Add Kotlin extension functions support

gson-javatime-serialisers.iml

@@ -1,6 +1,27 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <module org.jetbrains.idea.maven.project.MavenProjectsManager.isMavenModule="true" type="JAVA_MODULE" version="4">
-  <component name="NewModuleRootManager" LANGUAGE_LEVEL="JDK_1_8" inherit-compiler-output="false">
+  <component name="FacetManager">
+    <facet type="kotlin-language" name="Kotlin">
+      <configuration version="3" platform="JVM 1.8" useProjectSettings="false">
+        <compilerSettings />
+        <compilerArguments>
+          <option name="jvmTarget" value="1.8" />
+          <option name="languageVersion" value="1.3" />
+          <option name="apiVersion" value="1.3" />
+          <option name="pluginOptions">
+            <array />
+          </option>
+          <option name="pluginClasspaths">
+            <array />
+          </option>
+          <option name="errors">
+            <ArgumentParseErrors />
+          </option>
+        </compilerArguments>
+      </configuration>
+    </facet>
+  </component>
+  <component name="NewModuleRootManager" LANGUAGE_LEVEL="JDK_1_8">
     <output url="file://$MODULE_DIR$/target/classes" />
     <output-test url="file://$MODULE_DIR$/target/test-classes" />
     <content url="file://$MODULE_DIR$">
@@ -14,5 +35,12 @@
     <orderEntry type="library" scope="TEST" name="Maven: org.hamcrest:hamcrest-core:1.3" level="project" />
     <orderEntry type="library" scope="TEST" name="Maven: org.hamcrest:hamcrest-all:1.3" level="project" />
     <orderEntry type="library" name="Maven: com.google.code.gson:gson:2.3.1" level="project" />
+    <orderEntry type="library" name="Maven: org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.3.21" level="project" />
+    <orderEntry type="library" name="Maven: org.jetbrains.kotlin:kotlin-stdlib:1.3.21" level="project" />
+    <orderEntry type="library" name="Maven: org.jetbrains.kotlin:kotlin-stdlib-common:1.3.21" level="project" />
+    <orderEntry type="library" name="Maven: org.jetbrains:annotations:13.0" level="project" />
+    <orderEntry type="library" name="Maven: org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.3.21" level="project" />
+    <orderEntry type="library" scope="TEST" name="Maven: org.jetbrains.kotlin:kotlin-test:1.3.21" level="project" />
+    <orderEntry type="library" scope="TEST" name="Maven: org.jetbrains.kotlin:kotlin-test-common:1.3.21" level="project" />
   </component>
 </module>

pom.xml

@@ -59,20 +59,12 @@
 
   <properties>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+      <kotlin.version>1.3.21</kotlin.version>
   </properties>
 
   <build>
     <plugins>
-      <plugin>
-        <groupId>org.apache.maven.plugins</groupId>
-        <artifactId>maven-compiler-plugin</artifactId>
-        <version>3.0</version>
-        <configuration>
-          <source>1.8</source>
-          <target>1.8</target>
-        </configuration>
-      </plugin>
-      <plugin>
+        <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-release-plugin</artifactId>
         <version>2.2.2</version>
@@ -128,6 +120,55 @@
           </archive>
         </configuration>
       </plugin>
+        <plugin>
+            <groupId>org.jetbrains.kotlin</groupId>
+            <artifactId>kotlin-maven-plugin</artifactId>
+            <version>${kotlin.version}</version>
+            <executions>
+                <execution>
+                    <id>compile</id>
+                    <phase>compile</phase>
+                    <goals>
+                        <goal>compile</goal>
+                    </goals>
+                </execution>
+                <execution>
+                    <id>test-compile</id>
+                    <phase>test-compile</phase>
+                    <goals>
+                        <goal>test-compile</goal>
+                    </goals>
+                </execution>
+            </executions>
+            <configuration>
+                <jvmTarget>1.8</jvmTarget>
+            </configuration>
+        </plugin>
+        <plugin>
+          <groupId>org.apache.maven.plugins</groupId>
+          <artifactId>maven-compiler-plugin</artifactId>
+          <version>3.0</version>
+            <executions>
+                <execution>
+                    <id>compile</id>
+                    <phase>compile</phase>
+                    <goals>
+                        <goal>compile</goal>
+                    </goals>
+                </execution>
+                <execution>
+                    <id>testCompile</id>
+                    <phase>test-compile</phase>
+                    <goals>
+                        <goal>testCompile</goal>
+                    </goals>
+                </execution>
+            </executions>
+            <configuration>
+            <source>1.8</source>
+            <target>1.8</target>
+          </configuration>
+        </plugin>
     </plugins>
   </build>
 
@@ -195,6 +236,17 @@
       <artifactId>gson</artifactId>
       <version>2.3.1</version>
     </dependency>
+      <dependency>
+          <groupId>org.jetbrains.kotlin</groupId>
+          <artifactId>kotlin-stdlib-jdk8</artifactId>
+          <version>${kotlin.version}</version>
+      </dependency>
+      <dependency>
+          <groupId>org.jetbrains.kotlin</groupId>
+          <artifactId>kotlin-test</artifactId>
+          <version>${kotlin.version}</version>
+          <scope>test</scope>
+      </dependency>
   </dependencies>
 
 </project>

src/main/java/com/fatboyindustrial/gsonjavatime/KotlinConverters.kt

@@ -0,0 +1,90 @@
+/*
+ * Copyright 2014 Greg Kopff
+ * All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.fatboyindustrial.gsonjavatime
+
+import com.google.gson.GsonBuilder
+import java.time.*
+
+/**
+ * Registers all Java Time converters onto the receiver.
+ *
+ * @see Converters.registerAll
+ */
+fun GsonBuilder.registerAllJavaConverters(): GsonBuilder = this
+    .registerLocalDate()
+    .registerLocalDateTime()
+    .registerLocalTime()
+    .registerOffsetDateTime()
+    .registerOffsetTime()
+    .registerZonedDateTime()
+    .registerInstant()
+
+/**
+ * Registers the [LocalDate] converter onto the receiver.
+ *
+ * @see Converters.registerLocalDate
+ */
+fun GsonBuilder.registerLocalDate(): GsonBuilder = Converters.registerLocalDate(this)
+
+/**
+ * Registers the [LocalDateTime] converter onto the receiver.
+ *
+ * @see Converters.registerLocalDateTime
+ */
+fun GsonBuilder.registerLocalDateTime(): GsonBuilder = Converters.registerLocalDateTime(this)
+
+/**
+ * Registers the [LocalTime] converter onto the receiver.
+ *
+ * @see Converters.registerLocalTime
+ */
+fun GsonBuilder.registerLocalTime(): GsonBuilder = Converters.registerLocalTime(this)
+
+/**
+ * Registers the [OffsetDateTime\] converter onto the receiver.
+ *
+ * @see Converters.registerOffsetDateTime
+ */
+fun GsonBuilder.registerOffsetDateTime(): GsonBuilder = Converters.registerOffsetDateTime(this)
+
+/**
+ * Registers the [OffsetTime] converter onto the receiver.
+ *
+ * @see Converters.registerOffsetTime
+ */
+fun GsonBuilder.registerOffsetTime(): GsonBuilder = Converters.registerOffsetTime(this)
+
+/**
+ * Registers the [ZonedDateTime] converter onto the receiver.
+ *
+ * @see Converters.registerZonedDateTime
+ */
+fun GsonBuilder.registerZonedDateTime(): GsonBuilder = Converters.registerZonedDateTime(this)
+
+/**
+ * Registers the [Instant] converter onto the receiver.
+ *
+ * @see Converters.registerInstant
+ */
+fun GsonBuilder.registerInstant(): GsonBuilder = Converters.registerInstant(this)

src/test/java/com/fatboyindustrial/gsonjavatime/KotlinConvertersTest.kt

@@ -0,0 +1,90 @@
+package com.fatboyindustrial.gsonjavatime
+
+import com.google.gson.GsonBuilder
+import com.google.gson.JsonObject
+import com.google.gson.JsonPrimitive
+import org.hamcrest.Matchers.`is`
+import org.junit.Assert.assertThat
+import org.junit.Test
+import java.time.*
+
+class KotlinConvertersTest {
+
+    /**
+     * Tests that serializing to JSON works.
+     */
+    @Test
+    fun testSerialization() {
+        val gson = GsonBuilder().registerAllJavaConverters().create()
+
+        val container = Container()
+        container.ld = LocalDate.of(1969, 7, 21)
+        container.lt = LocalTime.of(12, 56, 0)
+        container.ldt = LocalDateTime.of(container.ld, container.lt)
+        container.odt = OffsetDateTime.of(container.ld, container.lt, ZoneOffset.ofHours(10))
+        container.ot = OffsetTime.of(container.lt, ZoneOffset.ofHours(10))
+        container.zdt = ZonedDateTime.of(container.ld, container.lt, ZoneId.of("Australia/Brisbane"))
+        container.i = container.odt?.toInstant()
+
+        val jsonString = gson.toJson(container)
+        val json = gson.fromJson(jsonString, JsonObject::class.java).asJsonObject
+
+        assertThat<String>(json.get("ld").asString, `is`<String>("1969-07-21"))
+        assertThat<String>(json.get("lt").asString, `is`<String>("12:56:00"))
+        assertThat<String>(json.get("ldt").asString, `is`<String>("1969-07-21T12:56:00"))
+        assertThat<String>(json.get("odt").asString, `is`<String>("1969-07-21T12:56:00+10:00"))
+        assertThat<String>(json.get("ot").asString, `is`<String>("12:56:00+10:00"))
+        assertThat<String>(json.get("zdt").asString, `is`<String>("1969-07-21T12:56:00+10:00[Australia/Brisbane]"))
+        assertThat<String>(json.get("i").asString, `is`<String>("1969-07-21T02:56:00Z"))
+    }
+
+    /**
+     * Tests that deserializing from JSON works.
+     */
+    @Test
+    fun testDeserialization() {
+        val gson = Converters.registerAll(GsonBuilder()).create()
+
+        val container = Container()
+        container.ld = LocalDate.of(1969, 7, 21)
+        container.lt = LocalTime.of(12, 56, 0)
+        container.ldt = LocalDateTime.of(container.ld, container.lt)
+        container.odt = OffsetDateTime.of(container.ld, container.lt, ZoneOffset.ofHours(10))
+        container.ot = OffsetTime.of(container.lt, ZoneOffset.ofHours(10))
+        container.zdt = ZonedDateTime.of(container.ld, container.lt, ZoneId.of("Australia/Brisbane"))
+        container.i = container.odt?.toInstant()
+
+        val serialized = JsonObject()
+        serialized.add("ld", JsonPrimitive("1969-07-21"))
+        serialized.add("lt", JsonPrimitive("12:56:00"))
+        serialized.add("ldt", JsonPrimitive("1969-07-21T12:56:00"))
+        serialized.add("odt", JsonPrimitive("1969-07-21T12:56:00+10:00"))
+        serialized.add("ot", JsonPrimitive("12:56:00+10:00"))
+        serialized.add("zdt", JsonPrimitive("1969-07-21T12:56:00+10:00[Australia/Brisbane]"))
+        serialized.add("i", JsonPrimitive("1969-07-21T02:56:00Z"))
+
+        val jsonString = gson.toJson(serialized)
+        val deserialized = gson.fromJson<Container>(jsonString, Container::class.java)
+
+        assertThat<LocalDate>(deserialized.ld, `is`<LocalDate>(container.ld))
+        assertThat<LocalDateTime>(deserialized.ldt, `is`<LocalDateTime>(container.ldt))
+        assertThat<LocalTime>(deserialized.lt, `is`<LocalTime>(container.lt))
+        assertThat<OffsetDateTime>(deserialized.odt, `is`<OffsetDateTime>(container.odt))
+        assertThat<OffsetTime>(deserialized.ot, `is`<OffsetTime>(container.ot))
+        assertThat<ZonedDateTime>(deserialized.zdt, `is`<ZonedDateTime>(container.zdt))
+        assertThat<Instant>(deserialized.i, `is`<Instant>(container.i))
+    }
+
+    /**
+     * Container for serialising many fields.
+     */
+    private class Container {
+        var ld: LocalDate? = null
+        var ldt: LocalDateTime? = null
+        var lt: LocalTime? = null
+        var odt: OffsetDateTime? = null
+        var ot: OffsetTime? = null
+        var zdt: ZonedDateTime? = null
+        var i: Instant? = null
+    }
+}