WindowsPaths.java

package systextil.commons.io.path;

import java.io.File;

import com.sun.jna.Library;
import com.sun.jna.Native;
import com.sun.jna.NativeMapped;
import com.sun.jna.PointerType;
import com.sun.jna.win32.W32APIOptions;

/*package*/ class WindowsPaths extends SystemPaths {
	
	@Override
	public File getCommonAppData(String appName) {		
		return join(getPath(Shell32.CSIDL_COMMON_APPDATA), appName);
	}

	@Override
	public File getLocalAppData(String appName) {
		return join(getPath(Shell32.CSIDL_LOCAL_APPDATA), appName);
	}

	private synchronized String getPath(int pathType) {
		 HWND hwndOwner = null;
	 int nFolder = pathType;
	 HANDLE hToken = null;
	 int dwFlags = Shell32.SHGFP_TYPE_CURRENT;
	 char[] pszPath = new char[Shell32.MAX_PATH];
	 int hResult = Shell32.INSTANCE.SHGetFolderPath(hwndOwner, nFolder, hToken, dwFlags, pszPath);

	 if (Shell32.S_OK == hResult) {
	     String path = new String(pszPath);
	     int len = path.indexOf('\0');
	     return path.substring(0, len);
	 } else {
	     throw new RuntimeException("Unable to load path. Error code: " + hResult);
	 }

	}


	private class HANDLE extends PointerType implements NativeMapped {}
  	private class HWND extends HANDLE {}

  	private interface Shell32 extends Library {

      		static final int MAX_PATH = 260;
	      	static final int CSIDL_LOCAL_APPDATA = 0x001c;
	      	static final int CSIDL_COMMON_APPDATA = 0x0023;
	      	static final int SHGFP_TYPE_CURRENT = 0;
	      	static final int S_OK = 0;

	      	static Shell32 INSTANCE = (Shell32) Native.loadLibrary("shell32", Shell32.class, W32APIOptions.UNICODE_OPTIONS);

	      	/**         
	      	 * @see <a href="http://msdn.microsoft.com/en-us/library/bb762181(VS.85).aspx">SHGetFolderPath</a>
	      	 */
	      	public int SHGetFolderPath(HWND hwndOwner, int nFolder, HANDLE hToken, int dwFlags, char[] pszPath);

  	}
}