URL url = new URL("https://www.netkiller.cn");
URLConnection connection = url.openConnection();
System.out.println(connection.getContentType());
System.out.println(connection.getContentLength());
System.out.println(connection.getContentEncoding());
System.out.println(connection.getDate());
System.out.println(connection.getExpiration());
System.out.println(connection.getLastModified());		
		
		

		
URL url = new URL("https://www.netkiller.cn");
URLConnection connection = url.openConnection();

try (InputStream in = connection.getInputStream();) {

    ByteArrayOutputStream output = new ByteArrayOutputStream();
    byte[] buffer = new byte[1024];
    int len = -1;
    while ((len = in.read(buffer)) != -1) {
        output.write(buffer, 0, len);
    }

    System.out.println(new String(output.toByteArray()));

} catch (IOException e) {
    e.printStackTrace();
}