JNA API 3.2.4

com.sun.jna

Interface Library

  • All Known Subinterfaces:
    CLibrary, GDI32, Kernel32, Shell32, StdCallLibrary, User32, W32API, X11, X11.Xevie, X11.Xext, X11.Xrender, X11.XTest


    public interface Library
    Derive from this interface for all native library definitions. Define an instance of your library like this:
     MyNativeLibrary INSTANCE = (MyNativeLibrary)
         Native.loadLibrary("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.loadLibrary(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.loadLibrary(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 loadLibrary result.

    OPTIONS (an instance of Map), TYPE_MAPPER (an instance of TypeMapper) and STRUCTURE_ALIGNMENT (one of the alignment types defined in Structure) 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, todd.fast@sun.com, Timothy Wall, twalljava@dev.java.net
    • Field Detail

      • OPTION_STRUCTURE_ALIGNMENT

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

        static final java.lang.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:
        Constant Field Values
      • OPTION_CALLING_CONVENTION

        static final java.lang.String OPTION_CALLING_CONVENTION
        Calling convention for the entire library.
        See Also:
        Constant Field Values
JNA API 3.2.4

Copyright © 2007-2009 Timothy Wall. All Rights Reserved.