Re: BlobInputStream.java patch

Peter, can you comment on this?


> The current implementation of BlobInputStream does
> not properly handle 8-bit unsigned data as it blindly
> casts the byte to an int, which java most helpfully
> promotes to a signed type.  This causes problems when
> you can only return -1 to indicated EOF.
>
> The following patch fixes the bug and has been tested
> locally on image data.
>
> Chad David
> Guild Software Inc.
> davidc@guild.ab.ca
>
>
> *** BlobInputStream.java    Thu Feb 22 11:11:23 2001
> --- BlobInputStream.patched Thu Feb 22 11:10:38 2001
> ***************
> *** 58,73 ****
>      */
>     public int read() throws java.io.IOException {
>       try {
> !       if(buffer==null || bpos>=buffer.length) {
>           buffer=lo.read(bsize);
>           bpos=0;
>         }
>
>         // Handle EOF
> !       if(bpos>=buffer.length)
>           return -1;
>
> !       return (int) buffer[bpos++];
>       } catch(SQLException se) {
>         throw new IOException(se.toString());
>       }
> --- 58,81 ----
>      */
>     public int read() throws java.io.IOException {
>       try {
> !       if (buffer == null || bpos >= buffer.length) {
>           buffer=lo.read(bsize);
>           bpos=0;
>         }
>
>         // Handle EOF
> !       if(bpos >= buffer.length) {
>           return -1;
> +       }
>
> !       int ret = (buffer[bpos] & 0x7F);
> !       if ((buffer[bpos] &0x80) == 0x80) {
> !         ret |= 0x80;
> !       }
> !
> !       bpos++;
> !
> !       return ret;
>       } catch(SQLException se) {
>         throw new IOException(se.toString());
>       }
> ***************
> *** 153,156 ****
>     return true;
>       }
>
> ! }
> --- 161,164 ----
>     return true;
>       }
>
> ! }
>
>
>


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