我已经测试了第一步（登录页面）并且它有效。我输入了所有参数（用户、密码等），然后可以打印结果（包含我的数据的页面）。问题是当我尝试从该网站下载文件时。我需要第一步的饼干。在我下载的文件中，我有消息：“会话过期”。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。