Input of Xerces parser

in which programming language occurs this problem? (Java docs say that input stream is supported)

Assuming you mean Xerces-C, I'm assuming by char buffer you mean that you want to create a SAX parser?

I'm guessing you want to use these 2 functions:
http://www.saxproject.org/apidoc/or...ax.InputSource)
http://www.saxproject.org/apidoc/or...java.io.Reader)

You need to create a java.io.Reader encapsulating the character stream and then encapsulate that in an input source, before sending it to the XMLReader to be parsed.