singleton java 8 date formatters

5 files changed, 132 insertions, 19 deletions

diff --git a/juick-core/src/main/java/com/juick/util/DateFormatter.java b/juick-core/src/main/java/com/juick/util/DateFormatter.java
new file mode 100644
index 00000000..34585c63
--- /dev/null
+++ b/juick-core/src/main/java/com/juick/util/DateFormatter.java
@@ -0,0 +1,38 @@
+package com.juick.util;
+
+import org.apache.commons.lang3.StringUtils;
+
+import java.time.LocalDateTime;
+import java.time.ZoneOffset;
+import java.time.format.DateTimeFormatter;
+import java.util.Date;
+
+/**
+ * Created by aalexeev on 12/7/16.
+ */
+public class DateFormatter {
+    private final DateTimeFormatter formatter;
+
+    DateFormatter(String pattern) {
+        formatter = DateTimeFormatter.ofPattern(pattern);
+    }
+
+    public String format(final Date date) {
+        if (date == null)
+            return null;
+
+        LocalDateTime ldt = LocalDateTime.ofInstant(date.toInstant(), ZoneOffset.UTC);
+
+        return ldt.format(formatter);
+    }
+
+
+    public Date parse(final String v) {
+        if (StringUtils.isBlank(v))
+            return null;
+
+        LocalDateTime ldt = LocalDateTime.parse(v, formatter);
+
+        return Date.from(ldt.toInstant(ZoneOffset.UTC));
+    }
+}
diff --git a/juick-core/src/main/java/com/juick/util/DateFormattersHolder.java b/juick-core/src/main/java/com/juick/util/DateFormattersHolder.java
new file mode 100644
index 00000000..79414808
--- /dev/null
+++ b/juick-core/src/main/java/com/juick/util/DateFormattersHolder.java
@@ -0,0 +1,43 @@
+package com.juick.util;
+
+/**
+ * Created by aalexeev on 12/7/16.
+ */
+public class DateFormattersHolder {
+
+    private DateFormattersHolder() {
+        throw new IllegalStateException();
+    }
+
+    private static volatile DateFormatter messageFormatter;
+
+    public static DateFormatter getMessageFormatterInstance() {
+        DateFormatter localInstance = messageFormatter;
+
+        if (localInstance == null) {
+            synchronized (DateFormatter.class) {
+                localInstance = messageFormatter;
+
+                if (localInstance == null)
+                    messageFormatter = localInstance = new DateFormatter("yyyy-MM-dd HH:mm:ss");
+            }
+        }
+        return localInstance;
+    }
+
+    private static volatile DateFormatter rssFormatter;
+
+    public static DateFormatter getRssFormatterInstance() {
+        DateFormatter localInstance = rssFormatter;
+
+        if (localInstance == null) {
+            synchronized (DateFormatter.class) {
+                localInstance = rssFormatter;
+
+                if (localInstance == null)
+                    rssFormatter = localInstance = new DateFormatter("EEE, d MMM yyyy HH:mm:ss");
+            }
+        }
+        return localInstance;
+    }
+}
diff --git a/juick-core/src/main/java/com/juick/util/MessageUtils.java b/juick-core/src/main/java/com/juick/util/MessageUtils.java
index 12ae71c1..96d650a8 100644
--- a/juick-core/src/main/java/com/juick/util/MessageUtils.java
+++ b/juick-core/src/main/java/com/juick/util/MessageUtils.java
@@ -24,6 +24,7 @@ public class MessageUtils {
 
         return result;
     }
+
     private static Pattern regexLinks2 = Pattern.compile("((?<=\\s)|(?<=\\A))([\\[\\{]|&lt;)((?:ht|f)tps?://(?:www\\.)?([^\\/\\s\\\"\\)\\!]+)/?(?:[^\\]\\}](?<!&gt;))*)([\\]\\}]|&gt;)");
 
     public static String formatMessageCode(String msg) {
@@ -48,6 +49,7 @@ public class MessageUtils {
 
         return "<pre>" + msg + "</pre>";
     }
+
     public static String formatMessage(String msg) {
         msg = msg.replaceAll("&", "&amp;");
         msg = msg.replaceAll("<", "&lt;");
diff --git a/juick-core/src/main/java/com/juick/xml/adapters/SimpleDateAdapter.java b/juick-core/src/main/java/com/juick/xml/adapters/SimpleDateAdapter.java
index 1093e47a..382db45a 100644
--- a/juick-core/src/main/java/com/juick/xml/adapters/SimpleDateAdapter.java
+++ b/juick-core/src/main/java/com/juick/xml/adapters/SimpleDateAdapter.java
@@ -1,10 +1,9 @@
 package com.juick.xml.adapters;
 
-import java.text.SimpleDateFormat;
-import java.util.Date;
-import java.util.TimeZone;
+import com.juick.util.DateFormattersHolder;
 
 import javax.xml.bind.annotation.adapters.XmlAdapter;
+import java.util.Date;
 
 /**
  * Created by vitalyster on 15.11.2016.
@@ -12,27 +11,13 @@ import javax.xml.bind.annotation.adapters.XmlAdapter;
 
 public class SimpleDateAdapter extends XmlAdapter<String, Date> {
 
-    private final SimpleDateFormat dateFormat;
-    public SimpleDateAdapter() {
-        dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
-        dateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));
-    }
-
     @Override
     public String marshal(Date v) throws Exception {
-        if (v == null) {
-            return null;
-        }
-        synchronized (dateFormat) {
-            return dateFormat.format(v);
-        }
+        return DateFormattersHolder.getMessageFormatterInstance().format(v);
     }
 
     @Override
     public Date unmarshal(String v) throws Exception {
-        synchronized (dateFormat) {
-            return dateFormat.parse(v);
-        }
+        return DateFormattersHolder.getMessageFormatterInstance().parse(v);
     }
-
 }
diff --git a/juick-core/src/test/java/com/juick/FormatterTest.java b/juick-core/src/test/java/com/juick/FormatterTest.java
new file mode 100644
index 00000000..d246c369
--- /dev/null
+++ b/juick-core/src/test/java/com/juick/FormatterTest.java
@@ -0,0 +1,45 @@
+package com.juick;
+
+import com.juick.util.DateFormattersHolder;
+import org.apache.commons.lang3.RandomUtils;
+import org.junit.Test;
+
+import java.util.Calendar;
+import java.util.Date;
+import java.util.GregorianCalendar;
+import java.util.TimeZone;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.*;
+
+/**
+ * Created by aalexeev on 12/7/16.
+ */
+public class FormatterTest {
+
+    @Test
+    public void forAnyDateFormatterShouldReturnNotEmptyString() throws Exception {
+        Date date = new Date();
+
+        assertThat(DateFormattersHolder.getMessageFormatterInstance().format(date), not(isEmptyOrNullString()));
+        assertThat(DateFormattersHolder.getRssFormatterInstance().format(date), not(isEmptyOrNullString()));
+
+        date = new Date(RandomUtils.nextLong(1, Long.MAX_VALUE / 10000));
+
+        assertThat(DateFormattersHolder.getMessageFormatterInstance().format(date), not(isEmptyOrNullString()));
+        assertThat(DateFormattersHolder.getRssFormatterInstance().format(date), not(isEmptyOrNullString()));
+    }
+
+    @Test
+    public void forConcreteDateShouldReturnCorrectString() throws Exception {
+        Calendar calendar = GregorianCalendar.getInstance();
+
+        calendar.set(2012, 0, 1, 0, 0, 0);
+        calendar.setTimeZone(TimeZone.getTimeZone("UTC"));
+
+        Date date = calendar.getTime();
+
+        assertThat(DateFormattersHolder.getMessageFormatterInstance().format(date), equalTo("2012-01-01 00:00:00"));
+        assertThat(DateFormattersHolder.getRssFormatterInstance().format(date), equalTo("Sun, 1 Jan 2012 00:00:00"));
+    }
+}