Allow users of the api to pass in a custom formatter to the LocalDateTimeSerializer/Deserializer.

Author: iainCFX

src/main/java/com/fasterxml/jackson/datatype/jsr310/deser/LocalDateTimeDeserializer.java

@@ -42,13 +42,13 @@ private LocalDateTimeDeserializer() {
         this(DateTimeFormatter.ISO_LOCAL_DATE_TIME);
     }
 
-    protected LocalDateTimeDeserializer(DateTimeFormatter dtf) {
-        super(LocalDateTime.class, dtf);
+    public LocalDateTimeDeserializer(DateTimeFormatter formatter) {
+        super(LocalDateTime.class, formatter);
     }
 
     @Override
-    protected JsonDeserializer<LocalDateTime> withDateFormat(DateTimeFormatter dtf) {
-        return new LocalDateTimeDeserializer(dtf);
+    protected JsonDeserializer<LocalDateTime> withDateFormat(DateTimeFormatter formatter) {
+        return new LocalDateTimeDeserializer(formatter);
     }
 
     @Override

src/main/java/com/fasterxml/jackson/datatype/jsr310/ser/LocalDateTimeSerializer.java

@@ -38,17 +38,20 @@ public class LocalDateTimeSerializer extends JSR310FormattedSerializerBase<Local
     public static final LocalDateTimeSerializer INSTANCE = new LocalDateTimeSerializer();
 
     protected LocalDateTimeSerializer() {
-        super(LocalDateTime.class);
+        this(null);
     }
 
-    private LocalDateTimeSerializer(LocalDateTimeSerializer base,
-            Boolean useTimestamp, DateTimeFormatter dtf) {
-        super(base, useTimestamp, dtf);
+    public LocalDateTimeSerializer(DateTimeFormatter formatter) {
+        super(LocalDateTime.class, formatter);
+    }
+
+    private LocalDateTimeSerializer(LocalDateTimeSerializer base, Boolean useTimestamp, DateTimeFormatter formatter) {
+        super(base, useTimestamp, formatter);
     }
 
     @Override
-    protected JSR310FormattedSerializerBase<LocalDateTime> withFormat(Boolean useTimestamp, DateTimeFormatter dtf) {
-        return new LocalDateTimeSerializer(this, useTimestamp, dtf);
+    protected JSR310FormattedSerializerBase<LocalDateTime> withFormat(Boolean useTimestamp, DateTimeFormatter formatter) {
+        return new LocalDateTimeSerializer(this, useTimestamp, formatter);
     }
 
     @Override

src/test/java/com/fasterxml/jackson/datatype/jsr310/TestLocalDateTimeSerializationWithCustomFormatter.java

@@ -0,0 +1,62 @@
+package com.fasterxml.jackson.datatype.jsr310;
+
+import static org.hamcrest.core.IsEqual.equalTo;
+import static org.junit.Assert.assertThat;
+import static org.junit.internal.matchers.StringContains.containsString;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.module.SimpleModule;
+import com.fasterxml.jackson.datatype.jsr310.deser.LocalDateTimeDeserializer;
+import com.fasterxml.jackson.datatype.jsr310.ser.LocalDateTimeSerializer;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameters;
+
+import java.text.SimpleDateFormat;
+import java.time.LocalDate;
+import java.time.LocalDateTime;
+import java.time.ZoneId;
+import java.time.format.DateTimeFormatter;
+import java.time.format.DateTimeFormatterBuilder;
+import java.util.ArrayList;
+import java.util.Collection;
+
+@RunWith(Parameterized.class)
+public class TestLocalDateTimeSerializationWithCustomFormatter {
+    private final DateTimeFormatter formatter;
+
+    public TestLocalDateTimeSerializationWithCustomFormatter(DateTimeFormatter formatter) {
+        this.formatter = formatter;
+    }
+
+    @Test
+    public void testSerialization() throws Exception {
+        LocalDateTime dateTime = LocalDateTime.now();
+        assertThat("Failed to serialize with " + formatter, serializeWith(dateTime, formatter), containsString(dateTime.format(formatter)));
+    }
+
+    private String serializeWith(LocalDateTime dateTime, DateTimeFormatter formatter) throws Exception {
+        ObjectMapper mapper = new ObjectMapper().registerModule(new SimpleModule().addSerializer(new LocalDateTimeSerializer(formatter)));
+        return mapper.writeValueAsString(dateTime);
+    }
+
+    @Test
+    public void testDeserialization() throws Exception {
+        LocalDateTime dateTime = LocalDateTime.now();
+        assertThat(deserializeWith(dateTime.format(formatter), formatter), equalTo(dateTime));
+    }
+
+    private LocalDateTime deserializeWith(String json, DateTimeFormatter formatter) throws Exception {
+        ObjectMapper mapper = new ObjectMapper().registerModule(new SimpleModule().addDeserializer(LocalDateTime.class, new LocalDateTimeDeserializer(formatter)));
+        return mapper.readValue("\"" + json + "\"", LocalDateTime.class);
+    }
+
+    @Parameters
+    public static Collection<Object[]> customFormatters() {
+        Collection<Object[]> formatters = new ArrayList<>();
+        formatters.add(new Object[]{DateTimeFormatter.ISO_DATE_TIME});
+        formatters.add(new Object[]{DateTimeFormatter.ISO_LOCAL_DATE_TIME});
+        return formatters;
+    }
+}