append-to-a-file.md

Append to a file

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()

{% hint style="info" %} 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. {% endhint %}

Methods

{% tabs %} {% tab title="V1" %}

Method	Type	Description	Requirement
setFileId(<fileId>)	FileId	The ID of the file to append	Required
setContents(<content>)	byte [ ]	The content in byte format	Optional
setContents(<content>)	String	The content in string format	Optional

{% code title="Java" %}

FileAppendTransaction transaction = new FileAppendTransaction()
       .setFileId(newFileId)
       .setContents("The appended contents")
       .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
TransactionId txId = transaction.build(client).sign(key).execute(client);

//Request the receipt
TransactionReceipt receipt1 = txId.getReceipt(client);

//Get the transaction consensus status
Status transactionStatus = receipt.status;

System.out.println("The transaction consensus status is " +transactionStatus)

{% endcode %}

{% code title="JavaScript" %}

const transaction = new FileAppendTransaction()
       .setFileId(newFileId)
       .setContents("The appended contents")
       .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
const txId = await transaction.build(client).sign(key).execute(client);

//Request the receipt
const receipt = await txId.getReceipt(client);

//Get the transaction consensus status
Status transactionStatus = receipt.status;

console.log("The transaction consensus status is " +transactionStatus)

{% endcode %} {% endtab %} {% endtabs %}

Get transaction values

{% tabs %} {% tab title="V2" %}

Method	Type	Description	Requirement
getFileId()	FileId	The file ID in the transaction	Optional
getContents()	String	The content in the transaction	Optional

{% code title="Java" %}

//Create the transaction
FileAppendTransaction transaction = new FileAppendTransaction()
    .setFileId(newFileId)
    .setContents("The appended contents");

//Get the contents
ByteString getContents = transaction.getContents();

//v2.0.0

{% endcode %}

{% code title="JavaScript" %}

//Create the transaction
const transaction = new FileAppendTransaction()
    .setFileId(newFileId)
    .setContents("The appended contents");

//Get the contents
const getContents = transaction.getContents();

{% endcode %}

{% code title="Go" %}

//Create the transaction
transaction2 := hedera.NewFileAppendTransaction().
    SetFileID(newFileId).
        SetContents([]byte("The appended contents"))

//Get the contents
getContents2 := transaction2.GetContents()

//v2.0.0

{% endcode %} {% endtab %} {% endtabs %}