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package sun.nio.fs;

import java.nio.file.*;
import java.io.IOException;

File type detector that does lookup of file extension using Windows Registry.
/** * File type detector that does lookup of file extension using Windows Registry. */
public class RegistryFileTypeDetector extends AbstractFileTypeDetector { public RegistryFileTypeDetector() { super(); } @Override public String implProbeContentType(Path file) throws IOException { if (!(file instanceof Path)) return null; // get file extension Path name = file.getFileName(); if (name == null) return null; String filename = name.toString(); int dot = filename.lastIndexOf('.'); if ((dot < 0) || (dot == (filename.length()-1))) return null; // query HKEY_CLASSES_ROOT\<ext> String key = filename.substring(dot); NativeBuffer keyBuffer = null; NativeBuffer nameBuffer = null; try { keyBuffer = WindowsNativeDispatcher.asNativeBuffer(key); nameBuffer = WindowsNativeDispatcher.asNativeBuffer("Content Type"); return queryStringValue(keyBuffer.address(), nameBuffer.address()); } catch (WindowsException we) { we.rethrowAsIOException(file.toString()); return null; // keep compiler happy } finally { nameBuffer.release(); keyBuffer.release(); } } private static native String queryStringValue(long subKey, long name); static { // nio.dll has dependency on net.dll jdk.internal.loader.BootLoader.loadLibrary("net"); jdk.internal.loader.BootLoader.loadLibrary("nio"); } }