Nick Georgides

Hello,

I am running a jetspeed portal which contains various portlet applications and have come across an issue after a recent reinstall where some of the portlets will return

Cannot pass a null PortletDefinition to a PortletEntity

Any idea what is causing this issue? I investigated a bit and it seems that jetspeed runs a process when new portlets are added where it creates mappings in its DB (derby in my case). If this does not complete it seems to cause this problem. Is my assumption correct? If yes, how can I restart this process?

Many thanks

Hi Henry, thanks for your reply.

I don't seem to grasp the concept of recursion Any help is much appreciated.

So, I moved the for-loop in another method and created the following:

..... for (int i=0; i<validCharacters.length; i++){ String result = null; result=validCharacters[i]+""; String temp1 = result; System.out.println(result); test(validCharacters, temp1); } } public void test(char[] validCharacters, String temp){ for (int i=0; i<validCharacters.length; i++){ String result=temp+validCharacters[i]; System.out.println(result); test(validCharacters, temp); } }

which I guess is really stupid judging from its output.

~Nick

Hi,

I'm trying to program an algorithm that returns all the combinations & permutations that can be made out of a given string.

e.g. for a "abc" it must return:
a b c aa ab ac ba bb bc ca cb cc aaa aab aac aba abb abc aca acb acc ... ... ... etc.

So far I've come up with:
String string1 = "abc"; char[] validCharacters = string1.toCharArray(); for (int i=0; i<validCharacters.length; i++){ String result = null; result=validCharacters[i]+""; String temp1 = result; System.out.println(result); for (int ii=0; ii<validCharacters.length; ii++){ result=temp1+validCharacters[ii]; String temp2=result; System.out.println(result); for (int iii=0; iii<validCharacters.length; iii++){ result=temp2+validCharacters[iii]; System.out.println(result); } } }

But that only works in the case of "abc". Any advice on how I could make this more dynamic?

~Nick

Hello ranchers,

I am developing an application/web service for RSS feed generation from HTML pages listing news stories. At this stage, I am looking into HTML scraping for extracting the necessary information.

With the help of an online example I can get the links in an HTML document using javax.swing.text.html.

public static void main(String[] args) { List links = new ArrayList(); try { // create the Reader for the HTML content URL url = new URI("http://www.slashdot.org").toURL(); URLConnection connection = url.openConnection(); Reader reader = new InputStreamReader(connection.getInputStream()); // create the HTMLDocument that will store the HTML content EditorKit editorkit = new HTMLEditorKit(); HTMLDocument document = (HTMLDocument)editorkit.createDefaultDocument(); // IgnoreCharsetDirective to avoid a ChangedCharSetException // <a href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4233012" target="_blank" rel="nofollow">http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4233012</a> document.putProperty("IgnoreCharsetDirective", new Boolean(true)); // parse HTML editorkit.read(reader, document, 0); // display the HTMLDocument in the console document.dump(System.out); // iterate through all A elements in the HTMLDocument HTMLDocument.Iterator it = document.getIterator(HTML.Tag.A); while (it.isValid()){ SimpleAttributeSet sas = (SimpleAttributeSet)it.getAttributes(); // get the HREF attribute of the A element String link = (String)sas.getAttribute(HTML.Attribute.HREF); if (link != null){ //add link to the list of links links.add(link); } it.next(); } } catch (MalformedURLException e) { e.printStackTrace(); } catch (URISyntaxException e) { e.printStackTrace(); } catch(ChangedCharSetException ccse) { System.out.println("Couldn't set correct encoding: " + ccse.getCharSetSpec()); } catch (IOException e) { e.printStackTrace(); } catch (BadLocationException e) { e.printStackTrace(); } System.out.println(links.toString()); }

For the purposes of this post I used http://www.slashdot.org as a reference news page. Now, looking at the console output of document.dump(System.out) I am getting quite confused when it comes to extracting the news title, content, author, etc. I understand that I am looking for a way to get the [beginning, end] values for each news title, story, author. I tried iterating through to DIV tags and their CLASS attributes but I didn't get anywhere. It rather felt like walking in the dark.

Any examples/documentation on how to use the parser to step into the content in such a way would be much appreciated.

NOTE: As I am only just beginning this I'm open to suggestions on using other HTML parsers if they are easier to manipulate.

Thanks in advance.