Package com.sun.jna

Interface Library

All Known Subinterfaces:
Advapi32, Carbon, Cfgmgr32, CoreDLL, CoreFoundation, Crypt32, Cryptui, Ddeml, DiskArbitration, Dxva2, ExtAttr, GDI32, IOKit, IPHlpAPI, Kernel32, Kstat2, LibC, LibC, LibKstat, LibRT, MacFileUtils.FileManager, Mpr, Msi, Netapi32, NtDll, Ole32, OleAuto, OpenGL32, Pdh, Perfstat, PowrProf, Psapi, Rasapi32, Secur32, SetupApi, Shell32, ShellAPI, Shlwapi, StdCallLibrary, SystemB, Udev, User32, Version, W32APIOptions, Wevtapi, Wininet, Winsock2, Winspool, Wtsapi32, X11, X11.Xevie, X11.Xext, X11.Xrender, X11.XTest, XAttr, XAttr
All Known Implementing Classes:
AccCtrl
public interface Library
Derive from this interface for all native library definitions. Define an instance of your library like this: 

 MyNativeLibrary INSTANCE = (MyNativeLibrary)
     Native.load("mylib", MyNativeLibrary.class);

By convention, method names are identical to the native names, although you can map java names to different native names by providing a FunctionMapper as a value for key OPTION_FUNCTION_MAPPER in the options map passed to the Native.load(String, Class, Map) call.

Although the names for structures and structure fields may be chosen arbitrarily, they should correspond as closely as possible to the native definitions. The same is true for parameter names.

This interface supports multiple, concurrent invocations of any library methods on the Java side. Check your library documentation for its multi-threading requirements on the native side. If a library is not safe for simultaneous multi-threaded access, consider using Native.synchronizedLibrary(com.sun.jna.Library) to prevent simultaneous multi-threaded access to the native code.

Optional fields
Interface options will be automatically propagated to structures defined within the library provided a call to Native.load(String,Class,Map) is made prior to instantiating any of those structures. One common way of ensuring this is to declare an INSTANCE field in the interface which holds the load result.

OPTIONS (an instance of Map), TYPE_MAPPER (an instance of TypeMapper), STRUCTURE_ALIGNMENT (one of the alignment types defined in Structure), and STRING_ENCODING (a String) may also be defined. If no instance of the interface has been instantiated, these fields will be used to determine customization settings for structures and methods defined within the interface.

Author:
Todd Fast, [email protected], Timothy Wall, [email protected]

  • Field Details

    • OPTION_TYPE_MAPPER

      static final String OPTION_TYPE_MAPPER
      Option key for a TypeMapper for the library.
      See Also:

    • OPTION_FUNCTION_MAPPER

      static final String OPTION_FUNCTION_MAPPER
      Option key for a FunctionMapper for the library.
      See Also:

    • OPTION_INVOCATION_MAPPER

      static final String OPTION_INVOCATION_MAPPER
      Option key for an InvocationMapper for the library.
      See Also:

    • OPTION_STRUCTURE_ALIGNMENT

      static final String OPTION_STRUCTURE_ALIGNMENT
      Option key for structure alignment type (Integer), which should be one of the predefined alignment types in Structure.
      See Also:

    • OPTION_STRING_ENCODING

      static final String OPTION_STRING_ENCODING

      Option key for per-library String encoding. This affects conversions between Java unicode and native (const char*) strings (as arguments or Structure fields).

      Defaults to Native.getDefaultStringEncoding().
      See Also:

    • OPTION_ALLOW_OBJECTS

      static final String OPTION_ALLOW_OBJECTS
      Option key for a boolean flag to allow any Java class instance as a parameter. If no type mapper is found, the object is passed as a pointer. NOTE: This is for use with raw JNI interactions via the JNIEnv data structure.
      See Also:

    • OPTION_CALLING_CONVENTION

      static final String OPTION_CALLING_CONVENTION
      Calling convention for the entire library.
      See Also:

    • OPTION_OPEN_FLAGS

      static final String OPTION_OPEN_FLAGS
      Flags to use when opening the native library (see Native.open(String,int))
      See Also:

    • OPTION_CLASSLOADER

      static final String OPTION_CLASSLOADER

      Class loader to use when searching for native libraries on the resource path (classpath). If not provided the current thread's context class loader is used.

      If extracted from the resource path (i.e. bundled in a jar file), the loaded library's lifespan will mirror that of the class loader, which means you can use the same library in isolated contexts without conflict.
      See Also:

    • OPTION_SYMBOL_PROVIDER

      static final String OPTION_SYMBOL_PROVIDER
      Supports a custom symbol provider for the NativeLibrary (see SymbolProvider)
      See Also: