com.ibm.cloud.objectstorage.services.aspera.transfer

Class AsperaLibraryLoader

java.lang.Object

com.ibm.cloud.objectstorage.services.aspera.transfer.AsperaLibraryLoader

public final class AsperaLibraryLoader
extends Object

Utility class to support extracting and loading native Aspera assets (ascp, dynamic libraries, configuration) from the cos-aspera dependency

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	AsperaLibraryLoader.AsperaLibraryLoadException An exception that represents a failed attempt to load the Aspera library

Field Summary

Fields

Modifier and Type	Field and Description
protected static org.apache.commons.logging.Log	log

Constructor Summary

Constructors

Constructor and Description
AsperaLibraryLoader()

Method Summary

Modifier and Type	Method and Description
static JarFile	createJar() Creates an instance of JarFile which references the Aspera library
static void	extractFile(JarFile jar, JarEntry entry, File destPath) Extracts a jar entry from a jar file to a target location on the local file system
static void	extractJar(JarFile jar, File extractedLocation) Creates a 1:1 copy of all contents from a jar file to the specified location on the local filesystem
static String	jarVersion(JarFile jar) Determines the version associated with this jar
static String	load() Prepares and loads the Aspera library in preparation for its use.
static void	loadLibrary(File extractedPath, List<String> candidates) Loads a dynamic library into the JVM from a list of candidates
static List<String>	osLibs() Determine which os the jvm is running on

Methods inherited from class java.lang.Object

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

Field Detail

log

protected static org.apache.commons.logging.Log log

Constructor Detail

AsperaLibraryLoader

public AsperaLibraryLoader()

Method Detail

load

public static String load()

Prepares and loads the Aspera library in preparation for its use. May conditionally extract Aspera library jar contents to a location on the local filesystem, determined by a combination of the User's home directory and library version. Loads the underlying dynamic library for use by the Aspera library Java bindings

createJar

public static JarFile createJar()
                         throws IOException,
                                URISyntaxException

Creates an instance of JarFile which references the Aspera library

Returns:

Aspera Library jar file

Throws:

IOException - if unable to create a JarFile reference

URISyntaxException - if the location to the Aspera library is invalid

jarVersion

public static String jarVersion(JarFile jar)
                         throws IOException

Determines the version associated with this jar

Parameters:

jar - Source jar to query version information from

Returns:

The source jar's version

Throws:

IOException - if unable to successfully query source jar

extractJar

public static void extractJar(JarFile jar,
                              File extractedLocation)
                       throws IOException

Creates a 1:1 copy of all contents from a jar file to the specified location on the local filesystem

Parameters:

jar - The source jar to extract contents from

extractedLocation - The target location for extracted jar contents

Throws:

IOException - if jar extraction fails IO

extractFile

public static void extractFile(JarFile jar,
                               JarEntry entry,
                               File destPath)
                        throws IOException

Extracts a jar entry from a jar file to a target location on the local file system

Parameters:

jar - The jar in which the desired file resides

entry - The desired entry (file) to extract from the jar

destPath - The target location to extract the jar entry to

Throws:

IOException - if any IO failure occurs during file extraction

osLibs

public static List<String> osLibs()

Determine which os the jvm is running on

Returns:

the os specific list of native files to load

loadLibrary

public static void loadLibrary(File extractedPath,
                               List<String> candidates)

Loads a dynamic library into the JVM from a list of candidates

Parameters:

extractedPath - The base directory where candidate dynamic libraries reside

candidates - A list of candidate dynamic library names for various platforms