Fixed unsafe conccurent access to generic SimpleDateFormat instances

SimpleDateFormat must not be used by concurrent threads without
synchronization for parsing or formating dates as it is not thread-safe
(internally holds a calendar instance that is not synchronized).

Prefer now DateTimeFormatter when possible as it is thread-safe without
concurrent access performance bottleneck (does not internally use
synchronization locks).

1 files changed, 87 insertions, 0 deletions

diff --git a/test/java/net/yacy/cora/date/GenericFormatterTest.java b/test/java/net/yacy/cora/date/GenericFormatterTest.java
new file mode 100644
index 000000000..6ddbd00dc
--- /dev/null
+++ b/test/java/net/yacy/cora/date/GenericFormatterTest.java
@@ -0,0 +1,87 @@
+// GenericFormatterTest.java
+// Copyright 2018 by luccioman; https://github.com/luccioman
+//
+// This is a part of YaCy, a peer-to-peer based web search engine
+//
+// LICENSE
+//
+// This program 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; either version 2 of the License, or
+// (at your option) any later version.
+//
+// This program 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 this program; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+package net.yacy.cora.date;
+
+import java.text.SimpleDateFormat;
+import java.time.Instant;
+import java.util.Date;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * Unit tests for the {@link GenericFormatter} class.
+ */
+public class GenericFormatterTest {
+
+	/**
+	 * Check that the date patterns are properly written : no error should occur
+	 * when using them for formatting and parsing.
+	 */
+	@Test
+	public void testFormats() {
+		final Instant time = Instant.parse("2018-06-28T10:49:35.726Z");
+
+		String formatted = GenericFormatter.FORMAT_SHORT_DAY.format(time);
+		System.out.println("GenericFormatter.FORMAT_SHORT_DAY : " + formatted);
+		SimpleDateFormat oldApiFormat = GenericFormatter.newShortDayFormat();
+		Assert.assertEquals(oldApiFormat.format(Date.from(time)), formatted);
+		GenericFormatter.FORMAT_SHORT_DAY.parse("20180628");
+
+		formatted = GenericFormatter.FORMAT_SHORT_MINUTE.format(time);
+		System.out.println("GenericFormatter.FORMAT_SHORT_MINUTE : " + formatted);
+		oldApiFormat = GenericFormatter.newShortMinuteFormat();
+		Assert.assertEquals(oldApiFormat.format(Date.from(time)), formatted);
+		GenericFormatter.FORMAT_SHORT_MINUTE.parse("201806281407");
+
+		formatted = GenericFormatter.FORMAT_SHORT_SECOND.format(time);
+		System.out.println("GenericFormatter.FORMAT_SHORT_SECOND : " + formatted);
+		oldApiFormat = GenericFormatter.newShortSecondFormat();
+		Assert.assertEquals(oldApiFormat.format(Date.from(time)), formatted);
+		GenericFormatter.FORMAT_SHORT_SECOND.parse("20180628140713");
+
+		formatted = GenericFormatter.FORMAT_SHORT_MILSEC.format(time);
+		System.out.println("GenericFormatter.FORMAT_SHORT_MILSEC : " + formatted);
+		oldApiFormat = GenericFormatter.newShortMilsecFormat();
+		Assert.assertEquals(oldApiFormat.format(Date.from(time)), formatted);
+		GenericFormatter.FORMAT_SHORT_MILSEC.parse("20180628140713921");
+
+		formatted = GenericFormatter.FORMAT_RFC1123_SHORT.format(time);
+		System.out.println("GenericFormatter.FORMAT_RFC1123_SHORT : " + formatted);
+		oldApiFormat = GenericFormatter.newRfc1123ShortFormat();
+		Assert.assertEquals(oldApiFormat.format(Date.from(time)), formatted);
+		GenericFormatter.FORMAT_RFC1123_SHORT.parse("Thu, 28 Jun 2018");
+
+		formatted = GenericFormatter.FORMAT_ANSIC.format(time);
+		System.out.println("GenericFormatter.FORMAT_ANSIC : " + formatted);
+		oldApiFormat = GenericFormatter.newAnsicFormat();
+		Assert.assertEquals(oldApiFormat.format(Date.from(time)), formatted);
+		GenericFormatter.FORMAT_ANSIC.parse("Thu Jun 28 15:48:17 2018");
+
+		formatted = GenericFormatter.FORMAT_SIMPLE.format(time);
+		System.out.println("GenericFormatter.FORMAT_SIMPLE : " + formatted);
+		oldApiFormat = GenericFormatter.newSimpleDateFormat();
+		Assert.assertEquals(oldApiFormat.format(Date.from(time)), formatted);
+		GenericFormatter.FORMAT_SIMPLE.parse("2018/06/28 15:27:45");
+	}
+
+}