parse HTML

VitaminB · Apr 25, 2006

Hello,

I want to parse a HTML document to get all URLs of the frames in a
frameset. I get a "NullPointer Exception" in the System.out.println...

Thanks a lot for you help.

Regards,
Marcus

##################
Java Code:
##################

URL urlobj = new URL(str);

HttpURLConnection uc = null;
uc = (HttpURLConnection)urlobj.openConnection();
uc.setUseCaches(false);
DataInputStream is = new DataInputStream(uc.getInputStream());

HTMLEditorKit hKit = new HTMLEditorKit();
HTMLDocument hDoc = new HTMLDocument();
hKit.read(is, hDoc, 0);
HTMLDocument.Iterator it = hDoc.getIterator(HTML.Tag.FRAME);

AttributeSet attSet = it.getAttributes();
String s = (String)attSet.getAttribute(HTML.Attribute.SRC);
System.out.println(s);

##################
Beispiel HTML-Seite:
##################

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Frameset//EN">
<html>
<head>

<script language="JavaScript" type="text/javascript">

</script>
</head>

<frameset cols="45%,55%">

<frame
src="/Test/HET/PerformanceTestDB.nsf/ContentDeliveryMeasurement?OpenForm">

<frameset rows="1*,1*">

<frame src="/Test/HET/PerformanceTestDB.nsf/DocsInserted?OpenView">

<frame name="docPreviewFrame"
src="/Test/HET/PerformanceTestDB.nsf/select?OpenForm">
</frameset>
</frameset>
</html>

Amfur Kilnem · Apr 25, 2006

VitaminB said:
AttributeSet attSet = it.getAttributes();
String s = (String)attSet.getAttribute(HTML.Attribute.SRC);
System.out.println(s);

attSet.getAttribute must've returned null.

VitaminB · Apr 25, 2006

Oliver Wong · Apr 25, 2006

VitaminB said:
I want to parse a HTML document to get all URLs of the frames in a
frameset. I get a "NullPointer Exception" in the System.out.println... [...]

##################
Java Code:
##################

URL urlobj = new URL(str);

HttpURLConnection uc = null;
uc = (HttpURLConnection)urlobj.openConnection();
uc.setUseCaches(false);
DataInputStream is = new DataInputStream(uc.getInputStream());

HTMLEditorKit hKit = new HTMLEditorKit();
HTMLDocument hDoc = new HTMLDocument();
hKit.read(is, hDoc, 0);
HTMLDocument.Iterator it = hDoc.getIterator(HTML.Tag.FRAME);

AttributeSet attSet = it.getAttributes();
String s = (String)attSet.getAttribute(HTML.Attribute.SRC);
System.out.println(s);

I don't see how you could have gotten an NPE from the
System.out.printlnt statement. Are you sure you didn't get it from the line
above, or possibly somewhere else? See the section titled "If you get an
error message, repeat it exactly." at
http://riters.com/JINX/index.cgi/Suggestions_20for_20Asking_20Questions_20on_20Newsgroups

- Oliver

VitaminB · Apr 25, 2006

OK, now I worked on my code and get anothere exception. But I similary
don't know why.

Here is the failure:
javax.swing.text.ChangedCharSetException
at
javax.swing.text.html.parser.DocumentParser.handleEmptyTag(DocumentParser.java:198)
at javax.swing.text.html.parser.Parser.startTag(Parser.java:401)
at javax.swing.text.html.parser.Parser.parseTag(Parser.java:1875)
at javax.swing.text.html.parser.Parser.parseContent(Parser.java:1910)
at javax.swing.text.html.parser.Parser.parse(Parser.java:2076)
at
javax.swing.text.html.parser.DocumentParser.parse(DocumentParser.java:135)
at
javax.swing.text.html.parser.ParserDelegator.parse(ParserDelegator.java:107)
at javax.swing.text.html.HTMLEditorKit.read(HTMLEditorKit.java:262)
at javax.swing.text.DefaultEditorKit.read(DefaultEditorKit.java:163)
at Stress.urlRequest(Stress.java:76)
at Stress.run(Stress.java:40)

Here are the code:

public long[] urlRequest(String str) {
Cal starttime = new Cal();
long[] read = new long[2];
try {
int c = 0;
byte[] rc = new byte[1024];
URL urlobj = new URL(str);

HTTPRequest request = new HTTPRequest(str, user, pass);
DataInputStream is = new DataInputStream( request.get() );

HTMLEditorKit hKit = new HTMLEditorKit();
HTMLDocument hDoc = new HTMLDocument();
hKit.read(is, hDoc, 0);

HTMLDocument.Iterator it = hDoc.getIterator(HTML.Tag.FRAME);
it.next();
AttributeSet attSet = it.getAttributes();
String s = (String)attSet.getAttribute(HTML.Attribute.SRC);
System.out.println(s);

//System.out.println(attSet.getAttributeCount());

while (( c = is.read(rc)) != -1 ) {
read[0] = read[0] + c;
}
Cal endtime = new Cal();
read[1] = endtime.getTimeInMillis() -
starttime.getTimeInMillis();
return read;
}
catch ( Exception e ) {
e.printStackTrace();
}
return read;
}

}

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parse HTML

VitaminB

Amfur Kilnem

VitaminB

Oliver Wong

VitaminB

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