- /*
- * Copyright 2000-2004 The Apache Software Foundation
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- */
-
- package org.apache.tools.ant.types.selectors;
-
- import org.apache.tools.ant.util.FileUtils;
- import org.apache.tools.ant.BuildException;
-
- import java.io.File;
- import java.io.IOException;
-
- /**
- * This selector selects files against a mapped set of target files, selecting
- * all those files which are different. A byte-by-byte comparision is performed
- * on equal length files; files with different lengths are deemed different
- * automatically; files with identical timestamps are viewed as matching by
- * default, unless you specify otherwise.
- * <p>
- * This is a useful selector to work with programs and tasks that don't handle
- * dependency checking properly; Even if a predecessor task always creates its
- * output files, followup tasks can be driven off copies made with a different
- * selector, so their dependencies are driven on the absolute state of the
- * files, not a timestamp.
- * <p>
- * Clearly, however, bulk file comparisons is inefficient; anything that can
- * use timestamps is to be preferred. If this selector must be used, use it
- * over as few files as possible, perhaps following it with an <uptodate;>
- * to keep the descendent routines conditional.
- *
- */
- public class DifferentSelector extends MappingSelector {
-
- private FileUtils fileUtils = FileUtils.newFileUtils();
-
- private boolean ignoreFileTimes = true;
-
-
- /**
- * This flag tells the selector to ignore file times in the comparison
- * @param ignoreFileTimes if true ignore file times
- */
- public void setIgnoreFileTimes(boolean ignoreFileTimes) {
- this.ignoreFileTimes = ignoreFileTimes;
- }
-
- /**
- * this test is our selection test that compared the file with the destfile
- * @param srcfile the source file
- * @param destfile the destination file
- * @return true if the files are different
- */
- protected boolean selectionTest(File srcfile, File destfile) {
-
- //if either of them is missing, they are different
- if (srcfile.exists() != destfile.exists()) {
- return true;
- }
-
- if (srcfile.length() != destfile.length()) {
- // different size =>different files
- return true;
- }
-
- if (!ignoreFileTimes) {
- //same date if dest timestamp is within granularity of the srcfile
- boolean sameDate;
- sameDate = destfile.lastModified() >= srcfile.lastModified() - granularity
- && destfile.lastModified() <= srcfile.lastModified() + granularity;
-
- // different dates => different files
- if (!sameDate) {
- return true;
- }
- }
-
- //here do a bulk comparison
- try {
- return !fileUtils.contentEquals(srcfile, destfile);
- } catch (IOException e) {
- throw new BuildException("while comparing " + srcfile + " and "
- + destfile, e);
- }
- }
- }