net.openhft.chronicle.core.io

Class IOTools

java.lang.Object

net.openhft.chronicle.core.io.IOTools

public final class IOTools
extends Object

Utility methods for common IO tasks used throughout the tests and tools.

Methods are grouped by purpose:

• File operations such as directory deletion and temporary file creation.
• Resource loading utilities for locating and reading files.
• Buffer handling helpers for working with ByteBuffer instances.

Typical usage is to call deleteDirWithFilesOrThrow(File...) before a test starts to ensure any previous state has been removed.

Field Summary

Fields

Modifier and Type	Field and Description
static int	IOSTATUS_INTERRUPTED

Method Summary

Modifier and Type	Method and Description
static long	addressFor(ByteBuffer byteBuffer) Gets the memory address of the given ByteBuffer.
static void	clean(ByteBuffer bb) Calls the system's Cleaner Service to clean the given ByteBuffer.
static void	createDirectories(Path dir) Creates a directory at the specified path, including any necessary but nonexistent parent directories.
static Path	createTempDirectory(String s) Creates a temporary directory with the specified name.
static File	createTempFile(String s) Creates a temporary file in a temporary directory with the specified name.
static boolean	deleteDirWithFiles(@NotNull File dir) Attempts to delete directories and their files.
static boolean	deleteDirWithFiles(@NotNull File dir, int maxDepth) Attempts to delete directories and their files.
static boolean	deleteDirWithFiles(String... dirs) Deletes each supplied directory and its contents.
static boolean	deleteDirWithFiles(@NotNull String dir, int maxDepth) Attempts to delete the specified directory and its files recursively up to a given depth.
static void	deleteDirWithFilesOrThrow(File... dirs) Variant accepting File objects.
static void	deleteDirWithFilesOrThrow(String... dirs) Removes the supplied directories and throws if any remain.
static void	deleteDirWithFilesOrWait(long timeoutMs, @NotNull File dir) Polls until the supplied directory disappears or the timeout elapses.
static void	destroyProcess(@NotNull Process process) Best-effort cleanup of a child Process: waits up to one second for the process to exit, calls Process.destroy(), waits up to another second, and finally escalates to Process.destroyForcibly() if the child is still alive.
static boolean	isClosedException(Exception e) Tests whether an exception was thrown because a network channel was already closed.
static boolean	isDirectBuffer(ByteBuffer byteBuffer) Checks if a ByteBuffer is a direct buffer.
static int	normaliseIOStatus(int n) Normalizes an I/O operation status code.
static InputStream	open(URL url) Creates and returns a new InputStream from the provided url.
static byte[]	readAsBytes(InputStream is) Reads data from an input stream and returns it as a byte array.
static byte[]	readFile(Class<?> clazz, @NotNull String name) This method first looks for the file in the classpath.
static boolean	shallowDeleteDirWithFiles(@NotNull File dir) Attempts to delete a directory with its files.
static boolean	shallowDeleteDirWithFiles(@NotNull String directory) Attempts to delete a directory with its files.
static @NotNull String	tempName(@NotNull String filename) Creates a temporary name for a file by appending the system's current nanosecond time to the file name.
static void	unmonitor(Object t) Stops the monitoring of the specified object.
static @NotNull URL	urlFor(Class<?> clazz, String name) Ensures that directory is absent or deleted, awaits for given timeout if necessary.
static @NotNull URL	urlFor(ClassLoader classLoader, String name) Ensures that directory is absent or deleted, awaits for given timeout if necessary.
static void	writeFile(@NotNull String filename, byte[] bytes) Writes the given byte array to a file with the specified name.

Methods inherited from class java.lang.Object

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

Field Detail

IOSTATUS_INTERRUPTED

public static final int IOSTATUS_INTERRUPTED

See Also:

Constant Field Values

Method Detail

isClosedException

public static boolean isClosedException(Exception e)

Tests whether an exception was thrown because a network channel was already closed.

The check compares the message against a set of operating system specific texts. It is therefore best-efforts and may return false even when the connection is gone. It is intended only to quieten logging once the application has detected a disconnect.

Parameters:

e - candidate exception

Returns:

true if the message matches a known closed connection error

shallowDeleteDirWithFiles

public static boolean shallowDeleteDirWithFiles(@NotNull
                                                @NotNull String directory)
                                         throws IORuntimeException

Attempts to delete a directory with its files. If the directory or any subdirectories contain directories themselves, the method will stop at the first layer of directories and will not delete them.

Parameters:

directory - The directory to be deleted

Returns:

true if deletion is successful, false otherwise

Throws:

IORuntimeException - if an I/O error occurs

shallowDeleteDirWithFiles

public static boolean shallowDeleteDirWithFiles(@NotNull
                                                @NotNull File dir)
                                         throws IORuntimeException

Attempts to delete a directory with its files. If the directory or any subdirectories contain directories themselves, the method will stop at the first layer of directories and will not delete them.

Parameters:

dir - The directory to be deleted

Returns:

true if deletion is successful, false otherwise

Throws:

IORuntimeException - if an I/O error occurs

deleteDirWithFiles

public static boolean deleteDirWithFiles(@NotNull
                                         String... dirs)
                                  throws IORuntimeException

Deletes each supplied directory and its contents. This is commonly used by tests to clear previous output before recreating files.

Throws:

IORuntimeException

deleteDirWithFiles

public static boolean deleteDirWithFiles(@NotNull
                                         @NotNull String dir,
                                         int maxDepth)
                                  throws IORuntimeException

Attempts to delete the specified directory and its files recursively up to a given depth. If the depth limit is reached, an AssertionError is thrown.

Parameters:

dir - The directory to be deleted

maxDepth - The maximum depth of directories to be deleted

Returns:

true if deletion is successful, false otherwise

Throws:

IORuntimeException - if an I/O error occurs

deleteDirWithFiles

public static boolean deleteDirWithFiles(@NotNull
                                         @NotNull File dir)
                                  throws IORuntimeException

Attempts to delete directories and their files. If any directory is not deleted successfully, throws an AssertionError.

Parameters:

dir - The directories to be deleted

Throws:

IORuntimeException - if an I/O error occurs

deleteDirWithFiles

public static boolean deleteDirWithFiles(@NotNull
                                         @NotNull File dir,
                                         int maxDepth)
                                  throws IORuntimeException

Attempts to delete directories and their files. If any directory is not deleted successfully, throws an AssertionError.

Parameters:

dir - The directories to be deleted

maxDepth - The maximum depth of directories to be deleted

Throws:

IORuntimeException - if an I/O error occurs

deleteDirWithFilesOrThrow

public static void deleteDirWithFilesOrThrow(@NotNull
                                             String... dirs)
                                      throws IORuntimeException

Removes the supplied directories and throws if any remain. Tests usually invoke this at start-up to clean the output of a previous run.

Parameters:

dirs - directories to remove

Throws:

IORuntimeException

deleteDirWithFilesOrThrow

public static void deleteDirWithFilesOrThrow(@NotNull
                                             File... dirs)
                                      throws IORuntimeException

Variant accepting File objects. Behaviour matches the string-based method.

Parameters:

dirs - directories to remove

Throws:

IORuntimeException

deleteDirWithFilesOrWait

public static void deleteDirWithFilesOrWait(long timeoutMs,
                                            @NotNull
                                            @NotNull File dir)

Polls until the supplied directory disappears or the timeout elapses. Useful when another process might still hold a handle to a file.

Parameters:

timeoutMs - maximum time in milliseconds to wait

dir - directory to remove

Throws:

AssertionError - if the directory remains after the timeout

writeFile

public static void writeFile(@NotNull
                             @NotNull String filename,
                             byte[] bytes)
                      throws IOException

Writes the given byte array to a file with the specified name.

Parameters:

filename - The name of the file to write to

bytes - The byte array to write to the file

Throws:

IOException - If an I/O error occurs

urlFor

@NotNull
public static @NotNull URL urlFor(Class<?> clazz,
                                           String name)
                                    throws FileNotFoundException

Ensures that directory is absent or deleted, awaits for given timeout if necessary.

Parameters:

clazz - file to use to determine the class loader.

name - Name of the file to find.

Returns:

URL of the file.

Throws:

FileNotFoundException - if the file is not found.

urlFor

@NotNull
public static @NotNull URL urlFor(ClassLoader classLoader,
                                           String name)
                                    throws FileNotFoundException

Ensures that directory is absent or deleted, awaits for given timeout if necessary.

Parameters:

classLoader - Class loader to use to find the file.

name - Name of the file to find.

Returns:

URL of the file.

Throws:

FileNotFoundException - if the file is not found.

open

public static InputStream open(URL url)
                        throws IOException

Creates and returns a new InputStream from the provided url.

It is up to the caller to close the returned InputStream after being used. If this method throws, no resources remain open.

Gzip detection uses URL.getPath() so that a query string (for example, .../foo.gz?token=abc) does not defeat the suffix match. Unexpected throwables from GZIPInputStream's constructor (for example, OutOfMemoryError) are deliberately allowed to propagate after the underlying stream has been closed; they are not silently swallowed.

Parameters:

url - to create an InputStream from

Returns:

an InputStream

Throws:

IOException - if the URL cannot be opened

readFile

public static byte[] readFile(Class<?> clazz,
                              @NotNull
                              @NotNull String name)
                       throws IOException

This method first looks for the file in the classpath. If this is not found it appends the suffix .gz and looks again in the classpath to see if it is present. If it is still not found it looks for the file on the file system. If it not found it appends the suffix .gz and looks again on the file system. If it still not found a FileNotFoundException is thrown.

Parameters:

clazz - file to use to determine the class loader.

name - Name of the file

Returns:

A byte[] containing the contents of the file

Throws:

IOException - FileNotFoundException thrown if file is not found

readAsBytes

public static byte[] readAsBytes(InputStream is)
                          throws IOException

Reads data from an input stream and returns it as a byte array.

Parameters:

is - The input stream to read data from

Returns:

A byte array containing the data read from the input stream

Throws:

IOException - If an I/O error occurs

tempName

@NotNull
public static @NotNull String tempName(@NotNull
                                                @NotNull String filename)

Creates a temporary name for a file by appending the system's current nanosecond time to the file name.

Parameters:

filename - The original file name

Returns:

A temporary file name

createDirectories

public static void createDirectories(Path dir)
                              throws IOException

Creates a directory at the specified path, including any necessary but nonexistent parent directories.

Parameters:

dir - The path of the directory to create

Throws:

IOException - If an I/O error occurs

createTempFile

public static File createTempFile(String s)

Creates a temporary file in a temporary directory with the specified name.

Parameters:

s - The name of the temporary file to create

Returns:

The temporary file that was created

createTempDirectory

public static Path createTempDirectory(String s)

Creates a temporary directory with the specified name.

Parameters:

s - The name of the temporary directory to create

Returns:

The path to the temporary directory that was created

unmonitor

public static void unmonitor(Object t)

Stops the monitoring of the specified object.

Parameters:

t - The object to stop monitoring

clean

public static void clean(ByteBuffer bb)

Calls the system's Cleaner Service to clean the given ByteBuffer.

Parameters:

bb - The ByteBuffer to clean

isDirectBuffer

public static boolean isDirectBuffer(ByteBuffer byteBuffer)

Checks if a ByteBuffer is a direct buffer.

Parameters:

byteBuffer - The ByteBuffer to check

Returns:

true if the ByteBuffer is a direct buffer, false otherwise

addressFor

public static long addressFor(ByteBuffer byteBuffer)

Gets the memory address of the given ByteBuffer.

Parameters:

byteBuffer - The ByteBuffer for which to get the memory address

Returns:

The memory address of the ByteBuffer

normaliseIOStatus

public static int normaliseIOStatus(int n)

Normalizes an I/O operation status code.

Parameters:

n - The I/O status code to normalize

Returns:

The normalized I/O status code

destroyProcess

public static void destroyProcess(@NotNull
                                  @NotNull Process process)

Best-effort cleanup of a child Process: waits up to one second for the process to exit, calls Process.destroy(), waits up to another second, and finally escalates to Process.destroyForcibly() if the child is still alive. When destruction is needed the pipe streams are closed so file descriptors are not held until the Process object is reaped. If the current thread is interrupted while waiting, the interrupt flag is restored before destruction is attempted.

Parameters:

process - the child process to tear down; must not be null