Difference between revisions of "Java Bindings"
| Line 1: | Line 1: | ||
| − | The Java Binding feature is an extensibility mechanism which allows direct calling | + | The Java Binding [[Querying|query]] feature is an extensibility mechanism which allows |
| − | of Java methods bound as XQuery functions and manipulation of wrapped Java objects. | + | direct calling of Java methods bound as XQuery functions and manipulation of wrapped |
| − | The following examples introduce the behavior. Please note that the namespace URI | + | Java objects. The following examples introduce the behavior. Please note that the |
| − | must be of the form <code>java:fullyQualifiedClassName</code>. | + | namespace URI must be of the form <code>java:fullyQualifiedClassName</code>. |
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: | ||
Revision as of 19:17, 21 January 2011
The Java Binding query 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))
Note: To call a method directly it has to be set as static in you java code.
The next example writes 256 bytes to the file output.txt.
To call the write method of the FileWriter class,
you have to pass a class instance as first argument:
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)
)
Note that we recommend to use XQuery expressions and functions whenever possible, as Java code cannot be pre-compiled by BaseX, and will most probably be evaluated slower than pure XQuery code.
