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null pointer? Where/why?

I am trying out an html document reader, but am getting a null pointer exception for every page I try.  I don't know why, where or how I am getting it.  the following is my code.

public void readPage(String page) {
        JEditorPane jep = new JEditorPane();
        System.out.println("Created a pane");
        jep.setEditable(false);
        System.out.println("set editable to false");
        EditorKit htmlKit = jep.getEditorKitForContentType("text/html");
        System.out.println("created editor kit with " +htmlKit.toString());
        HTMLDocument doc = (HTMLDocument) htmlKit.createDefaultDocument();
        System.out.println("created document with "+ doc.toString());
        jep.setEditorKit(htmlKit);
        System.out.println("set the editor kit");
        try {
            URL u = new URL(page);
            System.out.println("created url with "+u.toString());
            InputStream in = u.openStream();
            System.out.println("opened the stream with "+in.toString());
            jep.read(in, doc);
            System.out.println("read the steam");
        }
        catch (IOException e) {
            System.err.println("something bad happened " +e);
        }
        JScrollPane scrollPane = new JScrollPane(jep);
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
        f.getContentPane().add(scrollPane);
        f.setSize(512, 342);
        f.show();
       
    }
0
tigress298
Asked:
tigress298
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1 Solution
 
CEHJCommented:
What are you passing in as 'page'? It should be a url, e.g. "file:something.html"
0
 
tigress298Author Commented:
String initialPage = "http://metalab.unc.edu/javafaq/";
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CEHJCommented:
Can you change this

>>

        catch (IOException e) {
            System.err.println("something bad happened " +e);
        }

>>

to


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


?
0
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tigress298Author Commented:
Created a pane
set editable to false
created editor kit with javax.swing.text.html.HTMLEditorKit@1ebd75b
created document with javax.swing.text.html.HTMLDocument@198cb3d
set the editor kit
created url with http://metalab.unc.edu/javafaq/
opened the stream with sun.net.www.protocol.http.HttpURLConnection$HttpInputStream@1576e70
java.lang.NullPointerException
        at javax.swing.JEditorPane.read(JEditorPane.java:516)
        at javax.swing.JEditorPane.read(JEditorPane.java:478)
        at Tests.PageDisplay.readPage(PageDisplay.java:56)
        at Tests.PageDisplay.main(PageDisplay.java:37)
Exception in thread "main" 

is the error I get either way
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CEHJCommented:
Instead of

>>jep.read(in, doc);

try

htmlKit.read(in, doc);
0
 
tigress298Author Commented:
Created a pane
set editable to false
created editor kit with javax.swing.text.html.HTMLEditorKit@110fe28
created document with javax.swing.text.html.HTMLDocument@2bc3f5
set the editor kit
created url with http://metalab.unc.edu/javafaq/
opened the stream with sun.net.www.protocol.http.HttpURLConnection$HttpInputStream@d3db51
javax.swing.text.ChangedCharSetException
        at javax.swing.text.html.parser.DocumentParser.handleEmptyTag(DocumentParser.java:169)
        at javax.swing.text.html.parser.Parser.startTag(Parser.java:372)
        at javax.swing.text.html.parser.Parser.parseTag(Parser.java:1846)
        at javax.swing.text.html.parser.Parser.parseContent(Parser.java:1881)
        at javax.swing.text.html.parser.Parser.parse(Parser.java:2047)
        at javax.swing.text.html.parser.DocumentParser.parse(DocumentParser.java:106)
        at javax.swing.text.html.parser.ParserDelegator.parse(ParserDelegator.java:78)
        at javax.swing.text.html.HTMLEditorKit.read(HTMLEditorKit.java:230)
        at javax.swing.text.DefaultEditorKit.read(DefaultEditorKit.java:132)
        at Tests.PageDisplay.readPage(PageDisplay.java:57)
        at Tests.PageDisplay.main(PageDisplay.java:37)

is now the error
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CEHJCommented:
Yep. That fixed the first one. The second one (and if my memory doesn't fail me, in one of your previous questions i mentioned that Java's html parsing libraries are flaky) is due to the parser having fallen over on parsing the file. In my experience it usually does unless things that are not pretty simple and well-formed
0
 
tigress298Author Commented:
Thanks
0
 
CEHJCommented:
8-)
0

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