Hi Duncan
yes, that's an old and well known problem.
The good news is that we have a couple ideas and are waiting for 2.3.0 to get
out before implementing it (http://jira.codehaus.org/browse/GEOT-602)
So please keep in sync since we're going to fix it asap, and do not hesitate
to talk back if you have any suggestion.
regards,
Gabriel
On Thursday 14 September 2006 13:25, Duncan Clarkson wrote:
> Hi,
>
> We're having a problem with the way that geotools 2.1.1+ deals with
> parsing literal values in OGC filters. We are providing data to users
> via Geoserver 1.3.0 which uses the 2.1.1 version of Geotools.
>
> Some of the datasets we offer have a string column called 'label'
> although the value of this field can be numeric and can contain leading
> zeros. We need to generate EqualTo and Like filters based on these
> fields but the problem is that they are being treated as integers by
> geotools. Here is the code that handles this
> (org.geotools.filter.ExpressionSAXParser):
>
> } else if (curExprssn instanceof LiteralExpression) {
> // This is a relatively loose assignment routine, which
> uses // the fact that the three allowed literal types have a strict
> // instatiation hierarchy (ie. double can be an int can
> be a
> // string, but not the other way around).
> // A better routine would consider the use of this
> expression
> // (ie. will it be compared to a double or searched with a
> // like filter?)
> //HACK: This should also not use exception catching, it's
> //expensive and bad code practice.
> try {
> Object temp = new Integer(message);
> ((LiteralExpression) curExprssn).setLiteral(temp);
> currentState = "complete";
> } catch (NumberFormatException nfe1) {
> try {
> Object temp = new Double(message);
> ((LiteralExpression) curExprssn).setLiteral(temp);
> currentState = "complete";
> } catch (NumberFormatException nfe2) {
> Object temp = message;
> ((LiteralExpression) curExprssn).setLiteral(temp);
> currentState = "complete";
> }
> }
> }
>
> So if the literal can be converted to a number it will be, leading zeros
> will be lost. This of course means that the SQL generated by Geoserver
> to extract the features will return no data as '007' != 7.
>
> We were thinking that a better way to handle this would be not to try
> and convert a literal unless it is required by a calculation. Any ideas
> or plans for what to do about this?
>
> Duncan
>
> PS. For completeness sake here is the output I have from Geoserver:
>
> 176638862 [FINER] org.geotools.filter.ExpressionSAXParser - incoming
> type: Literal
> 176638862 [FINER] org.geotools.filter.ExpressionSAXParser - declared
> type: PropertyName
> 176638862 [FINER] org.geotools.filter.ExpressionSAXParser - current
> state: complete
> 176638863 [FINER] org.geotools.filter.ExpressionSAXParser - is literal
> expression
> 176638863 [FINER] GMLFilterDocument - RETURN
> 176638864 [FINER] GMLFilterDocument - ENTRY [EMAIL PROTECTED] 77 3
> 176638864 [FINER] org.geotools.filter.ExpressionSAXParser - incoming
> message: 007
> 176638864 [FINER] org.geotools.filter.ExpressionSAXParser - should read
> chars: true
> 176638865 [FINER] GMLFilterDocument - RETURN
> 176638865 [FINER] GMLFilterDocument - ENTRY http://www.opengis.net/ogc
> Literal ogc:Literal
> 176638865 [FINER] org.geotools.filter.FilterFilter - found start
> element: Literal
> 176638865 [FINER] AbstractFilter - ENTRY 109
> 176638865 [FINER] org.geotools.filter.FilterFilter - found an expression
> filter end
> 176638866 [FINER] org.geotools.filter.ExpressionSAXParser - declared
> type: Literal
> 176638866 [FINER] org.geotools.filter.ExpressionSAXParser - end message:
> Literal
> 176638867 [FINER] org.geotools.filter.ExpressionSAXParser - current
> state: complete
> 176638867 [FINER] org.geotools.filter.FilterFilter - expression factory
> is ready
> 176638868 [FINER] org.geotools.filter.ExpressionSAXParser - about to
> create expression: 7
> 176638868 [FINER] org.geotools.filter.FilterSAXParser - current state
> (end): complete
> 176638869 [FINER] GMLFilterDocument - RETURN
> 176638869 [FINER] GMLFilterDocument - ENTRY http://www.opengis.net/ogc
> PropertyIsEqualTo ogc:PropertyIsEqualTo
> 176638869 [FINER] org.geotools.filter.FilterFilter - found start
> element: PropertyIsEqualTo
> 176638869 [FINER] AbstractFilter - ENTRY 14
> 176638870 [FINER] org.geotools.filter.FilterSAXParser - complete called,
> state = complete
> 176638870 [FINER] org.geotools.filter.LogicSAXParser - added a filter: [
> label = 7 ]
> 176638870 [FINER] org.geotools.filter.LogicSAXParser - added to sub
> filters: [ label = 7 ]
>
> -------------------------------------------------------------------------
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--
Gabriel Roldán ([EMAIL PROTECTED])
Axios Engineering (http://www.axios.es)
Tel. +34 944 41 63 84
Fax. +34 944 41 64 90
-------------------------------------------------------------------------
Using Tomcat but need to do more? Need to support web services, security?
Get stuff done quickly with pre-integrated technology to make your job easier
Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo
http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642
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