A transaction that appends new file content to the end of an existing file. The contents of the file can be viewed by submitting a FileContentsQuery request.
Transaction Signing Requirements
- The key on the file is required to sign the transaction if different than the client operator account key
Transaction Fees
- Please see the transaction and query fees table for base transaction fee
- Please use the Hedera fee estimator to estimate your transaction fee cost
| Constructor | Description |
|---|
FileAppendTransaction() | Initializes the FileAppendTransaction object |
new FileAppendTransaction()
The default max transaction fee (1 hbar) is not enough to create a file. Use setMaxTransactionFee()to change the default max transaction fee from 1 hbar to 2 hbars. The default chunk size is 2,048 bytes.
Methods
| Method | Type | Description | Requirement |
|---|
setFileId(<fileId>) | FileId | The ID of the file to append | Required |
setContents(<text>) | String | The content in String format | Optional |
setContents(<content>) | byte [ ] | The content in byte format | Optional |
setChunkSize(<chunkSize>) | int | The chunk size | Optional |
setMaxChunkSize(<maxChunks>) | int | The max chunk size | Optional |
//Create the transaction
FileAppendTransaction transaction = new FileAppendTransaction()
.setFileId(newFileId)
.setContents("The appended contents");
//Change the default max transaction fee to 2 hbars
FileCreateTransaction modifyMaxTransactionFee = transaction.setMaxTransactionFee(new Hbar(2));
//Prepare transaction for signing, sign with the key on the file, sign with the client operator key and submit to a Hedera network
TransactionResponse txResponse = modifyMaxTransactionFee.freezeWith(client).sign(key).execute(client);
//Request the receipt
TransactionReceipt receipt = txResponse.getReceipt(client);
//Get the transaction consensus status
Status transactionStatus = receipt.status;
System.out.println("The transaction consensus status is " +transactionStatus);
//v2.0.0
Get transaction values
| Method | Type | Description | Requirement |
|---|
getFileId() | FileId | The file ID in the transaction | Optional |
getContents() | String | The content in the transaction | Optional |
//Create the transaction
FileAppendTransaction transaction = new FileAppendTransaction()
.setFileId(newFileId)
.setContents("The appended contents");
//Get the contents
ByteString getContents = transaction.getContents();
//v2.0.0
