diff options
Diffstat (limited to 'libjava/java')
| -rw-r--r-- | libjava/java/io/RandomAccessFile.java | 28 |
1 files changed, 21 insertions, 7 deletions
diff --git a/libjava/java/io/RandomAccessFile.java b/libjava/java/io/RandomAccessFile.java index c20549c..7907d46 100644 --- a/libjava/java/io/RandomAccessFile.java +++ b/libjava/java/io/RandomAccessFile.java @@ -194,12 +194,14 @@ public class RandomAccessFile implements DataOutput, DataInput } /** - * This method sets the length of the file to the specified length. If - * the currently length of the file is longer than the specified length, - * then the file is truncated to the specified length. If the current - * length of the file is shorter than the specified length, the file - * is extended with bytes of an undefined value. - * <p> + * This method sets the length of the file to the specified length. + * If the currently length of the file is longer than the specified + * length, then the file is truncated to the specified length (the + * file position is set to the end of file in this case). If the + * current length of the file is shorter than the specified length, + * the file is extended with bytes of an undefined value (the file + * position is unchanged in this case). + * <p> * The file must be open for write access for this operation to succeed. * * @param newlen The new length of the file @@ -208,7 +210,19 @@ public class RandomAccessFile implements DataOutput, DataInput */ public void setLength (long newLen) throws IOException { - ch.truncate (newLen); + // FIXME: Extending a file should probably be done by one method call. + + // FileChannel.truncate() can only shrink a file. + // To expand it we need to seek forward and write at least one byte. + if (newLen < length()) + ch.truncate (newLen); + else if (newLen > length()) + { + long pos = getFilePointer(); + seek(newLen - 1); + write(0); + seek(pos); + } } /** |