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 */ 017package org.apache.commons.imaging.bytesource; 018 019import java.io.File; 020import java.io.IOException; 021import java.io.InputStream; 022import java.nio.file.Path; 023import java.util.Objects; 024 025import org.apache.commons.imaging.common.BinaryFunctions; 026import org.apache.commons.io.IOUtils; 027import org.apache.commons.io.build.AbstractOrigin; 028import org.apache.commons.io.build.AbstractOrigin.ByteArrayOrigin; 029import org.apache.commons.io.build.AbstractOrigin.FileOrigin; 030import org.apache.commons.io.build.AbstractOrigin.PathOrigin; 031 032public class ByteSource { 033 034 public static ByteSource array(final byte[] array) { 035 return new ByteSource(new ByteArrayOrigin(array), null); 036 } 037 038 public static ByteSource array(final byte[] array, final String name) { 039 return new ByteSource(new ByteArrayOrigin(array), name); 040 } 041 042 public static ByteSource file(final File file) { 043 return new ByteSource(new FileOrigin(file), file.getName()); 044 } 045 046 public static final InputStream getInputStream(final ByteSource byteSource, final long skip) throws IOException { 047 InputStream is = null; 048 boolean succeeded = false; 049 try { 050 is = byteSource.getInputStream(); 051 BinaryFunctions.skipBytes(is, skip); 052 succeeded = true; 053 } finally { 054 if (!succeeded) { 055 IOUtils.close(is); 056 } 057 } 058 return is; 059 } 060 061 public static ByteSource inputStream(final InputStream is, final String name) throws IOException { 062 return new InputStreamByteSource(is, name); 063 } 064 065 public static ByteSource path(final Path file) { 066 return new ByteSource(new PathOrigin(file), Objects.toString(file.getFileName(), null)); 067 } 068 069 private final String fileName; 070 private final AbstractOrigin<?, ?> origin; 071 072 ByteSource(final AbstractOrigin<?, ?> origin, final String fileName) { 073 this.origin = Objects.requireNonNull(origin, "origin"); 074 this.fileName = fileName; // may be null 075 } 076 077 public byte[] getByteArray(final long position, final int length) throws IOException { 078 return origin.getByteArray(position, length); 079 } 080 081 public final String getFileName() { 082 return fileName; 083 } 084 085 public InputStream getInputStream() throws IOException { 086 return origin.getInputStream(); 087 } 088 089 /** 090 * This operation can be VERY expensive; for InputStream byte sources, the entire stream must be drained to determine its length. 091 * 092 * @return the byte source length 093 * @throws IOException if it fails to read the byte source data 094 */ 095 public long size() throws IOException { 096 return origin.size(); 097 } 098 099 @Override 100 public String toString() { 101 return getClass().getSimpleName() + "[" + getFileName() + "]"; 102 } 103 104}