jna/www/PlatformLibrary.md

Platform Library

JNA includes platform.jar that has cross-platform mappings and mappings for a number of commonly used platform functions, including a large number of Win32 mappings as well as a set of utility classes that simplify native access. The code is tested and the utility interfaces ensure that native memory management is taken care of correctly.

Before you map your own functions, check the platform package documentation for an already mapped one.

Platform-specific structures are mapped by header. For example, ShlObj.h structures can be found in com.sun.jna.platform.win32.ShlObj. Platform functions are mapped by library. For example, Advapi32.dll functions can be found in com.sun.jna.platform.win32.Advapi32. Simplified interfaces (wrappers) for Advapi32.dll functions can be found in com.sun.jna.platform.win32.Advapi32Util.

Cross-platform functions and structures are implemented in com.sun.jna.platform. These currently include the following.

• FileMonitor: a cross-platform file system watcher
• FileUtils: a cross-platform set of file-related functions, such as move to the recycle bin
• KeyboardUtils: a cross-platform set of keyboard functions, such as finding out whether a key is pressed
• WindowUtils: a cross-platform set of window functions, providing non-rectangular shaped and transparent windows.

COM support

late-time-binding

JNA includes basic Microsoft COM support in the package com.sun.jna.platform.win32.COM.*. The COM support is being implemented with late-time-binding, vtable support is not yet available. The straightforward approach is to extend the class COMObject.class as base class for all COM enabled java applications.

• COMObject(String progId, boolean useActiveInstance): first parameter describes the ProgID (e.g. WinWord -> Word.Application), second parameter if a current running instance should be used.

• COMObject.oleMethod: provides the possability to call any kind of COM method like Properties and Methods. The 'oleMethod' should be used to create a COM method in the custom java wrapper,

e.g. (part of the MSWord sample)
this.oleMethod(OleAuto.DISPATCH_PROPERTYPUT, result, this.iDispatch, "Visible", new VARIANT(bVisible));

• ITypeLib.java: a wrapper for a TypeLib definition
• IUnknown.java: a wrapper for the IUnknown interface
• COMException.java: used as exception
• COMObject.java: base class for all COM enabled applications
• COMUtils.java: utility class
• IDispatch.java: a wrapper for the IDispatch interface
• IRecordInfo.java: a wrapper for the IRecordInfo interface
• ITypeComp.java: a wrapper for the ITypeComp interface
• ITypeInfo.java: a wrapper for the ITypeInfo interface, which describes a COM interface itself

Typelib parsing