001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 018package org.apache.commons.io; 019 020import java.io.IOException; 021import java.io.RandomAccessFile; 022 023/** 024 * Works on RandomAccessFile. 025 * 026 * @since 2.13.0 027 */ 028public class RandomAccessFiles { 029 030 /** 031 * Reads a byte array starting at "position" for "length" bytes. 032 * 033 * @param input The source RandomAccessFile. 034 * @param position The offset position, measured in bytes from the beginning of the file, at which to set the file pointer. 035 * @param length How many bytes to read. 036 * @return a new byte array. 037 * @throws IOException If the first byte cannot be read for any reason other than end of file, or if the random access file has been closed, or if some 038 * other I/O error occurs. 039 */ 040 public static byte[] read(final RandomAccessFile input, final long position, final int length) throws IOException { 041 input.seek(position); 042 return IOUtils.toByteArray(input::read, length); 043 } 044 045}