not sure what you mean by "call bytearrayinputstream" or what you want to do with one, but to create an instance of one, try:
B4X:
dim bais as javaobject
bais.initializenewinstance("java.io.ByteArrayInputStream",null)
then you might try things like these:
B4X:
dim int bytesavailable = bais.runmethod("available",null)
dim bytes() as byte = bais.runmethod("readAllbytes",null)