Create byte[] in Jython

Question

I am developing with Jython and I need to use a Java method that requires a byte[] as a parameter.

I tried:

def randomBytesArray(length):
    data = []
    for _ in xrange(length):
        data.append(chr(random.getrandbits(8)))
    methodThatNeedsBytesArrays(data)

But I get this error:

TypeError: methodThatNeedsBytesArrays(): 1st arg can't be coerced to byte[]

Answer 1

Sometimes you need to pass a byte array to a function so that the function will fill the byte array with a result. In that case, sending a Python string won't work because Python strings are immutable. Instead, create a Java byte array with the jarray module:

import jarray
bytes = jarray.zeros(100, "b")
length = zlibDeflater.deflate(bytes)
...