Package org.apache.nifi.nar

Class AbstractNativeLibHandlingClassLoader

java.lang.Object

java.lang.ClassLoader

java.security.SecureClassLoader

java.net.URLClassLoader

org.apache.nifi.nar.AbstractNativeLibHandlingClassLoader

All Implemented Interfaces:

Closeable, AutoCloseable, OSUtil

Direct Known Subclasses:

NarClassLoader

public abstract class AbstractNativeLibHandlingClassLoader
extends URLClassLoader
implements OSUtil

An extension of URLClassLoader that can load native libraries from a predefined list of directories as well as from those that are defined by the java.library.path system property. Once a library is found an OS-handled temporary copy is created and cached to maintain consistency and classloader isolation. This classloader handles the native library loading when the library is being loaded by its logical name (System.loadLibrary(String) / Runtime.loadLibrary(String) calls). For loading a native library by its absolute path, see LoadNativeLibAspect.

Field Summary

Fields

Modifier and Type	Field	Description
private final org.slf4j.Logger	logger
protected final List<File>	nativeLibDirList	Directories in which to look for native libraries
protected final Map<String,Path>	nativeLibNameToPath	Used to cache (the paths of) temporary copies of loaded libraries
private final String	tmpLibFilePrefix	Used as prefix when creating the temporary copies of libraries

Fields inherited from interface org.apache.nifi.nar.OSUtil

OS

Constructor Summary

Constructors

Constructor	Description
AbstractNativeLibHandlingClassLoader(URL[] urls, ClassLoader parent, List<File> initialNativeLibDirList, String tmpLibFilePrefix)
AbstractNativeLibHandlingClassLoader(URL[] urls, List<File> initialNativeLibDirList, String tmpLibFilePrefix)

Method Summary

Modifier and Type	Method	Description
private List<File>	buildNativeLibDirList(List<File> initialNativeLibDirList)
protected Path	createTempCopy(String libname, String libraryOriginalPathString)
String	findLibrary(String libname)
protected String	findLibrary(String libname, File nativeLibDir)
protected String	getJavaLibraryPath()
protected Set<File>	getUsrLibDirs()
static File	toDir(File fileOrDir)

Methods inherited from class java.net.URLClassLoader

addURL, close, definePackage, findClass, findResource, findResources, getPermissions, getResourceAsStream, getURLs, newInstance, newInstance

Methods inherited from class java.security.SecureClassLoader

defineClass, defineClass

Methods inherited from class java.lang.ClassLoader

clearAssertionStatus, defineClass, defineClass, defineClass, defineClass, definePackage, findClass, findLoadedClass, findResource, findSystemClass, getClassLoadingLock, getDefinedPackage, getDefinedPackages, getName, getPackage, getPackages, getParent, getPlatformClassLoader, getResource, getResources, getSystemClassLoader, getSystemResource, getSystemResourceAsStream, getSystemResources, getUnnamedModule, isRegisteredAsParallelCapable, loadClass, loadClass, registerAsParallelCapable, resolveClass, resources, setClassAssertionStatus, setDefaultAssertionStatus, setPackageAssertionStatus, setSigners

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.nifi.nar.OSUtil

isOsLinuxUnix, isOsMac, isOsWindows

Field Details

logger

private final org.slf4j.Logger logger

nativeLibDirList

protected final List<File> nativeLibDirList

Directories in which to look for native libraries

nativeLibNameToPath

protected final Map<String,Path> nativeLibNameToPath

Used to cache (the paths of) temporary copies of loaded libraries

tmpLibFilePrefix

private final String tmpLibFilePrefix

Used as prefix when creating the temporary copies of libraries

Constructor Details

AbstractNativeLibHandlingClassLoader

public AbstractNativeLibHandlingClassLoader(URL[] urls,
 List<File> initialNativeLibDirList,
 String tmpLibFilePrefix)

AbstractNativeLibHandlingClassLoader

public AbstractNativeLibHandlingClassLoader(URL[] urls,
 ClassLoader parent,
 List<File> initialNativeLibDirList,
 String tmpLibFilePrefix)

Method Details

toDir

public static File toDir(File fileOrDir)

findLibrary

public String findLibrary(String libname)

Overrides:

findLibrary in class ClassLoader

getUsrLibDirs

protected Set<File> getUsrLibDirs()

getJavaLibraryPath

protected String getJavaLibraryPath()

createTempCopy

protected Path createTempCopy(String libname,
 String libraryOriginalPathString)

findLibrary

protected String findLibrary(String libname,
 File nativeLibDir)

buildNativeLibDirList

private List<File> buildNativeLibDirList(List<File> initialNativeLibDirList)