使用发布请求从页面下载文件(需要cookie)

时间:2012-10-21 22:30:00

标签: java cookies httpurlconnection

我已经测试了第一步(登录页面)并且它有效。我把所有参数(用户,传递等),我可以打印结果(页面与我的数据)。问题是当我尝试从该网络下载文件时。我需要第一步的cookie。在我下载的文件中,我收到了消息:“Expired session”。这是我的代码:

URL login = new URL("..."); 
URL download_page = new URL("..."); 
URL document_link new URL("..."); 


//String for request
String data_post = "username=name&password=1234&other_data=..."; 

//Login page
HttpURLConnection conn = (HttpURLConnection)login.openConnection(); 
conn.setDoOutput(true);
OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream()); 
wr.write(data_post); 
wr.close(); 
conn.connect(); 

//Download page
HttpURLConnection connDownload = (HttpURLConnection)download_page.openConnection(); 
connDownload.connect(); 

//Link to the file 
HttpURLConnection connFile = (HttpURLConnection)document_link.openConnection(); 
connFile.connect(); 

BufferedInputStream in = new BufferedInputStream(connFile.getInputStream()); 

File saveFile = new File("myfile.txt"); 
OutputStream out = new BufferedOutputStream(new FileOutputStream(saveFile)); 
byte[] buf = new byte[256]; 
int n = 0; 
while ((n=in.read(buf))>=0) { 
   out.write(buf, 0, n); 
} 
out.flush(); 
out.close();  

提前致谢。

1 个答案:

答案 0 :(得分:0)

在关闭连接之前,您是否尝试在第一页上检查Cookie的标头?我会尝试类似的事情:

String cookies = conn.getHeaderField("Set-Cookie");

然后在执行connect()之前,在以下连接中设置cookie,使用:

connDownload.setRequestProperty("Cookie", cookies);

......看看是否有效......