Changes

declare namespace math = "java:java.lang.Math";

math:cos(xs:double(0)), math:PI()

With the [[XQuery 3.0#Expanded QNames|Expanded QName]] notation of XQuery 3.0, the namespace can directly be embedded in the function call:

<syntaxhighlight lang="xquery">

Q{java:java.lang.Math}cos(xs:double(0))

The constructor of a class can be invoked by calling the virtual function {{Code|new()}}. Instance methods can then called by passing on the resulting Java object as first argument. In the following example, 256 bytes are written to the file {{Code|output.txt}}. First, a new {{Code|FileWriter}} instance is created, and its {{Code|write()}} function is called in the next step:

fw:close($file)

)

If the result of a Java call contains invalid XML characters, it will be rejected. The validity check can be disabled by setting {{Option|CHECKSTRINGS}} to false. In the example below, a file with a single {{Code|00}} byte is written, and this file will then be accessed by via Java functions:

br:close($br)

)

The option can also be specified via a pragma:

br:new(fr:new('00.bin')) ! (br:readLine(.), br:close(.))

}

=Module Imports=

),

set:size()

The execution of imported classes is more efficient than the execution of instances that have been created via {{Code|new()}}. In turn, no arguments can be supplied in the import statement, and the construction will only be successful if the class can be instantiated without arguments.

element error { $err:description }

}

The imported Java class is shown below:

}

}

The result will look as follows:

<user>admin</admin>

<error>Integer conversion failed: abc</error>

Please visit the XQuery 3.0 specification if you want to get more insight into

// ...

}

An XQuery expression will be handled as an [[XQuery Update#Updating Expressions|updating expression]] if it calls an updating Java function. In contrast to XQuery update operations, the Java code will immediately be executed, but the result will be cached as if {{Function|Update|update:output}} was called.

// ...

}

If an XQuery expression invokes {{Code|write()}}, any other query that calls {{Code|write()}} or {{Code|read()}} needs to wait for the query to be finished. The {{Code|read()}} function can be run in parallel; whereas queries will be queued if {{Code|write()}} is called.

Q{String}codePointAt('ABC', xs:byte(1)),

Q{String}codePointAt('ABC', 1)

===Conversion to XQuery===

let $scanner := Scanner:new("A B C") => Scanner:useDelimiter(" ")

return $scanner()

If no conversion is defined, a string is returned, resulting from the {{Code|toString()}} method of the object. This method is also called if the string representation of a Java item is requested:

'Map: ' || Q{java.util.HashMap}new(),

string(Q{java:java.util.ArrayList}new())

The conversion can be further controlled with the {{Option|WRAPJAVA}} option. The following values exist:

=> Q{java.nio.CharBuffer}wrap()

}

The next example demonstrates a use case for the {{Code|instance}} option:

}

return $set()

The {{Code|void}} option is helpful if side-effecting methods return values that do not contribute to the final result:

$set()

)

The irrelevant results could also be swallowed with {{Function|Profiling|prof:void}}.