Hi Chistian,

I am trying to use a very Big Integer in BaseX (9.1.2)

With this value :

declare namespace BigInteger = "java:java.math.BigInteger";

BigInteger:new("12345678901234567890”)

I received : Cannot convert xs:string to xs:integer: "12345678901234567890”.

The java method that I used returns a BigInteger, but I just need the value as a String.

If you have the BigInteger returned from your Java method and want it as an XQuery string try

  let $s as xs:string := BigInteger:toString($valueFromJavaMethod)

or

   let $s as xs:string := $valueFromJavaMethod => BigInteger:toString()

e.g. a complete example that works for me with BaseX 9 is

declare namespace BigInteger = "java:java.math.BigInteger";

let $s as xs:string := BigInteger:TEN() => BigInteger:toString()
return $s

Not sure about that problem with the constructor, with Saxon

declare namespace BigInteger = "java:java.math.BigInteger";

let $s as xs:string := BigInteger:new("12345678901234567890") => BigInteger:toString()
return $s

runs fine as well but with BaseX I get the error you mentioned.