jackson support for kotlin

Author: Doha2012

kotlin-libraries-2/.gitignore

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+/bin/
+
+#ignore gradle
+.gradle/
+
+
+#ignore build and generated files
+build/
+node/
+out/
+
+#ignore installed node modules and package lock file
+node_modules/
+package-lock.json

kotlin-libraries-2/README.md

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+## Relevant articles:

kotlin-libraries-2/pom.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+ xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+ <modelVersion>4.0.0</modelVersion>
+ <artifactId>kotlin-libraries-2</artifactId>
+ <name>kotlin-libraries-2</name>
+ <packaging>jar</packaging>
+
+ <parent>
+ <groupId>com.baeldung</groupId>
+ <artifactId>parent-kotlin</artifactId>
+ <version>1.0.0-SNAPSHOT</version>
+ <relativePath>../parent-kotlin</relativePath>
+ </parent>
+
+ <dependencies>
+ <dependency>
+ <groupId>com.fasterxml.jackson.module</groupId>
+ <artifactId>jackson-module-kotlin</artifactId>
+ </dependency>
+ <dependency>
+ <groupId>junit</groupId>
+ <artifactId>junit</artifactId>
+ <scope>test</scope>
+ </dependency>
+
+
+ 
+ </dependencies>
+
+ <properties>
+ </properties>
+
+</project>

kotlin-libraries-2/resources/logback.xml

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+<configuration>
+ <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+ <encoder>
+ <pattern>%d{YYYY-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
+ </encoder>
+ </appender>
+
+ <root level="INFO">
+ <appender-ref ref="STDOUT"/>
+ </root>
+</configuration>

kotlin-libraries-2/src/main/kotlin/com/baeldung/kotlin/jackson/Book.kt

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+package com.baeldung.kotlin.jackson
+
+import com.fasterxml.jackson.annotation.*
+
+@JsonInclude(JsonInclude.Include.NON_EMPTY)
+data class Book(var title: String, @JsonProperty("author") var authorName: String) {
+ var genres: List<String>? = emptyList()
+}

kotlin-libraries-2/src/main/kotlin/com/baeldung/kotlin/jackson/Movie.kt

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+package com.baeldung.kotlin.jackson
+
+data class Movie(var name: String, var studio: String, var rating: Float? = 1f)

kotlin-libraries-2/src/test/kotlin/com/baeldung/kotlin/jackson/JacksonUnitTest.kt

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+package com.baeldung.kotlin.jackson
+
+import org.junit.Test
+import kotlin.test.assertTrue
+import kotlin.test.assertFalse
+import kotlin.test.assertEquals
+import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
+import com.fasterxml.jackson.module.kotlin.readValue
+import com.fasterxml.jackson.databind.ObjectMapper
+import com.fasterxml.jackson.module.kotlin.KotlinModule
+
+class JacksonUnitTest {
+ //val mapper = jacksonObjectMapper() 
+ val mapper = ObjectMapper().registerModule(KotlinModule())
+ 
+
+ @Test
+ fun whenSerializeMovie_thenSuccess() { 
+ val movie = Movie("Endgame", "Marvel", 9.2f)
+ val serialized = mapper.writeValueAsString(movie)
+ 
+ val json = """{"name":"Endgame","studio":"Marvel","rating":9.2}"""
+ assertEquals(serialized, json) 
+ }
+ 
+ @Test
+ fun whenDeserializeMovie_thenSuccess() { 
+ val json = """{"name":"Endgame","studio":"Marvel","rating":9.2}"""
+ // val movie: Movie = mapper.readValue(json)
+ val movie = mapper.readValue<Movie>(json)
+ 
+ assertEquals(movie.name, "Endgame") 
+ assertEquals(movie.studio, "Marvel") 
+ assertEquals(movie.rating, 9.2f) 
+ }
+ 
+ @Test
+ fun whenDeserializeMovieWithMissingValue_thenUseDefaultValue() { 
+ val json = """{"name":"Endgame","studio":"Marvel"}"""
+ val movie: Movie = mapper.readValue(json)
+ 
+ assertEquals(movie.name, "Endgame") 
+ assertEquals(movie.studio, "Marvel") 
+ assertEquals(movie.rating, 1f) 
+ } 
+ 
+ @Test
+ fun whenSerializeMap_thenSuccess() { 
+ val map = mapOf(1 to "one", 2 to "two")
+ val serialized = mapper.writeValueAsString(map)
+ 
+ val json = """{"1":"one","2":"two"}"""
+ assertEquals(serialized, json) 
+ } 
+ 
+ @Test
+ fun whenDeserializeMap_thenSuccess() { 
+ val json = """{"1":"one","2":"two"}"""
+ val aMap: Map<Int,String> = mapper.readValue(json)
+ 
+ assertEquals(aMap[1], "one") 
+ assertEquals(aMap[2], "two") 
+ }
+ 
+ @Test
+ fun whenSerializeList_thenSuccess() {
+ val movie1 = Movie("Endgame", "Marvel", 9.2f)
+ val movie2 = Movie("Shazam", "Warner Bros", 7.6f)
+ val movieList = listOf(movie1, movie2)
+ val serialized = mapper.writeValueAsString(movieList)
+ 
+ val json = """[{"name":"Endgame","studio":"Marvel","rating":9.2},{"name":"Shazam","studio":"Warner Bros","rating":7.6}]"""
+ assertEquals(serialized, json) 
+ }
+ 
+ @Test
+ fun whenDeserializeList_thenSuccess() {
+ val json = """[{"name":"Endgame","studio":"Marvel","rating":9.2},{"name":"Shazam","studio":"Warner Bros","rating":7.6}]"""
+ val movieList: List<Movie> = mapper.readValue(json)
+ 
+ val movie1 = Movie("Endgame", "Marvel", 9.2f)
+ val movie2 = Movie("Shazam", "Warner Bros", 7.6f)
+ assertTrue(movieList.contains(movie1)) 
+ assertTrue(movieList.contains(movie2)) 
+ }
+ 
+ @Test
+ fun whenSerializeBook_thenSuccess() { 
+ val book = Book("Oliver Twist", "Charles Dickens")
+ val serialized = mapper.writeValueAsString(book)
+ 
+ val json = """{"title":"Oliver Twist","author":"Charles Dickens"}"""
+ assertEquals(serialized, json) 
+ } 
+ 
+ @Test
+ fun whenDeserializeBook_thenSuccess() { 
+ val json = """{"title":"Oliver Twist","author":"Charles Dickens"}"""
+ val book: Book = mapper.readValue(json)
+ 
+ assertEquals(book.title, "Oliver Twist") 
+ assertEquals(book.authorName, "Charles Dickens") 
+ }
+
+ @Test
+ fun givenJsonInclude_whenSerializeBook_thenEmptyFieldExcluded() { 
+ val book = Book("Oliver Twist", "Charles Dickens")
+ val serialized = mapper.writeValueAsString(book)
+ 
+ val json = """{"title":"Oliver Twist","author":"Charles Dickens"}"""
+ assertEquals(serialized, json) 
+ }
+ 
+}