将actionscript float转换为java

Question

I need to convert this actionscript code to java:

p = 0xe8af7c;    
var ba: ByteArray = new ByteArray();
ba.writeFloat ((p >> 16 & 0xFF) / 255);
ba.writeFloat ((p >> 8 & 0xFF) / 255);
ba.writeFloat ((p & 0xFF) / 255);

This is what I have come up with:

int p = 0xe8af7c;
DataOutputStream dos = new DataOutputStream(new FileOutputStream(output));
dos.writeFloat ((p >> 16 & 0xFF) / 255f);
dos.writeFloat ((pix >> 8 & 0xFF) / 255f);
dos.writeFloat ((pix & 0xFF) / 255f);

But this does not produce the same results. It should produce 3f 68 e8 e9 3f 2f af b0 3e f8 f8 f9 , but it returns 3f 68 d7 98 d7 99 3f 2f c2 af c2 b0 3e d7 a8 d7 a8 d7 a9 . Does it mean actionscript handles floats different than java and this function cannot be converted like this? How should I convert this code?

EDIT: The purpose of this is to get the three digit pairs of p - e8, af, and 7c, convert them to integers, which are 232, 175, 124, then divide those values by 255, and write to DataOutputStream them.

Answer 1

Using this code

import org.apache.commons.codec.binary.Hex;

public static void main(String[] args) throws Exception {
    int p = 0xe8af7c;
    ByteArrayOutputStream bos = new ByteArrayOutputStream(12);
    DataOutputStream dos = new DataOutputStream(bos);
    dos.writeFloat((p >> 16 & 0xFF) / 255f);
    dos.writeFloat((p >> 8 & 0xFF) / 255f);
    dos.writeFloat((p & 0xFF) / 255f);
    System.out.println(Hex.encodeHexString(bos.toByteArray()));
}

I get the following output:

3f68e8e93f2fafb03ef8f8f9

which matches your desired result

3f 68 e8 e9 3f 2f af b0 3e f8 f8 f9

So you're probably writing something extra to your output that you aren't showing us here.

Also take a look at ByteBuffer for an fancy byte array with conversion methods.

Answer 2

You are writing data correctly into DataOutputStream , but it gets damaged when you pipe it into output because the data has to go to console, and your bytes are interpreted as ANSI chars and get "corrected" into UTF-8 charset, resulting in two bytes being sent to the console, which you in turn capture via OS pipeline into a file. To fix, use a FileOutputStream with a normal file as destination instead of output .