org.xerial.snappy

Class SnappyLoader

java.lang.Object

org.xerial.snappy.SnappyLoader

public class SnappyLoader
extends java.lang.Object

Internal only - Do not use this class. This class loads a native library of snappy-java (snappyjava.dll, libsnappy.so, etc.) according to the user platform (os.name and os.arch). The natively compiled libraries bundled to snappy-java contain the codes of the original snappy and JNI programs to access Snappy.

In default, no configuration is required to use snappy-java, but you can load your own native library created by 'make native' command.

This SnappyLoader searches for native libraries (snappyjava.dll, libsnappy.so, etc.) in the following order:

1. If system property org.xerial.snappy.use.systemlib is set to true, lookup folders specified by java.lib.path system property (This is the default path that JVM searches for native libraries)
2. (System property: org.xerial.snappy.lib.path)/(System property: org.xerial.lib.name)
3. One of the libraries embedded in snappy-java-(version).jar extracted into (System property: java.io.tempdir). If org.xerial.snappy.tempdir is set, use this folder instead of java.io.tempdir.

If you do not want to use folder java.io.tempdir, set the System property org.xerial.snappy.tempdir. For example, to use /tmp/leo as a temporary folder to copy native libraries, use -D option of JVM:

 
 java -Dorg.xerial.snappy.tempdir="/tmp/leo" ...
 
 

Field Summary

Fields

Modifier and Type	Field and Description
private static SnappyNative	api
private static boolean	isLoaded
static java.lang.String	KEY_SNAPPY_DISABLE_BUNDLED_LIBS
static java.lang.String	KEY_SNAPPY_LIB_NAME
static java.lang.String	KEY_SNAPPY_LIB_PATH
static java.lang.String	KEY_SNAPPY_TEMPDIR
static java.lang.String	KEY_SNAPPY_USE_SYSTEMLIB
private static java.io.File	nativeLibFile
static java.lang.String	SNAPPY_SYSTEM_PROPERTIES_FILE

Constructor Summary

Constructors

Constructor and Description
SnappyLoader()

Method Summary

Modifier and Type	Method and Description
(package private) static void	cleanUpExtractedNativeLib()
private static boolean	contentsEquals(java.io.InputStream in1, java.io.InputStream in2)
private static java.io.File	extractLibraryFile(java.lang.String libFolderForCurrentOS, java.lang.String libraryFileName, java.lang.String targetFolder) Extract the specified library file to the target folder
(package private) static java.io.File	findNativeLibrary()
static java.lang.String	getVersion() Get the snappy-java version by reading pom.properties embedded in jar.
private static boolean	hasResource(java.lang.String path)
(package private) static SnappyNative	load()
private static void	loadNativeLibrary() Load a native library of snappy-java
private static void	loadSnappySystemProperties() load system properties when configuration file of the name SNAPPY_SYSTEM_PROPERTIES_FILE is found
(package private) static void	setApi(SnappyNative nativeCode) Set the api instance.

Methods inherited from class java.lang.Object

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

Field Detail

SNAPPY_SYSTEM_PROPERTIES_FILE

public static final java.lang.String SNAPPY_SYSTEM_PROPERTIES_FILE

See Also:

Constant Field Values

KEY_SNAPPY_LIB_PATH

public static final java.lang.String KEY_SNAPPY_LIB_PATH

See Also:

Constant Field Values

KEY_SNAPPY_LIB_NAME

public static final java.lang.String KEY_SNAPPY_LIB_NAME

See Also:

Constant Field Values

KEY_SNAPPY_TEMPDIR

public static final java.lang.String KEY_SNAPPY_TEMPDIR

See Also:

Constant Field Values

KEY_SNAPPY_USE_SYSTEMLIB

public static final java.lang.String KEY_SNAPPY_USE_SYSTEMLIB

See Also:

Constant Field Values

KEY_SNAPPY_DISABLE_BUNDLED_LIBS

public static final java.lang.String KEY_SNAPPY_DISABLE_BUNDLED_LIBS

See Also:

Constant Field Values

isLoaded

private static volatile boolean isLoaded

api

private static volatile SnappyNative api

nativeLibFile

private static java.io.File nativeLibFile

Constructor Detail

SnappyLoader

public SnappyLoader()

Method Detail

cleanUpExtractedNativeLib

static void cleanUpExtractedNativeLib()

setApi

static void setApi(SnappyNative nativeCode)

Set the api instance.

Parameters:

nativeCode -

loadSnappySystemProperties

private static void loadSnappySystemProperties()

load system properties when configuration file of the name SNAPPY_SYSTEM_PROPERTIES_FILE is found

load

static SnappyNative load()

loadNativeLibrary

private static void loadNativeLibrary()

Load a native library of snappy-java

contentsEquals

private static boolean contentsEquals(java.io.InputStream in1,
                                      java.io.InputStream in2)
                               throws java.io.IOException

Throws:

java.io.IOException

extractLibraryFile

private static java.io.File extractLibraryFile(java.lang.String libFolderForCurrentOS,
                                               java.lang.String libraryFileName,
                                               java.lang.String targetFolder)

Extract the specified library file to the target folder

Parameters:

libFolderForCurrentOS -

libraryFileName -

targetFolder -

Returns:

findNativeLibrary

static java.io.File findNativeLibrary()

hasResource

private static boolean hasResource(java.lang.String path)

getVersion

public static java.lang.String getVersion()

Get the snappy-java version by reading pom.properties embedded in jar. This version data is used as a suffix of a dll file extracted from the jar.

Returns:

the version string