Java Notes
Read page from Web server
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// Original: Adapted from the 1997 Java Tutorial by Fred Swartz // to use Scanner classes. April 2007 // Description: Demo reading web page text lines by printing them. import java.net.*; import java.io.*; import java.util.Scanner; class ReadURL2 { public static void main(String[] notUsed) { try { URL yahooURL = new URL("http://www.yahoo.com/"); Scanner in = new Scanner(yahooURL.openStream()); while (in.hasNextLine()) { String line = in.nextLine(); System.out.println(line); // Just print it. } in.close(); } catch (MalformedURLException me) { System.err.println(me); } catch (IOException ioe) { System.err.println(ioe); } } } |
Another way to read from a server
It's possible to have more control over the connection by using the URLConnection, or HttpURLConnection classes. For example, using a URLConnection object is very similar to the above example.
URL yahooURL = new URL("http://www.yahoo.com/"); URLConnection yahooConnection = yahooURL.openConnection(); Scanner in = new Scanner(yahooConnection.openStream());
Lower-level network I/O
Java network I/O is at the level to UPD, TCP, and higher-level protocols (HTTP, SMTP, ...). It is not possible to do network I/O at the very low levels (eg, ICMP), but this is not a problem for any normal programs. However, there are a few programs (like ping and traceroute) that you can not write in Java.
References
- Socket Programming in Java by A.P.Rajshekhar