hnasrullakhan opened a new issue, #46:
URL: https://github.com/apache/arrow-java/issues/46
### Describe the usage question you have. Please include as many useful
details as possible.
Hi community,
I have a trying to modify data buffers of string column.
if i print the buffer readable bytes after ` buffers.set(index,
compressedBuf); `, i see the right value.
```
List<ArrowBuf> buffers = fieldVector.getFieldBuffers();
int index = buffers.size() - 1;
ArrowBuf compressedBuf = null;
ArrowBuf originalBuf = buffers.get(index);
ByteBuffer originalBuffer = originalBuf.nioBuffer(0,
(int) originalBuf.readableBytes());
// Compress the buffer using LZ4
byte[] originalBytes = new
byte[originalBuffer.remaining()];
System.out.println("This is buffer id: "+ index + "
originalbytes: "+ originalBuf.readableBytes());
originalBuffer.get(originalBytes);
int maxCompressedLength =
compressor.maxCompressedLength(originalBytes.length);
byte[] compressedBytes = new byte[maxCompressedLength];
int compressedLength =
compressor.compress(originalBytes, 0, originalBytes.length, compressedBytes, 0,
maxCompressedLength);
// Allocate a new ArrowBuf for the compressed data
compressedBuf = allocator.buffer(compressedLength);
compressedBuf.writeBytes(compressedBytes, 0,
compressedLength);
compressedBuf.writerIndex(compressedLength);
System.out.println("This is buffer id: "+ index+ "
compressedbytes: "+ compressedBuf.readableBytes());
buffers.set(index, compressedBuf); // Replace with
compressed buffer
```
When i update my fieldvector.
```
int nullCount = fieldVector.getNullCount(); // Get the null count
ArrowFieldNode fieldNode = new
ArrowFieldNode(fieldVectorValueCount, nullCount);
ArrowBuf validityBuffer =
fieldVector.getValidityBuffer(); // Assuming it exists
ArrowBuf offsetBuffer = fieldVector.getOffsetBuffer();
// Assuming it exists
// Update FieldVector with the new compressed buffers
fieldVector.clear(); // Clear existing buffers (to
prevent memory leaks)
fieldVector.loadFieldBuffers(fieldNode,java.util.Arrays.asList(validityBuffer,
offsetBuffer, compressedBuf)); // Load the new (compressed) buffers
fieldVector.setValueCount(fieldVectorValueCount); //
Reset value count after buffer replacement
Field field1 = fieldVector.getField();
```
and i check the buffers again then buffers reflect old value.
please advise .
### Component(s)
Java
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