android nio,GitHub - lukhnos/nnio: An NIO.2 substitute for Android

NNIO: A Java NIO.2 Substitute Library

NNIO ("Not NIO") is an experimental porting strategy for code that depends on

Java NIO.2 API (for example, classes in the java.nio.file package). It

provides a replacement subset of NIO.2 under a different package name. The

subset is implemented with the pre-NIO.2 file API, and as a result should be

usable to code using a language level lower than Java 7 or built for Android.

To use NNIO, you have to substitute NIO.2 package names with NNIO ones. For

example, java.nio.file.Path becomes org.lukhnos.nnio.file.Path.

This is a work in progress. I only plan to backport a very small subset of

NIO.2, and there are a lot different backporting strategies to explore. Open

questions include how to integrate with an app's existing build system,

especially if code generation or preprocessing is required (so as to facilitate

the global substitution of NIO.2 package names). In addition, not all NIO.2

API is backportable, as some of those (such as the file system API) requires

native implementations. It's currently a non-goal for NNIO to include any

native code.

Quick Start

Have your project depend on nnio. Suppose you use Gradle:

repositories {

mavenCentral()

}

dependencies {

compile 'org.lukhnos:nnio:0.2'

}

Then replace your java.nio.file and java.nio.channels imports with

org.lukhnos.nnio.file and org.lukhnos.nnio.channels respectively. If you

run into errors such as missing classes or methods, this means the items in

question are not backported to nnio. :)

Project Goal

This project aims to backport commonly used NIO.2 classes and methods to allow

Android apps to include code that depends on NIO.2.

Non-Goals

Anything that requires native implementation (for example, getting file

creation time, which java.io.File does not support) is a non-goal for this

library.

In addition, a sound file system library is hard to implement. This project

does not aim to address every fine aspect -- the goal is to backport enough

code to make it practical to use code that depends on NIO.2. It's up to the

library user (you) to make sure that the operations are safe and correct to

your need and standard. It's also a non-goal to make the library work on

Windows file system.

Classes Supported

Please note that while Files and Path have a larger coverage, a lot of the

classes listed here are stubs.

org.lukhnos.nnio.channels.AsynchronousChannel

org.lukhnos.nnio.channels.AsynchronousFileChannel

org.lukhnos.nnio.channels.CompletionHandler

org.lukhnos.nnio.file.AccessDeniedException

org.lukhnos.nnio.file.AccessMode

org.lukhnos.nnio.file.AtomicMoveNotSupportedException

org.lukhnos.nnio.file.attribute.AttributeView

org.lukhnos.nnio.file.attribute.BasicFileAttributes

org.lukhnos.nnio.file.attribute.BasicFileAttributeView

org.lukhnos.nnio.file.attribute.FileAttribute

org.lukhnos.nnio.file.attribute.FileAttributeView

org.lukhnos.nnio.file.attribute.FileStoreAttributeView

org.lukhnos.nnio.file.attribute.FileTime

org.lukhnos.nnio.file.attribute.UserPrincipalLookupService

org.lukhnos.nnio.file.CopyOption

org.lukhnos.nnio.file.DirectoryStream

org.lukhnos.nnio.file.FileAlreadyExistsException

org.lukhnos.nnio.file.Files

org.lukhnos.nnio.file.FileStore

org.lukhnos.nnio.file.FileSystem

org.lukhnos.nnio.file.FileSystemException

org.lukhnos.nnio.file.FileSystems

org.lukhnos.nnio.file.FileVisitor

org.lukhnos.nnio.file.FileVisitResult

org.lukhnos.nnio.file.InvalidPathException

org.lukhnos.nnio.file.LinkOption

org.lukhnos.nnio.file.NoSuchFileException

org.lukhnos.nnio.file.OpenOption

org.lukhnos.nnio.file.Path

org.lukhnos.nnio.file.PathMatcher

org.lukhnos.nnio.file.Paths

org.lukhnos.nnio.file.ProviderMismatchException

org.lukhnos.nnio.file.SimpleFileVisitor

org.lukhnos.nnio.file.spi.FileSystemProvider

org.lukhnos.nnio.file.StandardCopyOption

org.lukhnos.nnio.file.StandardOpenOption

org.lukhnos.nnio.file.WatchEvent

org.lukhnos.nnio.file.WatchKey

org.lukhnos.nnio.file.WatchService

A sepearte util class, org.lukhnos.nnio.channels.utils.FileChannelUtils, is

provided to supply the stand-in for FileChannel.open(), which is often not

available in the environments that nnio intends to support.

Note on Testing

The tests use NIO.2, but during the compile time, a Gradle task generates a

version of the tests that have all java.nio.file imports substituted to

org.lukhnos.nnio.file (and similarly for java.nio.channels), and each test

file has a corresponding Generated- prefixed test. Both versions are built

and tested together.