NativeLibrary (JNA API)

java.lang.Object
- com.sun.jna.NativeLibrary

```
public class NativeLibrary
extends Object
```
Provides management of native library resources. One instance of this class corresponds to a single loaded native library. May also be used to map to the current process (see getProcess()).
Library Search Paths A search for a given library will scan the following locations:
1. jna.library.path User-customizable path
2. jna.platform.library.path Platform-specific paths
3. On OSX, ~/Library/Frameworks, /Library/Frameworks, and /System/Library/Frameworks will be searched for a framework with a name corresponding to that requested. Absolute paths to frameworks are also accepted, either ending at the framework name (sans ".framework") or the full path to the framework shared library (e.g. CoreServices.framework/CoreServices).
4. Context class loader classpath. Deployed native libraries may be installed on the classpath under ${os-prefix}/LIBRARY_FILENAME, where ${os-prefix} is the OS/Arch prefix returned by Platform.getNativeLibraryResourcePrefix(). If bundled in a jar file, the resource will be extracted to jna.tmpdir for loading, and later removed (but only if jna.nounpack is false or not set).
You may set the system property jna.debug_load=true to make JNA print the steps of its library search to the console.
Author:

Wayne Meissner, split library loading from Function.java, twall

Field Summary

Fields
Modifier and Type Field and Description

(package private) int callFlags

(package private) Map<String,?> options

Fields
Modifier and Type	Field and Description
`(package private) int`	`callFlags`
`(package private) Map<String,?>`	`options`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`static void`	`addSearchPath(String libraryName, String path)` Add a path to search for the specified library, ahead of any system paths.
`void`	`dispose()` Close the native library we're mapped to.
`(package private) static void`	`disposeAll()` Close all open native libraries.
`protected void`	`finalize()` Close the library when it is no longer referenced.
`File`	`getFile()` Returns the file on disk corresponding to this NativeLibrary instance.
`Function`	`getFunction(String functionName)` Create a new `Function` that is linked with a native function that follows the NativeLibrary's calling convention.
`Function`	`getFunction(String functionName, int callFlags)` Create a new `Function` that is linked with a native function that follows a given calling flags.
`Function`	`getFunction(String functionName, int callFlags, String encoding)` Create a new `Function` that is linked with a native function that follows a given calling flags.
`(package private) Function`	`getFunction(String name, Method method)` Create a new `Function` that is linked with a native function that follows the NativeLibrary's calling convention.
`Pointer`	`getGlobalVariableAddress(String symbolName)` Look up the given global variable within this library.
`static NativeLibrary`	`getInstance(String libraryName)` Returns an instance of NativeLibrary for the specified name.
`static NativeLibrary`	`getInstance(String libraryName, ClassLoader classLoader)` Returns an instance of NativeLibrary for the specified name.
`static NativeLibrary`	`getInstance(String libraryName, Map<String,?> libraryOptions)` Returns an instance of NativeLibrary for the specified name.
`String`	`getName()` Returns the simple name of this library.
`Map<String,?>`	`getOptions()`
`static NativeLibrary`	`getProcess()` Returns an instance of NativeLibrary which refers to the current process.
`static NativeLibrary`	`getProcess(Map<String,?> options)` Returns an instance of NativeLibrary which refers to the current process.
`(package private) long`	`getSymbolAddress(String name)` Used by the Function class to locate a symbol
`(package private) static String`	`mapSharedLibraryName(String libName)` Similar to `System.mapLibraryName(java.lang.String)`, except that it maps to standard shared library formats rather than specifically JNI formats.
`(package private) static String`	`matchFramework(String libraryName)` Look for a matching framework (OSX)
`(package private) static String`	`matchLibrary(String libName, List<String> searchPath)` matchLibrary() is very Linux specific.
`(package private) static double`	`parseVersion(String ver)`
`String`	`toString()`

Methods inherited from class java.lang.Object
clone, equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - callFlags
```
final int callFlags
```
  - options
```
final Map<String,?> options
```
- Method Detail
  - matchFramework
```
static String matchFramework(String libraryName)
```
    Look for a matching framework (OSX)
  - getInstance
```
public static final NativeLibrary getInstance(String libraryName)
```
    Returns an instance of NativeLibrary for the specified name. The library is loaded if not already loaded. If already loaded, the existing instance is returned.
    More than one name may map to the same NativeLibrary instance; only a single instance will be provided for any given unique file path.
    
    Parameters:
    
    libraryName - The library name to load. This can be short form (e.g. "c"), an explicit version (e.g. "libc.so.6"), or the full path to the library (e.g. "/lib/libc.so.6").
  - getInstance
```
public static final NativeLibrary getInstance(String libraryName,
                                              ClassLoader classLoader)
```
    Returns an instance of NativeLibrary for the specified name. The library is loaded if not already loaded. If already loaded, the existing instance is returned.
    More than one name may map to the same NativeLibrary instance; only a single instance will be provided for any given unique file path.
    
    Parameters:
    
    libraryName - The library name to load. This can be short form (e.g. "c"), an explicit version (e.g. "libc.so.6"), or the full path to the library (e.g. "/lib/libc.so.6").
    
    classLoader - The class loader to use to load the native library. This only affects library loading when the native library is included somewhere in the classpath, either bundled in a jar file or as a plain file within the classpath.
  - getInstance
```
public static final NativeLibrary getInstance(String libraryName,
                                              Map<String,?> libraryOptions)
```
    Returns an instance of NativeLibrary for the specified name. The library is loaded if not already loaded. If already loaded, the existing instance is returned.
    More than one name may map to the same NativeLibrary instance; only a single instance will be provided for any given unique file path.
    
    Parameters:
    
    libraryName - The library name to load. This can be short form (e.g. "c"), an explicit version (e.g. "libc.so.6" or "QuickTime.framework/Versions/Current/QuickTime"), or the full (absolute) path to the library (e.g. "/lib/libc.so.6").
    
    libraryOptions - Native library options for the given library (see Library).
  - getProcess
```
public static final NativeLibrary getProcess()
```
    Returns an instance of NativeLibrary which refers to the current process. This is useful for accessing functions which were already mapped by some other mechanism, without having to reference or even know the exact name of the native library.
  - getProcess
```
public static final NativeLibrary getProcess(Map<String,?> options)
```
    Returns an instance of NativeLibrary which refers to the current process. This is useful for accessing functions which were already mapped by some other mechanism, without having to reference or even know the exact name of the native library.
  - addSearchPath
```
public static final void addSearchPath(String libraryName,
                                       String path)
```
    Add a path to search for the specified library, ahead of any system paths. This is similar to setting jna.library.path, but only extends the search path for a single library.
    
    Parameters:
    
    libraryName - The name of the library to use the path for
    
    path - The path to use when trying to load the library
  - getFunction
```
public Function getFunction(String functionName)
```
    Create a new Function that is linked with a native function that follows the NativeLibrary's calling convention.
    The allocated instance represents a pointer to the named native function from the library.
    
    Parameters:
    
    functionName - Name of the native function to be linked with
    
    Throws:
    
    UnsatisfiedLinkError - if the function is not found
  - getFunction
```
Function getFunction(String name,
                     Method method)
```
    Create a new Function that is linked with a native function that follows the NativeLibrary's calling convention.
    The allocated instance represents a pointer to the named native function from the library.
    
    Parameters:
    
    name - Name of the native function to be linked with. Uses a function mapper option if one was provided to transform the name.
    
    method - Method to which the native function is to be mapped
    
    Throws:
    
    UnsatisfiedLinkError - if the function is not found
  - getFunction
```
public Function getFunction(String functionName,
                            int callFlags)
```
    Create a new Function that is linked with a native function that follows a given calling flags.
    
    Parameters:
    
    functionName - Name of the native function to be linked with
    
    callFlags - Flags affecting the function invocation
    
    Throws:
    
    UnsatisfiedLinkError - if the function is not found
  - getFunction
```
public Function getFunction(String functionName,
                            int callFlags,
                            String encoding)
```
    Create a new Function that is linked with a native function that follows a given calling flags.
    
    Parameters:
    
    functionName - Name of the native function to be linked with
    
    callFlags - Flags affecting the function invocation
    
    encoding - Encoding to use to convert between Java and native strings.
    
    Throws:
    
    UnsatisfiedLinkError - if the function is not found
  - getOptions
```
public Map<String,?> getOptions()
```
    Returns:
    
    this native library instance's options.
  - getGlobalVariableAddress
```
public Pointer getGlobalVariableAddress(String symbolName)
```
    Look up the given global variable within this library.
    
    Parameters:
    
    symbolName -
    
    Returns:
    
    Pointer representing the global variable address
    
    Throws:
    
    UnsatisfiedLinkError - if the symbol is not found
  - getSymbolAddress
```
long getSymbolAddress(String name)
```
    Used by the Function class to locate a symbol
    
    Throws:
    
    UnsatisfiedLinkError - if the symbol can't be found
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object
  - getName
```
public String getName()
```
    Returns the simple name of this library.
  - getFile
```
public File getFile()
```
    Returns the file on disk corresponding to this NativeLibrary instance. If this NativeLibrary represents the current process, this function will return null.
  - finalize
```
protected void finalize()
```
    Close the library when it is no longer referenced.
    
    Overrides:
    
    finalize in class Object
  - disposeAll
```
static void disposeAll()
```
    Close all open native libraries.
  - dispose
```
public void dispose()
```
    Close the native library we're mapped to.
  - mapSharedLibraryName
```
static String mapSharedLibraryName(String libName)
```
    Similar to System.mapLibraryName(java.lang.String), except that it maps to standard shared library formats rather than specifically JNI formats.
    
    Parameters:
    
    libName - base (undecorated) name of library
  - matchLibrary
```
static String matchLibrary(String libName,
                           List<String> searchPath)
```
    matchLibrary() is very Linux specific. It is here to deal with the case where /usr/lib/libc.so does not exist, or it is not a valid symlink to a versioned file (e.g. /lib/libc.so.6).
  - parseVersion
```
static double parseVersion(String ver)
```

Class NativeLibrary

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

callFlags

options

Method Detail

matchFramework

getInstance

getInstance

getInstance

getProcess

getProcess

addSearchPath

getFunction

getFunction

getFunction

getFunction

getOptions

getGlobalVariableAddress

getSymbolAddress

toString

getName

getFile

finalize

disposeAll

dispose

mapSharedLibraryName

matchLibrary

parseVersion