import java.net.*;
import java.io.*;
/** Simplest possible download of URL to get properties and contents.
* Based on:
* http://java.sun.com/docs/books/tutorial/networking/urls/readingURL.html
* http://java.sun.com/docs/books/tutorial/networking/urls/readingWriting.html
* http://java.sun.com/j2se/1.4/docs/api/java/net/URL.html
*
* @author Bob Futrelle, Northeastern Univ.
* @version 0.1 of 22 Feb. 2003
*/
public class SimpleURLDownload {
URL url, url2;
URLConnection conn;
String inputLine;
BufferedReader in, in2;
int i;
public static void main(String[] args) {
SimpleURLDownload loader = new SimpleURLDownload();
loader.setup();
loader.tinyRun();
loader.seeComponents();
}
void setup() {
try{
url = new URL("http://www.oreilly.com"); // absolute URL
url2 = new URL(url, "catalog/javanut4/"); // relative URL
}
catch(MalformedURLException e) { /* Ignore it */ }
} // setup()
/** Read the content from a URL input stream and print first 5 lines.
*/
void tinyRun() {
try{
in = new BufferedReader(
new InputStreamReader(
url.openStream()));
in2 = new BufferedReader(
new InputStreamReader(
url2.openStream()));
}
catch(IOException e) {System.out.println("Can't open URL " + e);}
System.out.println("\nFirst five lines of download using URL.openStream():\n");
i = 0;
try{
while ((inputLine = in.readLine()) != null && i < 5)
{System.out.println(inputLine);
i++;
}
in.close();
in2.close();
}
catch(IOException e) {System.out.println("readLine() problem " + e);}
// The above worked with no problems 2/22/03.
} // tinyRun()
/** Read the content from a URL with URL.openConnection and show some properties.
*/
void seeComponents() {
try{
url = new URL("http://www.oreilly.com"); // absolute URL
conn = url.openConnection();
// Now print some info
System.out.println("\nUsing URL.openConnection() can retrieve:\n");
System.out.println("getContentType() returns: " +
conn.getContentType());
System.out.println("getContentEncoding() returns: " +
conn.getContentEncoding());
System.out.println("getContentLength() returns: " +
conn.getContentLength());
// now, get input stream from the connection
BufferedReader in = new BufferedReader(
new InputStreamReader(
conn.getInputStream() ));
System.out.println("\nFirst five lines using URLConnection.getInputStream():\n");
i = 0;
while ((inputLine = in.readLine()) != null && i < 5)
{System.out.println(inputLine);
i++;}
}
catch(Exception e) {System.out.println("Problems w. connection/info " + e);}
} // seeComponents()
} // class SimpleURLDownload
/* Results of the above, to standard out are:
First five lines of download using URL.openStream():
www.oreilly.com -- Welcome to O'Reilly & Associates -- computer books, software conferences, online publishing
www.oreilly.com -- Welcome to O'Reilly & Associates -- computer books, software conferences, online publishing