🚀 go-pugleaf

"Kent" <Kent.White@att.net> wrote:
>
>I have an application written in Delphi that I am porting to 
>Java. In the delphi program I read in some real values in 
>BigEndian format. I then convert these to Windows real format 
>by using a variant record, which Java doesn't have, to swap
>bytes so that the proper format can be obtained. 
>
>How do I accomplish the same task in Java? Below is the code
>that swaps the proper bytes to get the value in the proper 
>format.
>
>type
>  realvar = record  // Note use of variant record which Java does not have.
>              case RealNum:byte of
>                1:(bytename: byte4);
>                2:(realname: single);
>            end;
>  WordVar = record
>              case WordNum:byte of
>                1:(ByteName: Byte2);
>                2:(WordName: Word);
>            end;
>
>// procedures
>function TSDIAppForm.Convert(ByteArray:single):single;
>var
>  temp : realvar;
>begin
>  temp.realname := ByteArray;
>  swap(temp.bytename[1], temp.bytename[4]);
>  swap(temp.bytename[2], temp.bytename[3]);
> try
>  begin
>    if temp.realname < 0 then
>      Convert := 0
>    else
>      Convert := temp.realname;
>  end
> except
>   on EInvalidOp do
>     Convert := 0;
> end;
>end; { of Convert }
>
>function TSDIAppForm.ConvertWord(Value : Word):Word;
>var
>  Temp : Wordvar;
>begin
>  Temp.wordName := Value;
>  Swap(temp.ByteName[1], Temp.ByteName[2]);
>  ConvertWord := Temp.WordName;
>end; { of ConvertWord }
>

Kent wrote:
> How do I accomplish the same task in Java? Below is the code
> that swaps the proper bytes to get the value in the proper 
> format.

Read the values as 4 bytes, turn them into an int, then use 
Float.intBitsToFloat.  Something like this (uncompiled and untested, but 
if you treat it as pseudocode, it should more or less work).

     float readBigEndianFloat(InputStream in) throws IOException {
         DataInputStream dataIn = new DataInputStream(in);
         byte[] bytes = new byte[4];
         dataIn.readFully(bytes);
         int i = (byte[3] << 24) | (byte[2] << 16) | (byte[1] << 8) | 
byte[0];
         return Float.intBitsToFloat(i);
     }

-- 
Gillmer J. Derge [TeamB]