Difference between revisions of "Java Bindings"
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This example uses the java <code>Math</code> class and returns the cosine of an angle: | This example uses the java <code>Math</code> class and returns the cosine of an angle: | ||
− | <pre>declare namespace math = "java:java.lang.Math"; | + | <pre class="brush:xquery">declare namespace math = "java:java.lang.Math"; |
math:cos(xs:double(0)) | math:cos(xs:double(0)) | ||
</pre> | </pre> |
Revision as of 13:41, 13 December 2010
The Java Binding feature is an extensibility mechanism which allows direct calling
of Java methods bound as XQuery functions and manipulation of wrapped Java objects.
The following examples introduce the behavior. Please note that the namespace URI
must be of the form java:fullyQualifiedClassName
.
This example uses the java Math
class and returns the cosine of an angle:
declare namespace math = "java:java.lang.Math"; math:cos(xs:double(0))
The next example writes 256 bytes to the file output.txt
:
declare namespace fw = "java:java.io.FileWriter"; let $file := fw:new('output.txt') return ( for $i in 0 to 255 return fw:write($file, xs:int($i)), fw:close($file) )
Try/Catch
The well-known try/catch construct can be used in BaseX to intercept run-time errors. This feature will also be part of the new XQuery 1.1 Recommendation.
Example:
try { 1 + '2' } catch *($code, $desc) { concat('Error [', $code, ']: ', $desc) }
Result: Error [XPTY0004]: '+' operator: number expected, string found.