| 1 | /* |
| 2 | * Copyright 2006-2007 the original author or authors. |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * 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 org.springframework.batch.item.util; |
| 18 | |
| 19 | import java.io.File; |
| 20 | import java.io.IOException; |
| 21 | |
| 22 | import org.springframework.batch.item.ItemStreamException; |
| 23 | import org.springframework.util.Assert; |
| 24 | |
| 25 | /** |
| 26 | * Utility methods for files used in batch processing. |
| 27 | * |
| 28 | * @author Peter Zozom |
| 29 | */ |
| 30 | public final class FileUtils { |
| 31 | |
| 32 | // forbids instantiation |
| 33 | private FileUtils() { |
| 34 | } |
| 35 | |
| 36 | /** |
| 37 | * Set up output file for batch processing. This method implements common logic for handling output files when |
| 38 | * starting or restarting file I/O. When starting output file processing, creates/overwrites new file. When |
| 39 | * restarting output file processing, checks whether file is writable. |
| 40 | * |
| 41 | * @param file file to be set up |
| 42 | * @param restarted true signals that we are restarting output file processing |
| 43 | * @param append true signals input file may already exist (but doesn't have to) |
| 44 | * @param overwriteOutputFile If set to true, output file will be overwritten (this flag is ignored when processing |
| 45 | * is restart) |
| 46 | * |
| 47 | * @throws IllegalArgumentException when file is null |
| 48 | * @throws ItemStreamException when starting output file processing, file exists and flag "overwriteOutputFile" is |
| 49 | * set to false |
| 50 | * @throws ItemStreamException when unable to create file or file is not writable |
| 51 | */ |
| 52 | public static void setUpOutputFile(File file, boolean restarted, boolean append, boolean overwriteOutputFile) { |
| 53 | |
| 54 | Assert.notNull(file); |
| 55 | |
| 56 | try { |
| 57 | if (!restarted) { |
| 58 | if (!append) { |
| 59 | if (file.exists()) { |
| 60 | if (!overwriteOutputFile) { |
| 61 | throw new ItemStreamException("File already exists: [" + file.getAbsolutePath() + "]"); |
| 62 | } |
| 63 | if (!file.delete()) { |
| 64 | throw new IOException("Could not delete file: " + file); |
| 65 | } |
| 66 | } |
| 67 | |
| 68 | if (file.getParent() != null) { |
| 69 | new File(file.getParent()).mkdirs(); |
| 70 | } |
| 71 | if (!createNewFile(file)) { |
| 72 | throw new ItemStreamException("Output file was not created: [" + file.getAbsolutePath() + "]"); |
| 73 | } |
| 74 | } |
| 75 | else { |
| 76 | if (!file.exists()) { |
| 77 | if (!createNewFile(file)) { |
| 78 | throw new ItemStreamException("Output file was not created: [" + file.getAbsolutePath() |
| 79 | + "]"); |
| 80 | } |
| 81 | } |
| 82 | } |
| 83 | } |
| 84 | } |
| 85 | catch (IOException ioe) { |
| 86 | throw new ItemStreamException("Unable to create file: [" + file.getAbsolutePath() + "]", ioe); |
| 87 | } |
| 88 | |
| 89 | if (!file.canWrite()) { |
| 90 | throw new ItemStreamException("File is not writable: [" + file.getAbsolutePath() + "]"); |
| 91 | } |
| 92 | } |
| 93 | |
| 94 | /** |
| 95 | * @deprecated use the version with explicit append parameter instead. Here append=false is assumed. |
| 96 | */ |
| 97 | public static void setUpOutputFile(File file, boolean restarted, boolean overwriteOutputFile) { |
| 98 | setUpOutputFile(file, restarted, false, overwriteOutputFile); |
| 99 | } |
| 100 | |
| 101 | /** |
| 102 | * Create a new file if it doesn't already exist. |
| 103 | * |
| 104 | * @param file the file to create on the filesystem |
| 105 | */ |
| 106 | public static boolean createNewFile(File file) throws IOException { |
| 107 | |
| 108 | if (file.exists()) { |
| 109 | return false; |
| 110 | } |
| 111 | |
| 112 | try { |
| 113 | return file.createNewFile() && file.exists(); |
| 114 | } |
| 115 | catch (IOException e) { |
| 116 | // On some filesystems you can get an exception here even though the |
| 117 | // files was successfully created |
| 118 | if (file.exists()) { |
| 119 | return true; |
| 120 | } |
| 121 | else { |
| 122 | throw e; |
| 123 | } |
| 124 | } |
| 125 | |
| 126 | } |
| 127 | |
| 128 | } |