我正在尝试使用以下方法下载此文件(http://github.com/downloads/TheHolyWaffle/ChampionHelper/ChampionHelper-4.jar),但似乎无效。我收到一个空的/损坏的文件。
String link = "http://github.com/downloads/TheHolyWaffle/ChampionHelper/ChampionHelper-4.jar";
String fileName = "ChampionHelper-4.jar";
URL url = new URL(link);
URLConnection c = url.openConnection();
c.setRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; .NET CLR 1.0.3705; .NET CLR 1.1.4322; .NET CLR 1.2.30703)");
InputStream input;
input = c.getInputStream();
byte[] buffer = new byte[4096];
int n = -1;
OutputStream output = new FileOutputStream(new File(fileName));
while ((n = input.read(buffer)) != -1) {
if (n > 0) {
output.write(buffer, 0, n);
}
}
output.close();
但我可以使用相同的方法从我的保管箱(http://dl.dropbox.com/u/13226123/ChampionHelper-4.jar)成功下载以下文件。
所以不知何故,Github知道我不是一个试图下载文件的普通用户。我已经尝试更改用户代理,但这也无济于事。
那么我应该如何使用Java下载托管在我的Github帐户上的文件?
编辑:我尝试使用apache commons-io但是我得到了同样的效果,一个空/损坏的文件。答案 0 :(得分:3)
当你请求这个文件时,看起来GitHub会给你几个级别的重定向,而this StackOverflow article表明URLConnection不会自动跟随改变协议的重定向。以下是我所看到的curl:
第一次请求:
curl -v http://github.com/downloads/TheHolyWaffle/ChampionHelper/ChampionHelper-4.jar
* About to connect() to github.com port 80 (#0)
* Trying 207.97.227.239... connected
* Connected to github.com (207.97.227.239) port 80 (#0)
> GET /downloads/TheHolyWaffle/ChampionHelper/ChampionHelper-4.jar HTTP/1.1
> User-Agent: curl/7.21.4 (universal-apple-darwin11.0) libcurl/7.21.4 OpenSSL/0.9.8r zlib/1.2.5
> Host: github.com
> Accept: */*
>
< HTTP/1.1 301 Moved Permanently
< Server: nginx < Date: Sun, 18 Nov 2012 15:56:36 GMT
< Content-Type: text/html < Content-Length: 178
< Connection: close
< Location: https://github.com/downloads/TheHolyWaffle/ChampionHelper/ChampionHelper-4.jar
< <html> <head><title>301 Moved Permanently</title></head> <body bgcolor="white"> <center><h1>301 Moved Permanently</h1></center> <hr><center>nginx</center> </body> </html>
* Closing connection #0
此位置标题的卷曲:
curl -v https://github.com/downloads/TheHolyWaffle/ChampionHelper/ChampionHelper-4.jar
* About to connect() to github.com port 443 (#0)
* Trying 207.97.227.239... connected
* Connected to github.com (207.97.227.239) port 443 (#0)
* SSLv3, TLS handshake, Client hello (1):
* SSLv3, TLS handshake, Server hello (2):
* SSLv3, TLS handshake, CERT (11):
* SSLv3, TLS handshake, Server finished (14):
* SSLv3, TLS handshake, Client key exchange (16):
* SSLv3, TLS change cipher, Client hello (1):
* SSLv3, TLS handshake, Finished (20):
* SSLv3, TLS change cipher, Client hello (1):
* SSLv3, TLS handshake, Finished (20):
* SSL connection using RC4-SHA
* Server certificate:
* subject: businessCategory=Private Organization; 1.3.6.1.4.1.311.60.2.1.3=US; 1.3.6.1.4.1.311.60.2.1.2=California; serialNumber=C3268102; C=US; ST=California; L=San Francisco; O=GitHub, Inc.; CN=github.com
* start date: 2011-05-27 00:00:00 GMT
* expire date: 2013-07-29 12:00:00 GMT
* subjectAltName: github.com matched
* issuer: C=US; O=DigiCert Inc; OU=www.digicert.com; CN=DigiCert High Assurance EV CA-1
* SSL certificate verify ok.
> GET /downloads/TheHolyWaffle/ChampionHelper/ChampionHelper-4.jar HTTP/1.1
> User-Agent: curl/7.21.4 (universal-apple-darwin11.0) libcurl/7.21.4 OpenSSL/0.9.8r zlib/1.2.5
> Host: github.com
> Accept: */*
>
< HTTP/1.1 302 Found
< Server: nginx
< Date: Sun, 18 Nov 2012 15:58:56 GMT
< Content-Type: text/html; charset=utf-8
< Connection: keep-alive
< Status: 302 Found
< Strict-Transport-Security: max-age=2592000
< Cache-Control: no-cache
< X-Runtime: 48
< Location: http://cloud.github.com/downloads/TheHolyWaffle/ChampionHelper/ChampionHelper-4.jar
< X-Frame-Options: deny
< Content-Length: 149
<
* Connection #0 to host github.com left intact
* Closing connection #0
* SSLv3, TLS alert, Client hello (1):
<html><body>You are being <a href="http://cloud.github.com/downloads/TheHolyWaffle/ChampionHelper/ChampionHelper-4.jar">redirected</a>.</body></html>
此响应中的位置标头返回实际文件。您可能希望使用Apache HTTP Client下载它。您可以将其设置为在GET期间遵循这些301和302重定向。
答案 1 :(得分:2)
这个人做的工作:
public class Download {
private static boolean isRedirected( Map<String, List<String>> header ) {
for( String hv : header.get( null )) {
if( hv.contains( " 301 " )
|| hv.contains( " 302 " )) return true;
}
return false;
}
public static void main( String[] args ) throws Throwable
{
String link =
"http://github.com/downloads/TheHolyWaffle/ChampionHelper/" +
"ChampionHelper-4.jar";
String fileName = "ChampionHelper-4.jar";
URL url = new URL( link );
HttpURLConnection http = (HttpURLConnection)url.openConnection();
Map< String, List< String >> header = http.getHeaderFields();
while( isRedirected( header )) {
link = header.get( "Location" ).get( 0 );
url = new URL( link );
http = (HttpURLConnection)url.openConnection();
header = http.getHeaderFields();
}
InputStream input = http.getInputStream();
byte[] buffer = new byte[4096];
int n = -1;
OutputStream output = new FileOutputStream( new File( fileName ));
while ((n = input.read(buffer)) != -1) {
output.write( buffer, 0, n );
}
output.close();
}
}
答案 2 :(得分:1)
我找到了解决方案。
显然http://github.com/downloads/TheHolyWaffle/ChampionHelper/ChampionHelper-4.jar
没有直接链接到我的文件。
使用文本编辑器查看生成的jar时,我发现了:
<html><body>You are being <a href="http://cloud.github.com/downloads/TheHolyWaffle/ChampionHelper/ChampionHelper-4.jar">redirected</a>.</body></html>
所以这意味着直接链接如下:http://cloud.github.com/downloads/TheHolyWaffle/ChampionHelper/ChampionHelper-4.jar
通过此链接,我可以使用我的方法下载文件,没有任何问题。
答案 3 :(得分:1)
获取原始二进制文件的直接下载链接,例如
https://github.com/xerial/sqlite-jdbc/blob/master/src/main/resources/org/sqlite/native/Windows/x86_64/sqlitejdbc.dll?raw=true
通过复制View Raw
链接:
最后使用以下代码下载文件:
public static void download(String downloadURL) throws IOException
{
URL website = new URL(downloadURL);
String fileName = getFileName(downloadURL);
try (InputStream inputStream = website.openStream())
{
Files.copy(inputStream, Paths.get(fileName), StandardCopyOption.REPLACE_EXISTING);
}
}
public static String getFileName(String downloadURL)
{
String baseName = FilenameUtils.getBaseName(downloadURL);
String extension = FilenameUtils.getExtension(downloadURL);
String fileName = baseName + "." + extension;
int questionMarkIndex = fileName.indexOf("?");
if (questionMarkIndex != -1)
{
fileName = fileName.substring(0, questionMarkIndex);
}
fileName = fileName.replaceAll("-", "");
return URLDecoder.decode(fileName, "UTF-8");
}
您还需要Apache Commons IO
类的FilenameUtils
maven依赖项:
<dependency>
<groupId>commons-io</groupId>
<artifactId>commons-io</artifactId>
<version>LATEST</version>
</dependency>
答案 4 :(得分:0)