001/* 002 * Copyright 2012-2018 the original author or authors. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * http://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package org.springframework.boot.loader.data; 018 019import java.io.EOFException; 020import java.io.IOException; 021import java.io.InputStream; 022 023/** 024 * Interface that provides read-only random access to some underlying data. 025 * Implementations must allow concurrent reads in a thread-safe manner. 026 * 027 * @author Phillip Webb 028 */ 029public interface RandomAccessData { 030 031 /** 032 * Returns an {@link InputStream} that can be used to read the underlying data. The 033 * caller is responsible close the underlying stream. 034 * @return a new input stream that can be used to read the underlying data. 035 * @throws IOException if the stream cannot be opened 036 */ 037 InputStream getInputStream() throws IOException; 038 039 /** 040 * Returns a new {@link RandomAccessData} for a specific subsection of this data. 041 * @param offset the offset of the subsection 042 * @param length the length of the subsection 043 * @return the subsection data 044 */ 045 RandomAccessData getSubsection(long offset, long length); 046 047 /** 048 * Reads all the data and returns it as a byte array. 049 * @return the data 050 * @throws IOException if the data cannot be read 051 */ 052 byte[] read() throws IOException; 053 054 /** 055 * Reads the {@code length} bytes of data starting at the given {@code offset}. 056 * @param offset the offset from which data should be read 057 * @param length the number of bytes to be read 058 * @return the data 059 * @throws IOException if the data cannot be read 060 * @throws IndexOutOfBoundsException if offset is beyond the end of the file or 061 * subsection 062 * @throws EOFException if offset plus length is greater than the length of the file 063 * or subsection 064 */ 065 byte[] read(long offset, long length) throws IOException; 066 067 /** 068 * Returns the size of the data. 069 * @return the size 070 */ 071 long getSize(); 072 073}