Jsonb

Author: Nikita Konev

pom.xml

@@ -21,6 +21,10 @@
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-starter-data-jdbc</artifactId>
 		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-json</artifactId>
+		</dependency>
 		<dependency>
 			<groupId>com.fasterxml.jackson.module</groupId>
 			<artifactId>jackson-module-kotlin</artifactId>
@@ -66,6 +70,8 @@
 					<compilerPlugins>
 						<plugin>spring</plugin>
 					</compilerPlugins>
+					<!-- https://kotlinlang.org/docs/maven.html#specifying-compiler-options current kotlin yet not supports Java 17 target -->
+					<jvmTarget>16</jvmTarget>
 				</configuration>
 				<dependencies>
 					<dependency>

src/main/kotlin/com/example/web/jdbc/web/jdbc/Application.kt

@@ -27,9 +27,11 @@ class AppRunner(private val subjectRepository: SubjectRepository,
         val subj1: Subject = subjectRepository.save(Subject(0, "Software Engineering", "Apply key aspects of software engineering processes for the development of a complex software system"))
         val subj2: Subject = subjectRepository.save(Subject(0, "Distributed System", "Explore recent advances in distributed computing systems"))
         val subj3: Subject = subjectRepository.save(Subject(0, "Business Analysis and Optimization", "understand the Internal and external factors that impact the business strategy"))
+
         val branch1: Branch = Branch(0, "Computer Science and Engineering", "CSE", "CSE department offers courses under ambitious curricula in computer science and computer engineering..")
         branch1.addSubject(subj1)
         branch1.addSubject(subj2)
+        branch1.branchData = BranchData("Classic office", 100, "A pretty good office")
         val createdBranch1: Branch = branchRepository.save(branch1)
         logger.info("Created first branch {}", createdBranch1)
 

src/main/kotlin/com/example/web/jdbc/web/jdbc/Entities.kt

@@ -17,10 +17,13 @@ data class Branch(
     @Column("branch_short_name") var branchShortName: String,
     var description: String? = null,
     @MappedCollection(idColumn = "branch_id")
-    private val subjects: MutableSet<SubjectRef> = HashSet()
+    private val subjects: MutableSet<SubjectRef> = HashSet(),
+    var branchData: BranchData? = null
 ) {
 
     fun addSubject(subject: Subject) {
         subjects.add(SubjectRef(subject.subjectId.toLong()))
     }
-}
+}
+
+data class BranchData(val buildingType: String?, var rating: Int, var comment: String?)

src/main/kotlin/com/example/web/jdbc/web/jdbc/JdbcConfig.kt

@@ -0,0 +1,45 @@
+package com.example.web.jdbc.web.jdbc
+
+import com.fasterxml.jackson.databind.ObjectMapper
+import org.postgresql.util.PGobject
+import org.springframework.context.annotation.Configuration
+import org.springframework.core.convert.converter.Converter
+import org.springframework.data.convert.ReadingConverter
+import org.springframework.data.convert.WritingConverter
+import org.springframework.data.jdbc.core.convert.JdbcCustomConversions
+import org.springframework.data.jdbc.repository.config.AbstractJdbcConfiguration
+
+abstract class AbstractJsonWritingConverter<T> (
+        private val objectMapper: ObjectMapper
+) : Converter<T, PGobject> {
+    override fun convert(source: T): PGobject {
+        val jsonObject = PGobject()
+        jsonObject.type = "json"
+        jsonObject.value = objectMapper.writeValueAsString(source)
+        return jsonObject
+    }
+}
+
+abstract class AbstractJsonReadingConverter<T>(
+        private val objectMapper: ObjectMapper,
+        private val valueType: Class<T>
+) : Converter<PGobject, T> {
+    override fun convert(pgObject: PGobject): T? {
+        val source = pgObject.value
+        return objectMapper.readValue(source, valueType)
+    }
+}
+
+@Configuration
+class JdbcConfig(private val objectMapper: ObjectMapper) : AbstractJdbcConfiguration() {
+
+    override fun userConverters() = listOf(
+        PersonDataWritingConverter(objectMapper), PersonDataReadingConverter(objectMapper),
+    )
+}
+
+@WritingConverter
+class PersonDataWritingConverter(objectMapper: ObjectMapper) : AbstractJsonWritingConverter<BranchData>(objectMapper)
+
+@ReadingConverter
+class PersonDataReadingConverter(objectMapper: ObjectMapper) : AbstractJsonReadingConverter<BranchData>(objectMapper, BranchData::class.java)

src/main/resources/db/changelog.yml

@@ -2,7 +2,12 @@ databaseChangeLog:
   - changeSet:
       id: 1
       author: nkonev
-
       changes:
         - sqlFile:
-            path: /db/changelog/1648380286__init.sql
+            path: /db/changelog/1648380286__init.sql
+  - changeSet:
+      id: 2
+      author: nkonev
+      changes:
+        - sqlFile:
+            path: /db/changelog/1648459518__branch_data_jsonb.sql

src/main/resources/db/changelog/1648459518__branch_data_jsonb.sql

@@ -0,0 +1 @@
+ALTER TABLE BRANCH ADD COLUMN branch_data JSONB;