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 }