❶ java response.getOutputStream()實現多個文件下載,已經拿到兩個位元組數組的list,下載的時候如何同時下載
可以一個介面傳多個文件,每個文件中間用特定符號拆分,也可以寫一個介面前端多次調用,將請求頭的文件格式改為blob,前端獲取文件流後調用下載
❷ Java用輸出流下載文件的時候如何直接彈出(打開)保存對話框
你好,請看下這段程序
<%
response.setCharacterEncoding("gb2312");
request.setCharacterEncoding("gb2312");
if (request.getParameter("file") != null) {
OutputStream os = null;
FileInputStream fis = null;
try {
String file = request.getParameter("file");
if (!(new File(file)).exists()) {
System.out.println("沒有文件");
return;
}
System.out.println("文件名為:"+file);
os = response.getOutputStream();
response.setHeader("content-disposition", "attachment;filename=" + file);
response.setContentType("application/vnd.rn-realmedia-vbr");//此項內容隨文件類型而異
byte temp[] = new byte[1000];
fis = new FileInputStream(file);
int n = 0;
while ((n = fis.read(temp)) != -1) {
os.write(temp, 0, n);
}
} catch (Exception e) {
out.print("出錯");
} finally {
if (os != null)
os.close();
if (fis != null)
fis.close();
}
out.clear();
out = pageContext.pushBody();
}
%>
<form action="" method="post">
<select name="file">
<option value="C:\\Downloads\\冷山\\冷山.rmvb">
冷山
</option>
</select>
<input type="submit">
</form>
❸ Java下載問題,怎樣讓IE下載該文件,而不是打開該文件
//·設置響應消息頭,告訴瀏覽器當前響應是一個下載文件
response.setContentType( "application/x-msdownload");
//考慮到文件名中可能包含非ASCII碼字元,所以應該進行編碼後再傳輸
fileName = URLEncoder. encode(fileName, "UTF-8");
//告訴瀏覽器,當前響應數據要求用戶干預保存到文件中,以及文件名是什麼
response.setHeader( "Content-Disposition", "attachment;filename=" +fileName);
❹ Java 下載文件的方法怎麼寫
參考下面
public HttpServletResponse download(String path, HttpServletResponse response) {
try {
// path是指欲下載的文件的路徑。
File file = new File(path);
// 取得文件名。
String filename = file.getName();
// 取得文件的後綴名。
String ext = filename.substring(filename.lastIndexOf(".") + 1).toUpperCase();
// 以流的形式下載文件。
InputStream fis = new BufferedInputStream(new FileInputStream(path));
byte[] buffer = new byte[fis.available()];
fis.read(buffer);
fis.close();
// 清空response
response.reset();
// 設置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;
}
// 下載本地文件
public void downloadLocal(HttpServletResponse response) throws FileNotFoundException {
String fileName = "Operator.doc".toString(); // 文件的默認保存名
// 讀到流中
InputStream inStream = new FileInputStream("c:/Operator.doc");// 文件的存放路徑
// 設置輸出的格式
response.reset();
response.setContentType("bin");
response.addHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\"");
// 循環取出流中的數據
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();
}
}
// 下載網路文件
public void downloadNet(HttpServletResponse response) throws MalformedURLException {
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();
}
}
//支持在線打開文件的一種方式
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) { // 在線打開方式
URL u = new URL("file:///" + filePath);
response.setContentType(u.openConnection().getContentType());
response.setHeader("Content-Disposition", "inline; filename=" + f.getName());
// 文件名應該編碼成UTF-8
} else { // 純下載方式
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();
}