Name: path-utils
Owner: Hammer Lab
Description: Scala convenience-wrapper for java.nio.file.Path
Created: 2017-04-01 23:24:08.0
Updated: 2017-04-03 16:42:16.0
Pushed: 2018-01-15 00:25:35.0
Homepage: null
Size: 46
Language: Scala
GitHub Committers
User | Most Recent Commit | # Commits |
---|
Other Committers
User | Most Recent Commit | # Commits |
---|
Serializable wrapper for java.nio.file.Path
Filesystem-path convenience methods and bug-fixes:
rt hammerlab.path._
path = Path("") // current directory; URIs and Strings accepted
.exists // true
/ 'src list // list children of src dir: Iterator(src/main,src/test)
src = path / 'src // "src" subdir
exists // true
/ 'foo exists // false
h / 'src / 'test walk) filter (_.isFile)
terator(
src/test/resources/log4j.properties,
src/test/resources/META-INF/services/java.nio.file.spi.FileSystemProvider,
src/test/scala/org/hammerlab/paths/PathTest.scala
Self-explanatory methods:
def inputStream: InputStream
def outputStream: OutputStream
def read: String
def readBytes: Array[Byte]
def write(String)
def writeLines(Iterable[String])
def lines: Iterator[String]
def size: Long
Path
s are Serializable
, delegating to the SerializablePath
proxy, which serializes them as URI
s.
Interacting with Java NIO FileSystemProviders from Scala is broken; see scala/bug#10247.
Path
s from this repo have hooks to lazily initialize and tweak the FileSystemProvider initialization code to resolve these problems; see FileSystems.scala.
There is also fix for a missing newByteChannel
implementation in the JRE's default implementation of JarFileSystemProvider
; use of Path
s replaces it with a custom JarFileSystemProvider
with this issue resolved.
As an example, try downloading the Google Cloud Storage NIO connector JAR, and querying for the existence and size of a public file:
-O lib/gcs-nio.jar http://search.maven.org/remotecontent?filepath=com/google/cloud/google-cloud-nio/0.28.0-alpha/google-cloud-nio-0.28.0-alpha-shaded.jar
console
rt hammerlab.path._
index = Path("gs://gcp-public-data-landsat/index.csv.gz")
x.exists // true
x.size // 476118237
In contrast, trying the equivalent using vanilla Java NIO paths fails:
rt java._, nio.file._, net._
uri = new URI("gs://gcp-public-data-landsat/index.csv.gz")
s.get(uri)
ava.nio.file.FileSystemNotFoundException: Provider "gs" not installed
at java.nio.file.Paths.get(Paths.java:147)
... 42 elided
(test this in a fresh sbt console
, as initializing a hammerlab Path
fixes the providers in that JVM)