read(buffer);
fis.close();
// 清空response
response.reset();
// 设置response的Header
response.addHeader("Content-Disposition", "attachment;filename=" + new String(filename.getBytes()));
response.addHeader("Content-Length", "" + file.length());
OutputStream toClient = new BufferedOutputStream(response.getOutputStream());
response.setContentType("application/octet-stream");
toClient.write(buffer);
toClient.flush();
toClient.close();
} catch (IOException ex) {
ex.printStackTrace();
}
return response;
}
public void downloadLocal(HttpServletResponse response) throws FileNotFoundException {
// 下载本地文件
String fileName = "Operator.doc".toString(); // 文件的默认保存名
// 读到流中
InputStream inStream = new FileInputStream("c:/Operator.doc");// 文件的存放路径
// 设置输出的格式
response.reset();
response.setContentType("bin");
response.addHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\"");
// 循环取出流中的数据
byte[] b = new byte[100];
int len;
try {
while ((len = inStream.read(b)) > 0)
response.getOutputStream().write(b, 0, len);
inStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
public void downloadNet(HttpServletResponse response) throws MalformedURLException {
// 下载网络文件
int bytesum = 0;
int byteread = 0;
URL url = new URL("windine.blogdriver.com/logo.gif");
try {
URLConnection conn = url.openConnection();
InputStream inStream = conn.getInputStream();
FileOutputStream fs = new FileOutputStream("c:/abc.gif");
byte[] buffer = new byte[1204];
int length;
while ((byteread = inStream.read(buffer)) != -1) {
bytesum += byteread;
System.out.println(bytesum);
fs.write(buffer, 0, byteread);
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
3.支持在线打开文件的一种方式
public void downLoad(String filePath, HttpServletResponse response, boolean isOnLine) throws Exception {
File f = new File(filePath);
if (!f.exists()) {
response.sendError(404, "File not found!");
return;
}
BufferedInputStream br = new BufferedInputStream(new FileInputStream(f));
byte[] buf = new byte[1024];
int len = 0;
response.reset(); // 非常重要
if (isOnLine) { // 在线打开方式
URL u = new URL("file:///" + filePath);
response.setContentType(u.openConnection().getContentType());
response.setHeader("Content-Disposition", "inline; filename=" + f.getName());
// 文件名应该编码成UTF-8
} else { // 纯下载方式
response.setContentType("application/x-msdownload");
response.setHeader("Content-Disposition", "attachment; filename=" + f.getName());
}
OutputStream out = response.getOutputStream();
while ((len = br.read(buf)) > 0)
out.write(buf, 0, len);
br.close();
out.close();
}
4 url下载到本地
/**
* 从网络Url中下载文件
* @param urlStr
* @param fileName
* @param savePath
* @throws IOException
*/
public static void downLoadFromUrl(String urlStr,String fileName,String savePath) throws IOException{
URL url = new URL(urlStr);
HttpURLConnection conn = (HttpURLConnection)url.openConnection();
//设置超时间为3秒
conn.setConnectTimeout(3*1000);
//防止屏蔽程序抓取而返回403错误
conn.setRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)"); //得到输入流
InputStream inputStream = conn.getInputStream();
//获取自己数组
byte[] getData = readInputStream(inputStream); //文件保存位置
File saveDir = new File(savePath);
if(!saveDir.exists()){
saveDir.mkdir();
}
File file = new File(saveDir+File.separator+fileName);
FileOutputStream fos = new FileOutputStream(file);
fos.write(getData);
if(fos!=null){
fos.close();
}
if(inputStream!=null){
inputStream.close();
} System.out.println("info:"+url+" download success"); } /**
* 从输入流中获取字节数组
* @param inputStream
* @return
* @throws IOException
*/
public static byte[] readInputStream(InputStream inputStream) throws IOException {
byte[] buffer = new byte[1024];
int len = 0;
ByteArrayOutputStream bos = new ByteArrayOutputStream();
while((len = inputStream.read(buffer)) != -1) {
bos.write(buffer, 0, len);
}
bos.close();
return bos.toByteArray();
} public static void main(String[] args) {
try{
downLoadFromUrl("http://101.95.48.97:8005/res/upload/interface/apptutorials/manualstypeico/6f83ce8f-0da5-49b3-bac8-fd5fc67d2725.png",
"百度.jpg","d:/resource/images/diaodiao/country/");
}catch (Exception e) {
// TODO: handle exception
}
}