在頁(yè)面上我們一般用超鏈接執(zhí)行文件下載，如果是菜單方式，可以使用：
window.location =url 或
window.open(url,'_self')方式來(lái)調(diào)用，注意不能用ajax方式來(lái)調(diào)用，因?yàn)锳jax不能進(jìn)行文件流的傳輸，無(wú)論哪個(gè)框架還是自己寫都一樣。
下面是文件下載的java后臺(tái)的幾種實(shí)現(xiàn)方式
參考自：http://www.cnblogs.com/ungshow/archive/2009/01/12/1374491.html
1.一般下載
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();
// 取得文件的后綴名。
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(shè)置response的Header
response.addHeader("Content-Disposition", "attachment;filename=" + new String(filename.getBytes()));
//如果是中文文件名可以用下面方式設(shè)置
response.addHeader("Content-Disposition",
"attachment;filename=" + new String("中文名".getBytes(),"iso8859-1")
+ ".dat");
response.addHeader("Content-Length", "" + file.length());
OutputStream toClient = new BufferedOutputStream(response.getOutputStream());
response.setContentType("application/octet-stream");
//response.setContentType("application/excel");excel文件下載
toClient.write(buffer);
toClient.flush();
toClient.close();
//xml文件下載
/*OutputStream out = response.getOutputStream();
//OutputStream out = new BufferedOutputStream(response.getOutputStream());
response.setContentType("text/xml");
OutputFormat format = OutputFormat.createPrettyPrint();
format.setEncoding("UTF-8");
XMLWriter writer = new XMLWriter(out, format);
writer.write(doc);
writer.close();
out.close();*/
}
catch (IOException ex) {
ex.printStackTrace();
}
return null;
2. 下載本地文件
String fileName = "Operator.doc".toString(); // 文件的默認(rèn)保存名
// 讀到流中
InputStream inStream = new FileInputStream("c:/Operator.doc");// 文件的存放路徑
// 設(shè)置輸出的格式
response.reset();
response.setContentType("bin");
response.addHeader("Content-Disposition", "attachment; filename=""" + fileName + """");
// 循環(huán)取出流中的數(shù)據(jù)
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();
}
3.下載網(wǎng)絡(luò)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();
}
4.支持在線打開文件的一種方式
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(yīng)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();