Class AtomicFileWriter

java.lang.Object

net.blockhost.commons.core.io.AtomicFileWriter

public final class AtomicFileWriter
extends Object

Utility class for writing files atomically using a write-to-temp-then-rename strategy.

This prevents partial or corrupt files if the process crashes mid-write. The sequence is:

1. Write content to a temporary file in the same directory as the target
2. Atomically move the temporary file to the target path
3. If atomic move is not supported by the filesystem, fall back to a regular move

The temporary file is always cleaned up, even if an error occurs during writing.

Usage

// Write a string
AtomicFileWriter.write(path, "key: value\n");

// Write bytes
AtomicFileWriter.write(path, serializedBytes);

// Write via an OutputStream (e.g. for YAML serializers)
AtomicFileWriter.write(path, out -> yaml.dump(data, new OutputStreamWriter(out)));

Method Summary

Modifier and Type	Method	Description
static void	write(Path path, byte[] content)	Writes the given byte array to the target path atomically.
static void	write(Path path, String content)	Writes the given string to the target path atomically using UTF-8 encoding.
static void	write(Path path, IOConsumer<OutputStream> writer)	Writes to the target path atomically using a consumer that receives an OutputStream.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

write

public static void write(Path path,
 byte[] content)
                  throws IOException

Writes the given byte array to the target path atomically.

Parameters:

path - the target file path

content - the bytes to write

Throws:

IOException - if an I/O error occurs

NullPointerException - if path or content is null

write

public static void write(Path path,
 String content)
                  throws IOException

Writes the given string to the target path atomically using UTF-8 encoding.

Parameters:

path - the target file path

content - the string to write

Throws:

IOException - if an I/O error occurs

NullPointerException - if path or content is null

write

public static void write(Path path,
 IOConsumer<OutputStream> writer)
                  throws IOException

Writes to the target path atomically using a consumer that receives an OutputStream.

This overload is useful when the caller wants to serialize directly to a stream (e.g. YAML or JSON writers) without first buffering the entire content into a byte array.

Parameters:

path - the target file path

writer - a consumer that writes content to the provided output stream

Throws:

IOException - if an I/O error occurs

NullPointerException - if path or writer is null