/hg/icedtea-web: Added MD5SumWatcher utility class
aazores at icedtea.classpath.org
aazores at icedtea.classpath.org
Mon Mar 10 19:40:07 UTC 2014
changeset f6336bc81da8 in /hg/icedtea-web
details: http://icedtea.classpath.org/hg/icedtea-web?cmd=changeset;node=f6336bc81da8
author: Andrew Azores <aazores at redhat.com>
date: Mon Mar 10 15:39:56 2014 -0400
Added MD5SumWatcher utility class
Added MD5SumWatcher utility class to detect when a file's contents have been
changed on disk.
* netx/net/sourceforge/jnlp/util/FileUtils.java: (getFileMD5Sum) new
function
* netx/net/sourceforge/jnlp/util/MD5SumWatcher.java: new class
* tests/netx/unit/net/sourceforge/jnlp/util/MD5SumWatcherTest.java: new
tests for MD5SumWatcher
diffstat:
ChangeLog | 10 +
netx/net/sourceforge/jnlp/util/FileUtils.java | 27 ++
netx/net/sourceforge/jnlp/util/MD5SumWatcher.java | 104 +++++++++
tests/netx/unit/net/sourceforge/jnlp/util/MD5SumWatcherTest.java | 113 ++++++++++
4 files changed, 254 insertions(+), 0 deletions(-)
diffs (286 lines):
diff -r 483ab446ea4c -r f6336bc81da8 ChangeLog
--- a/ChangeLog Mon Mar 10 12:29:47 2014 -0400
+++ b/ChangeLog Mon Mar 10 15:39:56 2014 -0400
@@ -1,3 +1,13 @@
+2014-03-10 Andrew Azores <aazores at redhat.com>
+
+ Added MD5SumWatcher utility class to detect when a file's contents have been
+ changed on disk.
+ * netx/net/sourceforge/jnlp/util/FileUtils.java: (getFileMD5Sum) new
+ function
+ * netx/net/sourceforge/jnlp/util/MD5SumWatcher.java: new class
+ * tests/netx/unit/net/sourceforge/jnlp/util/MD5SumWatcherTest.java: new
+ tests for MD5SumWatcher
+
2014-03-10 Andrew Azores <aazores at redhat.com>
* tests/netx/unit/net/sourceforge/jnlp/security/policyeditor/PolicyEditorPermissionsTest.java:
diff -r 483ab446ea4c -r f6336bc81da8 netx/net/sourceforge/jnlp/util/FileUtils.java
--- a/netx/net/sourceforge/jnlp/util/FileUtils.java Mon Mar 10 12:29:47 2014 -0400
+++ b/netx/net/sourceforge/jnlp/util/FileUtils.java Mon Mar 10 15:39:56 2014 -0400
@@ -30,8 +30,12 @@
import java.io.OutputStreamWriter;
import java.io.RandomAccessFile;
import java.io.Writer;
+import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import java.nio.channels.FileLock;
+import java.security.DigestInputStream;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
import java.util.ArrayList;
import java.util.List;
@@ -587,4 +591,27 @@
public static String loadFileAsString(File f, String encoding) throws IOException {
return getContentOfStream(new FileInputStream(f), encoding);
}
+
+ public static byte[] getFileMD5Sum(final File file, final String algorithm) throws NoSuchAlgorithmException,
+ FileNotFoundException, IOException {
+ final MessageDigest md5;
+ InputStream is = null;
+ DigestInputStream dis = null;
+ try {
+ md5 = MessageDigest.getInstance(algorithm);
+ is = new FileInputStream(file);
+ dis = new DigestInputStream(is, md5);
+
+ md5.update(getContentOfStream(dis).getBytes());
+ } finally {
+ if (is != null) {
+ is.close();
+ }
+ if (dis != null) {
+ dis.close();
+ }
+ }
+
+ return md5.digest();
+ }
}
diff -r 483ab446ea4c -r f6336bc81da8 netx/net/sourceforge/jnlp/util/MD5SumWatcher.java
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/netx/net/sourceforge/jnlp/util/MD5SumWatcher.java Mon Mar 10 15:39:56 2014 -0400
@@ -0,0 +1,104 @@
+/*Copyright (C) 2014 Red Hat, Inc.
+
+This file is part of IcedTea.
+
+IcedTea is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License as published by
+the Free Software Foundation, version 2.
+
+IcedTea is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with IcedTea; see the file COPYING. If not, write to
+the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library. Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module. An independent module is a module which is not derived from
+or based on this library. If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so. If you do not wish to do so, delete this
+exception statement from your version.
+ */
+
+package net.sourceforge.jnlp.util;
+
+import static net.sourceforge.jnlp.runtime.Translator.R;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.security.NoSuchAlgorithmException;
+import java.util.Arrays;
+
+import javax.swing.JFrame;
+import javax.swing.JOptionPane;
+
+import net.sourceforge.jnlp.util.logging.OutputController;
+
+public class MD5SumWatcher {
+
+ private final File watchedFile;
+ private byte[] md5sum;
+
+ /**
+ * Create a new MD5SumWatcher instance
+ * @param watchedFile the file to watch
+ */
+ public MD5SumWatcher(final File watchedFile) {
+ this.watchedFile = watchedFile;
+ try {
+ this.md5sum = getSum();
+ } catch (final IOException ioe) {
+ OutputController.getLogger().log(ioe);
+ this.md5sum = null;
+ }
+ }
+
+ /**
+ * Get the current MD5 sum of the watched file
+ * @return a byte array of the MD5 sum
+ * @throws FileNotFoundException if the watched file does not exist
+ * @throws IOException if the file cannot be read
+ */
+ public byte[] getSum() throws FileNotFoundException, IOException {
+ update();
+ return md5sum;
+ }
+
+ /**
+ * Detect if the file's MD5 has changed and track its new sum if so
+ * @return if the file's MD5 has changed since the last update
+ * @throws FileNotFoundException if the watched file does not exist
+ * @throws IOException if the file cannot be read
+ */
+ public boolean update() throws FileNotFoundException, IOException {
+ byte[] newSum;
+ try {
+ newSum = FileUtils.getFileMD5Sum(watchedFile, "MD5");
+ } catch (final NoSuchAlgorithmException e) {
+ // There definitely should be an MD5 algorithm, but if not, all we can do is fail.
+ // This really, really is not expected to happen, so rethrow as RuntimeException
+ // to avoid having to check for NoSuchAlgorithmExceptions all the time
+ OutputController.getLogger().log(e);
+ throw new RuntimeException(e);
+ }
+ final boolean changed = !Arrays.equals(newSum, md5sum);
+ md5sum = newSum;
+ return changed;
+ }
+
+}
diff -r 483ab446ea4c -r f6336bc81da8 tests/netx/unit/net/sourceforge/jnlp/util/MD5SumWatcherTest.java
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/netx/unit/net/sourceforge/jnlp/util/MD5SumWatcherTest.java Mon Mar 10 15:39:56 2014 -0400
@@ -0,0 +1,113 @@
+/*Copyright (C) 2014 Red Hat, Inc.
+
+This file is part of IcedTea.
+
+IcedTea is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License as published by
+the Free Software Foundation, version 2.
+
+IcedTea is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with IcedTea; see the file COPYING. If not, write to
+the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library. Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module. An independent module is a module which is not derived from
+or based on this library. If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so. If you do not wish to do so, delete this
+exception statement from your version.
+ */
+
+package net.sourceforge.jnlp.util;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.util.Arrays;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+public class MD5SumWatcherTest {
+
+ private File file;
+ private MD5SumWatcher watcher;
+
+ @Before
+ public void createNewFile() throws Exception {
+ file = File.createTempFile("md5sumwatchertest", "tmp");
+ file.deleteOnExit();
+ watcher = new MD5SumWatcher(file);
+ }
+
+ @After
+ public void deleteTempFile() throws Exception {
+ if (file.exists()) {
+ file.delete();
+ }
+ }
+
+ @Test
+ public void testNonExistentFile() {
+ file.delete();
+ file.mkdirs();
+ watcher = new MD5SumWatcher(file);
+ boolean gotException = false;
+ try {
+ watcher.update();
+ } catch (final Exception e) {
+ gotException = true;
+ assertTrue("Should have received FileNotFoundException", e instanceof FileNotFoundException);
+ }
+ assertTrue("Should have received FileNotFoundException", gotException);
+ }
+
+ @Test
+ public void testNoFileChangeGivesSameMd5() throws Exception {
+ byte[] sum = watcher.getSum();
+ byte[] sum2 = watcher.getSum();
+ assertTrue("MD5 sums should be the same. first: " + Arrays.toString(sum) + ", second: " + Arrays.toString(sum2),
+ Arrays.equals(sum, sum2));
+ }
+
+ @Test
+ public void testSavingToFileChangesMd5() throws Exception {
+ byte[] original = watcher.getSum();
+ FileUtils.saveFile("some test content\n", file);
+ byte[] changed = watcher.getSum();
+ assertFalse("MD5 sum should have changed, but was constant as " + Arrays.toString(original),
+ Arrays.equals(original, changed));
+ }
+
+ @Test
+ public void testUnchangedContentUpdate() throws Exception {
+ assertFalse("update() should return false", watcher.update());
+ }
+
+ @Test
+ public void testChangedContentUpdate() throws Exception {
+ FileUtils.saveFile("some test content\n", file);
+ final boolean changed = watcher.update();
+ assertTrue("update() should return true", changed);
+ }
+
+}
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