JAVA download getContentLength () has been for some ideas of-1, getcontentlength-1

JAVA download getContentLength () has been for some ideas of-1, getcontentlength-1

If Content Length is not described in the header file

No solution yet

If Content Long is described in the header file

 

Solution 1:

Disguise as a browser

 conn.setRequestProperty("User-Agent", " Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36");  

Add a proxy to the code

String host = "127.0.0.1";         String port = "8888";         setProxy(host, port);        public static void setProxy(String host, String port) {        System.setProperty("proxySet", "true");        System.setProperty("proxyHost", host);        System.setProperty("proxyPort", port);    }   

 

 

Solution 2:

Add the following attributes so that the server does not require gzip compression:

Java Doc has a description of this:

By default, this implementationHttpURLConnectionRequests that servers use gzip compression. SincegetContentLength()Returns the number of bytes transmitted, you cannot use that method to predict how many bytes can be read fromgetInputStream(). Instead, read that stream until it is exhausted: whenread()Returns-1.

conn.setRequestProperty("Accept-Encoding", "identity");