java implements two ways to download files
- 2020-11-20 06:07:41
- OfStack
This article examples for you to share java implementation file download specific code, for your reference, the specific content is as follows
public HttpServletResponse download(String path, HttpServletResponse response) {
try {
// path The path of the file to be downloaded.
File file = new File(path);
// Gets the file name.
String filename = file.getName();
// Gets the suffix name of the file.
String ext = filename.substring(filename.lastIndexOf(".") + 1).toUpperCase();
// Download the file as a stream.
InputStream fis = new BufferedInputStream(new FileInputStream(path));
byte[] buffer = new byte[fis.available()];
fis.read(buffer);
fis.close();
// empty response
response.reset();
// Set up the response the 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 {
// Download local files
String fileName = "Operator.doc".toString(); // The default save name of the file
// Read to the stream
InputStream inStream = new FileInputStream("c:/Operator.doc");// File storage path
// Format the output
response.reset();
response.setContentType("bin");
response.addHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\"");
// Iterate through the data in the stream
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 {
// Download network files
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();
}
}
// Supports 1 way to open files online
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(); // It is very important
if (isOnLine) { // Online open mode
URL u = new URL("file:///" + filePath);
response.setContentType(u.openConnection().getContentType());
response.setHeader("Content-Disposition", "inline; filename=" + f.getName());
// The file name should be encoded as UTF-8
} else { // Pure download mode
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();
}