Package com.sun.jna

Class Native

  • All Implemented Interfaces:
    Version
    public final class Native
extends Object
implements Version
    Provides generation of invocation plumbing for a defined native library interface. Also provides various utilities for native operations.

    getTypeMapper(java.lang.Class<?>) and getStructureAlignment(java.lang.Class<?>) are provided to avoid having to explicitly pass these parameters to Structures, which would require every Structure which requires custom mapping or alignment to define a constructor and pass parameters to the superclass. To avoid lots of boilerplate, the base Structure constructor figures out these properties based on its enclosing interface.

    Library Loading

    When JNA classes are loaded, the native shared library (jnidispatch) is loaded as well. An attempt is made to load it from the any paths defined in jna.boot.library.path (if defined), then the system library path using System.loadLibrary(java.lang.String), unless jna.nosys=true. If not found, the appropriate library will be extracted from the class path (into a temporary directory if found within a jar file) and loaded from there, unless jna.noclasspath=true. If your system has additional security constraints regarding execution or load of files (SELinux, for example), you should probably install the native library in an accessible location and configure your system accordingly, rather than relying on JNA to extract the library from its own jar file.

    To avoid the automatic unpacking (in situations where you want to force a failure if the JNA native library is not properly installed on the system), set the system property jna.nounpack=true.

    While this class and its corresponding native library are loaded, the system property jna.loaded will be set. The property will be cleared when native support has been unloaded (i.e. the Native class and its underlying native support has been GC'd).

    NOTE: all native functions are provided within this class to ensure that all other JNA-provided classes and objects are GC'd and/or finalized/disposed before this class is disposed and/or removed from memory (most notably Memory and any other class which by default frees its resources in a finalizer).

    Native Library Loading

    Native libraries loaded via load(Class) may be found in several locations.
    Author:
    Todd Fast, todd.fast@sun.com, twall@users.sf.net
    See Also:
    Library

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      static interface  Native.ffi_callback  

    • Method Summary

      All Methods Static Methods Concrete Methods Deprecated Methods 
      Modifier and Type Method Description
      (package private) static void close​(long handle)
      Close the given native library.
      (package private) static long createNativeCallback​(Callback callback, Method method, Class<?>[] parameterTypes, Class<?> returnType, int callingConvention, int flags, String encoding)
      Create a native trampoline to delegate execution to the Java callback.
      (package private) static boolean deleteLibrary​(File lib)
      Remove any automatically unpacked native library.
      static void detach​(boolean detach)
      Indicate whether the JVM should detach the current native thread when the current Java code finishes execution.
      static File extractFromResourcePath​(String name)
      Attempt to extract a native library from the current resource path, using the current thread context class loader.
      static File extractFromResourcePath​(String name, ClassLoader loader)
      Attempt to extract a native library from the resource path using the given class loader.
      static void ffi_call​(long cif, long fptr, long resp, long args)
      Make an FFI function call.
      static void ffi_free_closure​(long closure)  
      static long ffi_prep_cif​(int abi, int nargs, long ffi_return_type, long ffi_types)
      Create a new cif structure.
      static long ffi_prep_closure​(long cif, Native.ffi_callback cb)  
      (package private) static Class<?> findDirectMappedClass​(Class<?> cls)
      Find the nearest enclosing class with native methods.
      (package private) static Class<?> findEnclosingLibraryClass​(Class<?> cls)
      Find the library interface corresponding to the given class.
      (package private) static long findSymbol​(long handle, String name)  
      static void free​(long ptr)
      Call the real native free
      (package private) static void freeNativeCallback​(long ptr)
      Free the given callback trampoline.
      (package private) static byte getByte​(Pointer pointer, long baseaddr, long offset)  
      (package private) static byte[] getBytes​(String s)  
      (package private) static byte[] getBytes​(String s, String encoding)  
      (package private) static byte[] getBytes​(String s, Charset charset)  
      static Callback.UncaughtExceptionHandler getCallbackExceptionHandler()  
      (package private) static Class<?> getCallingClass()
      Try to determine the class context in which a register(String) call was made.
      (package private) static char getChar​(Pointer pointer, long baseaddr, long offset)  
      static long getComponentID​(Component c)
      Utility method to get the native window ID for a heavyweight Java Component as a long value.
      static Pointer getComponentPointer​(Component c)
      Utility method to get the native window pointer for a heavyweight Java Component as a Pointer value.
      static String getDefaultStringEncoding()  
      static Pointer getDirectBufferPointer​(Buffer b)
      Convert a direct Buffer into a Pointer.
      (package private) static ByteBuffer getDirectByteBuffer​(Pointer pointer, long addr, long offset, long length)  
      (package private) static double getDouble​(Pointer pointer, long baseaddr, long offset)  
      (package private) static float getFloat​(Pointer pointer, long baseaddr, long offset)  
      (package private) static int getInt​(Pointer pointer, long baseaddr, long offset)  
      static int getLastError()
      Retrieve last error set by the OS.
      static Map<String,​Object> getLibraryOptions​(Class<?> type)
      Return the preferred native library configuration options for the given class.
      (package private) static long getLong​(Pointer pointer, long baseaddr, long offset)  
      static int getNativeSize​(Class<?> cls)
      Returns the native size for a given Java class.
      static int getNativeSize​(Class<?> type, Object value)  
      (package private) static Pointer getPointer​(long addr)  
      (package private) static short getShort​(Pointer pointer, long baseaddr, long offset)  
      (package private) static String getSignature​(Class<?> cls)  
      (package private) static String getString​(Pointer pointer, long offset)  
      (package private) static String getString​(Pointer pointer, long offset, String encoding)  
      (package private) static byte[] getStringBytes​(Pointer pointer, long baseaddr, long offset)  
      static String getStringEncoding​(Class<?> cls)  
      static int getStructureAlignment​(Class<?> cls)  
      (package private) static File getTempDir()
      Obtain a directory suitable for writing JNA-specific temporary files.
      (package private) static Pointer getTerminationFlag​(Thread t)  
      static TypeMapper getTypeMapper​(Class<?> cls)
      Return the preferred TypeMapper for the given native interface.
      static String getWebStartLibraryPath​(String libName)
      If running web start, determine the location of a given native library.
      (package private) static String getWideString​(Pointer pointer, long baseaddr, long offset)  
      (package private) static long getWindowHandle0​(Component c)  
      static long getWindowID​(Window w)
      Utility method to get the native window ID for a Java Window as a long value.
      static Pointer getWindowPointer​(Window w)
      Utility method to get the native window pointer for a Java Window as a Pointer value.
      (package private) static long indexOf​(Pointer pointer, long baseaddr, long offset, byte value)  
      (package private) static int initialize_ffi_type​(long type_info)
      Returns the size (calculated by libffi) of the given type.
      (package private) static double invokeDouble​(Function function, long fp, int callFlags, Object[] args)
      Call the native function.
      (package private) static float invokeFloat​(Function function, long fp, int callFlags, Object[] args)
      Call the native function.
      (package private) static int invokeInt​(Function function, long fp, int callFlags, Object[] args)
      Call the native function.
      (package private) static long invokeLong​(Function function, long fp, int callFlags, Object[] args)
      Call the native function.
      (package private) static Object invokeObject​(Function function, long fp, int callFlags, Object[] args)
      Call the native function, returning a Java Object.
      (package private) static long invokePointer​(Function function, long fp, int callFlags, Object[] args)
      Call the native function.
      (package private) static Structure invokeStructure​(Function function, long fp, int callFlags, Object[] args, Structure s)
      Call the native function, returning a struct by value.
      (package private) static void invokeVoid​(Function function, long fp, int callFlags, Object[] args)
      Call the native function.
      (package private) static boolean isCompatibleVersion​(String expectedVersion, String nativeVersion)
      Version string must have the structure .. a bugfix change in the native code increments revision, the minor is incremented for backwards compatible changes and the major version is changed for backwards incompatbile changes.
      static boolean isProtected()
      Returns whether protection is enabled.
      static boolean isSupportedNativeType​(Class<?> cls)  
      (package private) static boolean isUnpacked​(File file)
      Identify temporary files unpacked from classpath jar files.
      static <T extends Library>
      T      		 load​(Class<T> interfaceClass)
      Map a library interface to the current process, providing the explicit interface class.
      static <T extends Library>
      T      		 load​(Class<T> interfaceClass, Map<String,​?> options)
      Map a library interface to the current process, providing the explicit interface class.
      static <T extends Library>
      T      		 load​(String name, Class<T> interfaceClass)
      Map a library interface to the given shared library, providing the explicit interface class.
      static <T extends Library>
      T      		 load​(String name, Class<T> interfaceClass, Map<String,​?> options)
      Load a library interface from the given shared library, providing the explicit interface class and a map of options for the library.
      static <T> T loadLibrary​(Class<T> interfaceClass)
      Deprecated.
      static <T> T loadLibrary​(Class<T> interfaceClass, Map<String,​?> options)
      Deprecated.
      static <T> T loadLibrary​(String name, Class<T> interfaceClass)
      Deprecated.
      static <T> T loadLibrary​(String name, Class<T> interfaceClass, Map<String,​?> options)
      Deprecated.
      static void main​(String[] args)
      Prints JNA library details to the console.
      static long malloc​(long size)
      Call the real native malloc
      (package private) static void markTemporaryFile​(File file)
      Perform cleanup of automatically unpacked native shared library.
      (package private) static long open​(String name)
      Open the requested native library with default options.
      (package private) static long open​(String name, int flags)
      Open the requested native library with the specified platform-specific otions.
      (package private) static void read​(Pointer pointer, long baseaddr, long offset, byte[] buf, int index, int length)  
      (package private) static void read​(Pointer pointer, long baseaddr, long offset, char[] buf, int index, int length)  
      (package private) static void read​(Pointer pointer, long baseaddr, long offset, double[] buf, int index, int length)  
      (package private) static void read​(Pointer pointer, long baseaddr, long offset, float[] buf, int index, int length)  
      (package private) static void read​(Pointer pointer, long baseaddr, long offset, int[] buf, int index, int length)  
      (package private) static void read​(Pointer pointer, long baseaddr, long offset, long[] buf, int index, int length)  
      (package private) static void read​(Pointer pointer, long baseaddr, long offset, short[] buf, int index, int length)  
      static void register​(NativeLibrary lib)
      When called from a class static initializer, maps all native methods found within that class to native libraries via the JNA raw calling interface.
      static void register​(Class<?> cls, NativeLibrary lib)
      When called from a class static initializer, maps all native methods found within that class to native libraries via the JNA raw calling interface.
      static void register​(Class<?> cls, String libName)
      When called from a class static initializer, maps all native methods found within that class to native libraries via the JNA raw calling interface.
      static void register​(String libName)
      When called from a class static initializer, maps all native methods found within that class to native libraries via the JNA raw calling interface.
      static boolean registered​(Class<?> cls)  
      (package private) static void removeTemporaryFiles()
      Remove all marked temporary files in the given directory.
      (package private) static String replace​(String s1, String s2, String str)  
      (package private) static void setByte​(Pointer pointer, long baseaddr, long offset, byte value)  
      static void setCallbackExceptionHandler​(Callback.UncaughtExceptionHandler eh)
      Set the default handler invoked when a callback throws an uncaught exception.
      static void setCallbackThreadInitializer​(Callback cb, CallbackThreadInitializer initializer)
      Set a thread initializer for the given callback.
      (package private) static void setChar​(Pointer pointer, long baseaddr, long offset, char value)  
      (package private) static void setDouble​(Pointer pointer, long baseaddr, long offset, double value)  
      (package private) static void setFloat​(Pointer pointer, long baseaddr, long offset, float value)  
      (package private) static void setInt​(Pointer pointer, long baseaddr, long offset, int value)  
      static void setLastError​(int code)
      Set the OS last error code.
      (package private) static void setLong​(Pointer pointer, long baseaddr, long offset, long value)  
      (package private) static void setMemory​(Pointer pointer, long baseaddr, long offset, long length, byte value)  
      (package private) static void setPointer​(Pointer pointer, long baseaddr, long offset, long value)  
      static void setProtected​(boolean enable)
      Set whether native memory accesses are protected from invalid accesses.
      (package private) static void setShort​(Pointer pointer, long baseaddr, long offset, short value)  
      (package private) static void setWideString​(Pointer pointer, long baseaddr, long offset, String value)  
      static Library synchronizedLibrary​(Library library)
      Returns a synchronized (thread-safe) library backed by the specified library.
      static byte[] toByteArray​(String s)  
      static byte[] toByteArray​(String s, String encoding)  
      static byte[] toByteArray​(String s, Charset charset)  
      static char[] toCharArray​(String s)  
      static String toString​(byte[] buf)
      Obtain a Java String from the given native byte array.
      static String toString​(byte[] buf, String encoding)
      Obtain a Java String from the given native byte array, using the given encoding.
      static String toString​(byte[] buf, Charset charset)
      Obtain a Java String from the given native byte array, using the given encoding.
      static String toString​(char[] buf)
      Obtain a Java String from the given native wchar_t array.
      static List<String> toStringList​(char[] buf)
      Converts a "list" of strings each null terminated into a List of String values.
      static List<String> toStringList​(char[] buf, int offset, int len)
      Converts a "list" of strings each null terminated into a List of String values.
      static void unregister()
      Remove all native mappings for the calling class.
      static void unregister​(Class<?> cls)
      Remove all native mappings for the given class.
      (package private) static void write​(Pointer pointer, long baseaddr, long offset, byte[] buf, int index, int length)  
      (package private) static void write​(Pointer pointer, long baseaddr, long offset, char[] buf, int index, int length)  
      (package private) static void write​(Pointer pointer, long baseaddr, long offset, double[] buf, int index, int length)  
      (package private) static void write​(Pointer pointer, long baseaddr, long offset, float[] buf, int index, int length)  
      (package private) static void write​(Pointer pointer, long baseaddr, long offset, int[] buf, int index, int length)  
      (package private) static void write​(Pointer pointer, long baseaddr, long offset, long[] buf, int index, int length)  
      (package private) static void write​(Pointer pointer, long baseaddr, long offset, short[] buf, int index, int length)  

    • Field Detail

      • DEFAULT_CHARSET

        public static final Charset DEFAULT_CHARSET

      • DEFAULT_ENCODING

        public static final String DEFAULT_ENCODING

      • DEBUG_LOAD

        public static final boolean DEBUG_LOAD

      • DEBUG_JNA_LOAD

        public static final boolean DEBUG_JNA_LOAD

      • jnidispatchPath

        static String jnidispatchPath

      • POINTER_SIZE

        public static final int POINTER_SIZE
        The size of a native pointer (void*) on the current platform, in bytes.

      • LONG_SIZE

        public static final int LONG_SIZE
        Size of a native long type, in bytes.

      • WCHAR_SIZE

        public static final int WCHAR_SIZE
        Size of a native wchar_t type, in bytes.

      • SIZE_T_SIZE

        public static final int SIZE_T_SIZE
        Size of a native size_t type, in bytes.

      • BOOL_SIZE

        public static final int BOOL_SIZE
        Size of a native bool type (C99 and later), in bytes.

      • LONG_DOUBLE_SIZE

        public static final int LONG_DOUBLE_SIZE
        Size of a native long double type (C99 and later), in bytes.

      • MAX_ALIGNMENT

        static final int MAX_ALIGNMENT

      • MAX_PADDING

        static final int MAX_PADDING

      • CB_HAS_INITIALIZER

        static final int CB_HAS_INITIALIZER
        Indicates whether the callback has an initializer.
        See Also:
        Constant Field Values

      • CB_OPTION_DIRECT

        static final int CB_OPTION_DIRECT
        Use direct mapping for callback.
        See Also:
        Constant Field Values

      • CB_OPTION_IN_DLL

        static final int CB_OPTION_IN_DLL
        Return a DLL-resident fucntion pointer.
        See Also:
        Constant Field Values

    • Method Detail

      • isCompatibleVersion

        static boolean isCompatibleVersion​(String expectedVersion,
                                   String nativeVersion)
        Version string must have the structure .. a bugfix change in the native code increments revision, the minor is incremented for backwards compatible changes and the major version is changed for backwards incompatbile changes.
        Parameters:
        expectedVersion -
        nativeVersion -
        Returns:
        true if nativeVersion describes a version compatible to expectedVersion

      • deleteLibrary

        static boolean deleteLibrary​(File lib)
        Remove any automatically unpacked native library. This will fail on windows, which disallows removal of any file that is still in use, so an alternative is required in that case. Mark the file that could not be deleted, and attempt to delete any temporaries on next startup. Do NOT force the class loader to unload the native library, since that introduces issues with cleaning up any extant JNA bits (e.g. Memory) which may still need use of the library before shutdown.

      • setProtected

        public static void setProtected​(boolean enable)
        Set whether native memory accesses are protected from invalid accesses. This should only be set true when testing or debugging, and should not be considered reliable or robust for applications where JNA native calls are occurring on multiple threads. Protected mode will be automatically set if the system property jna.protected has a value of "true" when the JNA library is first loaded.

        If not supported by the underlying platform, this setting will have no effect.

        NOTE: On platforms which support signals (non-Windows), JNA uses signals to trap errors. This may interfere with the JVM's own use of signals. When protected mode is enabled, you should make use of the jsig library, if available (see Signal Chaining). In short, set the environment variable LD_PRELOAD to the path to libjsig.so in your JRE lib directory (usually ${java.home}/lib/${os.arch}/libjsig.so) before launching your Java application.

      • isProtected

        public static boolean isProtected()
        Returns whether protection is enabled. Check the result of this method after calling setProtected(true) to determine if this platform supports protecting memory accesses.

      • getWindowID

        public static long getWindowID​(Window w)
                        throws HeadlessException
        Utility method to get the native window ID for a Java Window as a long value. This method is primarily for X11-based systems, which use an opaque XID (usually long int) to identify windows.
        Throws:
        HeadlessException - if the current VM is running headless

      • getComponentID

        public static long getComponentID​(Component c)
                           throws HeadlessException
        Utility method to get the native window ID for a heavyweight Java Component as a long value. This method is primarily for X11-based systems, which use an opaque XID (usually long int) to identify windows.
        Throws:
        HeadlessException - if the current VM is running headless

      • getWindowPointer

        public static Pointer getWindowPointer​(Window w)
                                throws HeadlessException
        Utility method to get the native window pointer for a Java Window as a Pointer value. This method is primarily for w32, which uses the HANDLE type (actually void *) to identify windows.
        Throws:
        HeadlessException - if the current VM is running headless

      • getComponentPointer

        public static Pointer getComponentPointer​(Component c)
                                   throws HeadlessException
        Utility method to get the native window pointer for a heavyweight Java Component as a Pointer value. This method is primarily for w32, which uses the HWND type (actually void *) to identify windows.
        Throws:
        HeadlessException - if the current VM is running headless

      • getWindowHandle0

        static long getWindowHandle0​(Component c)

      • toString

        public static String toString​(byte[] buf)
        Obtain a Java String from the given native byte array. If there is no NUL terminator, the String will comprise the entire array. The encoding is obtained from getDefaultStringEncoding().
        Parameters:
        buf - The buffer containing the encoded bytes
        See Also:
        toString(byte[], String)

      • toString

        public static String toString​(byte[] buf,
                              String encoding)
        Obtain a Java String from the given native byte array, using the given encoding. If there is no NUL terminator, the String will comprise the entire array.

        Usage note: This function assumes, that buf holds a char array. This means only single-byte encodings are supported.

        Parameters:
        buf - The buffer containing the encoded bytes. Must not be null.
        encoding - The encoding name - if null then the platform default encoding will be used

      • toString

        public static String toString​(byte[] buf,
                              Charset charset)
        Obtain a Java String from the given native byte array, using the given encoding. If there is no NUL terminator, the String will comprise the entire array.

        Usage note: This function assumes, that buf holds a char array. This means only single-byte encodings are supported.

        Parameters:
        buf - The buffer containing the encoded bytes. Must not be null.
        charset - The charset to decode buf. Must not be null.

      • toString

        public static String toString​(char[] buf)
        Obtain a Java String from the given native wchar_t array. If there is no NUL terminator, the String will comprise the entire array.
        Parameters:
        buf - The buffer containing the characters

      • toStringList

        public static List<String> toStringList​(char[] buf)
        Converts a "list" of strings each null terminated into a List of String values. The end of the list is signaled by an extra NULL value at the end or by the end of the buffer.
        Parameters:
        buf - The buffer containing the strings
        Returns:
        A List of all the strings in the buffer
        See Also:
        toStringList(char[], int, int)

      • toStringList

        public static List<String> toStringList​(char[] buf,
                                        int offset,
                                        int len)
        Converts a "list" of strings each null terminated into a List of String values. The end of the list is signaled by an extra NULL value at the end or by the end of the data.
        Parameters:
        buf - The buffer containing the strings
        offset - Offset to start parsing
        len - The total characters to parse
        Returns:
        A List of all the strings in the buffer

      • load

        public static <T extends Library> T load​(Class<T> interfaceClass)
        Map a library interface to the current process, providing the explicit interface class. Native libraries loaded via this method may be found in several locations.
        Type Parameters:
        T - Type of expected wrapper
        Parameters:
        interfaceClass - The implementation wrapper interface
        Returns:
        an instance of the requested interface, mapped to the current process.
        Throws:
        UnsatisfiedLinkError - if the library cannot be found or dependent libraries are missing.

      • load

        public static <T extends Library> T load​(Class<T> interfaceClass,
                                         Map<String,​?> options)
        Map a library interface to the current process, providing the explicit interface class. Any options provided for the library are cached and associated with the library and any of its defined structures and/or functions. Native libraries loaded via this method may be found in several locations.
        Type Parameters:
        T - Type of expected wrapper
        Parameters:
        interfaceClass - The implementation wrapper interface
        options - Map of library options
        Returns:
        an instance of the requested interface, mapped to the current process.
        Throws:
        UnsatisfiedLinkError - if the library cannot be found or dependent libraries are missing.
        See Also:
        load(String, Class, Map)

      • load

        public static <T extends Library> T load​(String name,
                                         Class<T> interfaceClass)
        Map a library interface to the given shared library, providing the explicit interface class. If name is null, attempts to map onto the current process. Native libraries loaded via this method may be found in several locations.
        Type Parameters:
        T - Type of expected wrapper
        Parameters:
        name - Library base name
        interfaceClass - The implementation wrapper interface
        Returns:
        an instance of the requested interface, mapped to the indicated native library.
        Throws:
        UnsatisfiedLinkError - if the library cannot be found or dependent libraries are missing.
        See Also:
        load(String, Class, Map)

      • load

        public static <T extends Library> T load​(String name,
                                         Class<T> interfaceClass,
                                         Map<String,​?> options)
        Load a library interface from the given shared library, providing the explicit interface class and a map of options for the library. If no library options are detected the map is interpreted as a map of Java method names to native function names.

        If name is null, attempts to map onto the current process. Native libraries loaded via this method may be found in several locations.

        Type Parameters:
        T - Type of expected wrapper
        Parameters:
        name - Library base name
        interfaceClass - The implementation wrapper interface
        options - Map of library options
        Returns:
        an instance of the requested interface, mapped to the indicated native library.
        Throws:
        UnsatisfiedLinkError - if the library cannot be found or dependent libraries are missing.

      • loadLibrary

        @Deprecated
public static <T> T loadLibrary​(Class<T> interfaceClass)
        Deprecated.
        Provided for improved compatibility between JNA 4.X and 5.X
        See Also:
        load(java.lang.Class)

      • findEnclosingLibraryClass

        static Class<?> findEnclosingLibraryClass​(Class<?> cls)
        Find the library interface corresponding to the given class. Checks all ancestor classes and interfaces for a declaring class which implements Library.
        Parameters:
        cls - The given class
        Returns:
        The enclosing class

      • getLibraryOptions

        public static Map<String,​Object> getLibraryOptions​(Class<?> type)
        Return the preferred native library configuration options for the given class. First attempts to load any field of the interface type within the interface mapping, then checks the cache for any specified library options. If none found, a set of library options will be generated from the fields (by order of precedence) OPTIONS (a Map), TYPE_MAPPER (a TypeMapper), STRUCTURE_ALIGNMENT (an Integer), and STRING_ENCODING (a String).
        Parameters:
        type - The type class
        Returns:
        The options map

      • getDefaultStringEncoding

        public static String getDefaultStringEncoding()
        Returns:
        The default string encoding. Returns the value of the system property jna.encoding or DEFAULT_ENCODING.

      • getStructureAlignment

        public static int getStructureAlignment​(Class<?> cls)
        Parameters:
        cls - The native interface type
        Returns:
        The preferred structure alignment for the given native interface.
        See Also:
        Library.OPTION_STRUCTURE_ALIGNMENT

      • getBytes

        static byte[] getBytes​(String s)
        Parameters:
        s - The input string
        Returns:
        A byte array corresponding to the given String. The encoding used is obtained from getDefaultStringEncoding().

      • getBytes

        static byte[] getBytes​(String s,
                       String encoding)
        Parameters:
        s - The string. Must not be null.
        encoding - The encoding - if null then the default platform encoding is used
        Returns:
        A byte array corresponding to the given String, using the given encoding. If the encoding is not found default to the platform native encoding.

      • getBytes

        static byte[] getBytes​(String s,
                       Charset charset)
        Parameters:
        s - The string. Must not be null.
        charset - The charset used to encode s. Must not be null.
        Returns:
        A byte array corresponding to the given String, using the given charset.

      • toByteArray

        public static byte[] toByteArray​(String s,
                                 String encoding)
        Parameters:
        s - The string. Must not be null.
        encoding - The encoding - if null then the default platform encoding is used
        Returns:
        A NUL-terminated byte buffer equivalent to the given String, using the given encoding.
        See Also:
        getBytes(String, String)

      • toByteArray

        public static byte[] toByteArray​(String s,
                                 Charset charset)
        Parameters:
        s - The string. Must not be null.
        charset - The charset used to encode s. Must not be null.
        Returns:
        A NUL-terminated byte buffer equivalent to the given String, using the given charset.
        See Also:
        getBytes(String, String)

      • toCharArray

        public static char[] toCharArray​(String s)
        Parameters:
        s - The string
        Returns:
        A NUL-terminated wide character buffer equivalent to the given string.

      • isUnpacked

        static boolean isUnpacked​(File file)
        Identify temporary files unpacked from classpath jar files.

      • extractFromResourcePath

        public static File extractFromResourcePath​(String name)
                                    throws IOException
        Attempt to extract a native library from the current resource path, using the current thread context class loader.
        Parameters:
        name - Base name of native library to extract. May also be an absolute resource path (i.e. starts with "/"), in which case the no transformations of the library name are performed. If only the base name is given, the resource path is attempted both with and without Platform.RESOURCE_PREFIX, after mapping the library name via NativeLibrary.mapSharedLibraryName(String).
        Returns:
        File indicating extracted resource on disk
        Throws:
        IOException - if resource not found

      • extractFromResourcePath

        public static File extractFromResourcePath​(String name,
                                           ClassLoader loader)
                                    throws IOException
        Attempt to extract a native library from the resource path using the given class loader.
        Parameters:
        name - Base name of native library to extract. May also be an absolute resource path (i.e. starts with "/"), in which case the no transformations of the library name are performed. If only the base name is given, the resource path is attempted both with and without Platform.RESOURCE_PREFIX, after mapping the library name via NativeLibrary.mapSharedLibraryName(String).
        loader - Class loader to use to load resources
        Returns:
        File indicating extracted resource on disk
        Throws:
        IOException - if resource not found

      • getLastError

        public static int getLastError()
        Retrieve last error set by the OS. This corresponds to GetLastError() on Windows, and errno on most other platforms. The value is preserved per-thread, but whether the original value is per-thread depends on the underlying OS.

        An alternative method of obtaining the last error result is to declare your mapped method to throw LastErrorException instead. If a method's signature includes a throw of LastErrorException, the last error will be set to zero before the native call and a LastErrorException will be raised if the last error value is non-zero after the call, regardless of the actual returned value from the native function.

      • setLastError

        public static void setLastError​(int code)
        Set the OS last error code. The value will be saved on a per-thread basis.

      • synchronizedLibrary

        public static Library synchronizedLibrary​(Library library)
        Returns a synchronized (thread-safe) library backed by the specified library. This wrapping will prevent simultaneous invocations of any functions mapped to a given NativeLibrary. Note that the native library may still be sensitive to being called from different threads.

        Parameters:
        library - the library to be "wrapped" in a synchronized library.
        Returns:
        a synchronized view of the specified library.

      • getWebStartLibraryPath

        public static String getWebStartLibraryPath​(String libName)
        If running web start, determine the location of a given native library. This value may be used to properly set jna.library.path so that JNA can load libraries identified by the <nativelib> tag in the JNLP configuration file. Returns null if the Web Start native library cache location can not be determined. Note that the path returned may be different for any given library name.

        Use System.getProperty("javawebstart.version") to detect whether your code is running under Web Start.

        Returns:
        null if unable to query the web start loader.
        Throws:
        UnsatisfiedLinkError - if the library can't be found by the Web Start class loader, which usually means it wasn't included as a <nativelib> resource in the JNLP file.

      • markTemporaryFile

        static void markTemporaryFile​(File file)
        Perform cleanup of automatically unpacked native shared library.

      • getTempDir

        static File getTempDir()
                throws IOException
        Obtain a directory suitable for writing JNA-specific temporary files. Override with jna.tmpdir
        Throws:
        IOException

      • removeTemporaryFiles

        static void removeTemporaryFiles()
                          throws IOException
        Remove all marked temporary files in the given directory.
        Throws:
        IOException

      • getNativeSize

        public static int getNativeSize​(Class<?> type,
                                Object value)
        Parameters:
        type - The Java class for which the native size is to be determined
        value - an instance of said class (if available)
        Returns:
        the native size of the given class, in bytes. For use with arrays.

      • getNativeSize

        public static int getNativeSize​(Class<?> cls)
        Returns the native size for a given Java class. Structures are assumed to be struct pointers unless they implement Structure.ByValue.
        Parameters:
        cls - The Java class
        Returns:
        The native size for the class

      • isSupportedNativeType

        public static boolean isSupportedNativeType​(Class<?> cls)
        Parameters:
        cls - The Java class
        Returns:
        true whether the given class is supported as a native argument type.

      • setCallbackExceptionHandler

        public static void setCallbackExceptionHandler​(Callback.UncaughtExceptionHandler eh)
        Set the default handler invoked when a callback throws an uncaught exception. If the given handler is null, the default handler will be reinstated.
        Parameters:
        eh - The default handler

      • getCallbackExceptionHandler

        public static Callback.UncaughtExceptionHandler getCallbackExceptionHandler()
        Returns:
        the current handler for callback uncaught exceptions.

      • register

        public static void register​(String libName)
        When called from a class static initializer, maps all native methods found within that class to native libraries via the JNA raw calling interface.
        Parameters:
        libName - library name to which functions should be bound

      • register

        public static void register​(NativeLibrary lib)
        When called from a class static initializer, maps all native methods found within that class to native libraries via the JNA raw calling interface.
        Parameters:
        lib - native library to which functions should be bound

      • findDirectMappedClass

        static Class<?> findDirectMappedClass​(Class<?> cls)
        Find the nearest enclosing class with native methods.

      • getCallingClass

        static Class<?> getCallingClass()
        Try to determine the class context in which a register(String) call was made.

      • setCallbackThreadInitializer

        public static void setCallbackThreadInitializer​(Callback cb,
                                                CallbackThreadInitializer initializer)
        Set a thread initializer for the given callback.
        Parameters:
        cb - The callback to invoke
        initializer - The thread initializer indicates desired thread configuration when the given Callback is invoked on a native thread not yet attached to the VM.

      • unregister

        public static void unregister()
        Remove all native mappings for the calling class. Should only be called if the class is no longer referenced and about to be garbage collected.

      • unregister

        public static void unregister​(Class<?> cls)
        Remove all native mappings for the given class. Should only be called if the class is no longer referenced and about to be garbage collected.

      • registered

        public static boolean registered​(Class<?> cls)
        Parameters:
        cls - The type Class
        Returns:
        whether the given class's native components are registered.

      • getSignature

        static String getSignature​(Class<?> cls)

      • register

        public static void register​(Class<?> cls,
                            String libName)
        When called from a class static initializer, maps all native methods found within that class to native libraries via the JNA raw calling interface. Uses the class loader of the given class to search for the native library in the resource path if it is not found in the system library load path or jna.library.path.
        Parameters:
        cls - Class with native methods to register
        libName - name of or path to native library to which functions should be bound

      • register

        public static void register​(Class<?> cls,
                            NativeLibrary lib)
        When called from a class static initializer, maps all native methods found within that class to native libraries via the JNA raw calling interface.
        Parameters:
        cls - Class with native methods to register
        lib - library to which functions should be bound

      • ffi_prep_cif

        public static long ffi_prep_cif​(int abi,
                                int nargs,
                                long ffi_return_type,
                                long ffi_types)
        Create a new cif structure.

      • ffi_call

        public static void ffi_call​(long cif,
                            long fptr,
                            long resp,
                            long args)
        Make an FFI function call.

      • ffi_prep_closure

        public static long ffi_prep_closure​(long cif,
                                    Native.ffi_callback cb)

      • ffi_free_closure

        public static void ffi_free_closure​(long closure)

      • initialize_ffi_type

        static int initialize_ffi_type​(long type_info)
        Returns the size (calculated by libffi) of the given type.

      • main

        public static void main​(String[] args)
        Prints JNA library details to the console.

      • freeNativeCallback

        static void freeNativeCallback​(long ptr)
        Free the given callback trampoline.

      • createNativeCallback

        static long createNativeCallback​(Callback callback,
                                 Method method,
                                 Class<?>[] parameterTypes,
                                 Class<?> returnType,
                                 int callingConvention,
                                 int flags,
                                 String encoding)
        Create a native trampoline to delegate execution to the Java callback.

      • invokeInt

        static int invokeInt​(Function function,
                     long fp,
                     int callFlags,
                     Object[] args)
        Call the native function.
        Parameters:
        function - Present to prevent the GC to collect the Function object prematurely
        fp - function pointer
        callFlags - calling convention to be used
        args - Arguments to pass to the native function
        Returns:
        The value returned by the target native function

      • invokeLong

        static long invokeLong​(Function function,
                       long fp,
                       int callFlags,
                       Object[] args)
        Call the native function.
        Parameters:
        function - Present to prevent the GC to collect the Function object prematurely
        fp - function pointer
        callFlags - calling convention to be used
        args - Arguments to pass to the native function
        Returns:
        The value returned by the target native function

      • invokeVoid

        static void invokeVoid​(Function function,
                       long fp,
                       int callFlags,
                       Object[] args)
        Call the native function.
        Parameters:
        function - Present to prevent the GC to collect the Function object prematurely
        fp - function pointer
        callFlags - calling convention to be used
        args - Arguments to pass to the native function

      • invokeFloat

        static float invokeFloat​(Function function,
                         long fp,
                         int callFlags,
                         Object[] args)
        Call the native function.
        Parameters:
        function - Present to prevent the GC to collect the Function object prematurely
        fp - function pointer
        callFlags - calling convention to be used
        args - Arguments to pass to the native function
        Returns:
        The value returned by the target native function

      • invokeDouble

        static double invokeDouble​(Function function,
                           long fp,
                           int callFlags,
                           Object[] args)
        Call the native function.
        Parameters:
        function - Present to prevent the GC to collect the Function object prematurely
        fp - function pointer
        callFlags - calling convention to be used
        args - Arguments to pass to the native function
        Returns:
        The value returned by the target native function

      • invokePointer

        static long invokePointer​(Function function,
                          long fp,
                          int callFlags,
                          Object[] args)
        Call the native function.
        Parameters:
        function - Present to prevent the GC to collect the Function object prematurely
        fp - function pointer
        callFlags - calling convention to be used
        args - Arguments to pass to the native function
        Returns:
        The value returned by the target native function

      • invokeStructure

        static Structure invokeStructure​(Function function,
                                 long fp,
                                 int callFlags,
                                 Object[] args,
                                 Structure s)
        Call the native function, returning a struct by value.
        Parameters:
        function - Present to prevent the GC to collect the Function object prematurely
        fp - function pointer
        callFlags - calling convention to be used
        args - Arguments to pass to the native function
        Returns:
        the passed-in Structure

      • invokeObject

        static Object invokeObject​(Function function,
                           long fp,
                           int callFlags,
                           Object[] args)
        Call the native function, returning a Java Object.
        Parameters:
        function - Present to prevent the GC to collect the Function object prematurely
        fp - function pointer
        callFlags - calling convention to be used
        args - Arguments to pass to the native function
        Returns:
        The returned Java Object

      • open

        static long open​(String name)
        Open the requested native library with default options.

      • open

        static long open​(String name,
                 int flags)
        Open the requested native library with the specified platform-specific otions.

      • close

        static void close​(long handle)
        Close the given native library.

      • findSymbol

        static long findSymbol​(long handle,
                       String name)

      • indexOf

        static long indexOf​(Pointer pointer,
                    long baseaddr,
                    long offset,
                    byte value)

      • read

        static void read​(Pointer pointer,
                 long baseaddr,
                 long offset,
                 byte[] buf,
                 int index,
                 int length)

      • read

        static void read​(Pointer pointer,
                 long baseaddr,
                 long offset,
                 short[] buf,
                 int index,
                 int length)

      • read

        static void read​(Pointer pointer,
                 long baseaddr,
                 long offset,
                 char[] buf,
                 int index,
                 int length)

      • read

        static void read​(Pointer pointer,
                 long baseaddr,
                 long offset,
                 int[] buf,
                 int index,
                 int length)

      • read

        static void read​(Pointer pointer,
                 long baseaddr,
                 long offset,
                 long[] buf,
                 int index,
                 int length)

      • read

        static void read​(Pointer pointer,
                 long baseaddr,
                 long offset,
                 float[] buf,
                 int index,
                 int length)

      • read

        static void read​(Pointer pointer,
                 long baseaddr,
                 long offset,
                 double[] buf,
                 int index,
                 int length)

      • write

        static void write​(Pointer pointer,
                  long baseaddr,
                  long offset,
                  byte[] buf,
                  int index,
                  int length)

      • write

        static void write​(Pointer pointer,
                  long baseaddr,
                  long offset,
                  short[] buf,
                  int index,
                  int length)

      • write

        static void write​(Pointer pointer,
                  long baseaddr,
                  long offset,
                  char[] buf,
                  int index,
                  int length)

      • write

        static void write​(Pointer pointer,
                  long baseaddr,
                  long offset,
                  int[] buf,
                  int index,
                  int length)

      • write

        static void write​(Pointer pointer,
                  long baseaddr,
                  long offset,
                  long[] buf,
                  int index,
                  int length)

      • write

        static void write​(Pointer pointer,
                  long baseaddr,
                  long offset,
                  float[] buf,
                  int index,
                  int length)

      • write

        static void write​(Pointer pointer,
                  long baseaddr,
                  long offset,
                  double[] buf,
                  int index,
                  int length)

      • getByte

        static byte getByte​(Pointer pointer,
                    long baseaddr,
                    long offset)

      • getChar

        static char getChar​(Pointer pointer,
                    long baseaddr,
                    long offset)

      • getShort

        static short getShort​(Pointer pointer,
                      long baseaddr,
                      long offset)

      • getInt

        static int getInt​(Pointer pointer,
                  long baseaddr,
                  long offset)

      • getLong

        static long getLong​(Pointer pointer,
                    long baseaddr,
                    long offset)

      • getFloat

        static float getFloat​(Pointer pointer,
                      long baseaddr,
                      long offset)

      • getDouble

        static double getDouble​(Pointer pointer,
                        long baseaddr,
                        long offset)

      • getPointer

        static Pointer getPointer​(long addr)

      • getWideString

        static String getWideString​(Pointer pointer,
                            long baseaddr,
                            long offset)

      • getString

        static String getString​(Pointer pointer,
                        long offset)

      • getStringBytes

        static byte[] getStringBytes​(Pointer pointer,
                             long baseaddr,
                             long offset)

      • setMemory

        static void setMemory​(Pointer pointer,
                      long baseaddr,
                      long offset,
                      long length,
                      byte value)

      • setByte

        static void setByte​(Pointer pointer,
                    long baseaddr,
                    long offset,
                    byte value)

      • setShort

        static void setShort​(Pointer pointer,
                     long baseaddr,
                     long offset,
                     short value)

      • setChar

        static void setChar​(Pointer pointer,
                    long baseaddr,
                    long offset,
                    char value)

      • setInt

        static void setInt​(Pointer pointer,
                   long baseaddr,
                   long offset,
                   int value)

      • setLong

        static void setLong​(Pointer pointer,
                    long baseaddr,
                    long offset,
                    long value)

      • setFloat

        static void setFloat​(Pointer pointer,
                     long baseaddr,
                     long offset,
                     float value)

      • setDouble

        static void setDouble​(Pointer pointer,
                      long baseaddr,
                      long offset,
                      double value)

      • setPointer

        static void setPointer​(Pointer pointer,
                       long baseaddr,
                       long offset,
                       long value)

      • setWideString

        static void setWideString​(Pointer pointer,
                          long baseaddr,
                          long offset,
                          String value)

      • getDirectByteBuffer

        static ByteBuffer getDirectByteBuffer​(Pointer pointer,
                                      long addr,
                                      long offset,
                                      long length)

      • malloc

        public static long malloc​(long size)
        Call the real native malloc
        Parameters:
        size - size of the memory to be allocated
        Returns:
        native address of the allocated memory block; zero if the allocation failed.

      • free

        public static void free​(long ptr)
        Call the real native free
        Parameters:
        ptr - native address to be freed; a value of zero has no effect, passing an already-freed pointer will cause pain.

      • detach

        public static void detach​(boolean detach)

        Indicate whether the JVM should detach the current native thread when the current Java code finishes execution. Generally this is used to avoid detaching native threads when it is known that a given thread will be relatively long-lived and call back to Java code frequently.

        This call is lightweight; it only results in an additional JNI crossing if the desired state changes from its last setting.
        Throws:
        IllegalStateException - if detach(true) is called on a thread created by the JVM.

      • getTerminationFlag

        static Pointer getTerminationFlag​(Thread t)