1 /* Licensed to the Apache Software Foundation (ASF) under one or more 2 * contributor license agreements. See the NOTICE file distributed with 3 * this work for additional information regarding copyright ownership. 4 * The ASF licenses this file to You under the Apache License, Version 2.0 5 * (the "License"); you may not use this file except in compliance with 6 * the License. You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package java.nio; 18 19 import java.io.FileDescriptor; 20 import java.nio.channels.FileChannel; 21 22 /** 23 * @hide internal use only 24 */ 25 public final class NioUtils { NioUtils()26 private NioUtils() { 27 } 28 freeDirectBuffer(ByteBuffer buffer)29 public static void freeDirectBuffer(ByteBuffer buffer) { 30 if (buffer == null) { 31 return; 32 } 33 ((DirectByteBuffer) buffer).free(); 34 } 35 36 /** 37 * Returns the int file descriptor from within the given FileChannel 'fc'. 38 */ getFD(FileChannel fc)39 public static FileDescriptor getFD(FileChannel fc) { 40 return ((FileChannelImpl) fc).getFD(); 41 } 42 43 /** 44 * Helps bridge between io and nio. 45 */ newFileChannel(Object stream, FileDescriptor fd, int mode)46 public static FileChannel newFileChannel(Object stream, FileDescriptor fd, int mode) { 47 return new FileChannelImpl(stream, fd, mode); 48 } 49 50 /** 51 * Exposes the array backing a non-direct ByteBuffer, even if the ByteBuffer is read-only. 52 * Normally, attempting to access the array backing a read-only buffer throws. 53 */ unsafeArray(ByteBuffer b)54 public static byte[] unsafeArray(ByteBuffer b) { 55 return ((ByteArrayBuffer) b).backingArray; 56 } 57 58 /** 59 * Exposes the array offset for the array backing a non-direct ByteBuffer, 60 * even if the ByteBuffer is read-only. 61 */ unsafeArrayOffset(ByteBuffer b)62 public static int unsafeArrayOffset(ByteBuffer b) { 63 return ((ByteArrayBuffer) b).arrayOffset; 64 } 65 } 66