Jackson - Bidirectional Reference

Furkan Danismaz · Furkan Danismaz · commit 186c73305962 · 2019-06-12T15:07:26.000+03:00
diff --git a/jackson-bidirectional-relation/pom.xml b/jackson-bidirectional-relation/pom.xml
@@ -0,0 +1,37 @@
+<?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>
+
+    <groupId>com.fd</groupId>
+    <artifactId>jackson-bidirectional-relation</artifactId>
+    <version>1.0-SNAPSHOT</version>
+
+    <properties>
+        <java-version>1.8</java-version>
+        <maven.compiler.source>1.8</maven.compiler.source>
+        <maven.compiler.target>1.8</maven.compiler.target>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-databind</artifactId>
+            <version>2.9.8</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <version>1.18.8</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.testng</groupId>
+            <artifactId>testng</artifactId>
+            <version>6.14.3</version>
+        </dependency>
+    </dependencies>
+
+</project>
diff --git a/jackson-bidirectional-relation/src/main/java/com/fd/jackson/bidirectional/model/Item.java b/jackson-bidirectional-relation/src/main/java/com/fd/jackson/bidirectional/model/Item.java
@@ -0,0 +1,19 @@
+package com.fd.jackson.bidirectional.model;
+
+import com.fasterxml.jackson.annotation.JsonManagedReference;
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+@Getter
+@Setter
+@AllArgsConstructor
+@NoArgsConstructor
+public class Item {
+    private int id;
+    private String itemName;
+
+    @JsonManagedReference
+    private User owner;
+}
diff --git a/jackson-bidirectional-relation/src/main/java/com/fd/jackson/bidirectional/model/User.java b/jackson-bidirectional-relation/src/main/java/com/fd/jackson/bidirectional/model/User.java
@@ -0,0 +1,30 @@
+package com.fd.jackson.bidirectional.model;
+
+import com.fasterxml.jackson.annotation.JsonBackReference;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+import java.util.ArrayList;
+import java.util.List;
+
+@Getter
+@Setter
+@NoArgsConstructor
+public class User {
+
+    private int id;
+    private String name;
+
+    @JsonBackReference
+    private List<Item> userItems = new ArrayList<>();
+
+    public User(int id, String name) {
+        this.id = id;
+        this.name = name;
+    }
+
+    public void addItem(Item item) {
+        this.userItems.add(item);
+    }
+}
diff --git a/jackson-bidirectional-relation/src/test/java/BidirectionalMappingTest.java b/jackson-bidirectional-relation/src/test/java/BidirectionalMappingTest.java
@@ -0,0 +1,31 @@
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fd.jackson.bidirectional.model.Item;
+import com.fd.jackson.bidirectional.model.User;
+import org.testng.annotations.Test;
+
+public class BidirectionalMappingTest {
+
+    @Test //(expectedExceptions = JsonMappingException.class)
+    public void givenBidirectionRelation_whenSerializingItem_thenException()
+            throws JsonProcessingException {
+
+        User user = new User(1, "John");
+        Item item = new Item(2, "book", user);
+        user.addItem(item);
+
+        System.out.println(new ObjectMapper().writeValueAsString(item));
+    }
+
+    @Test //(expectedExceptions = JsonMappingException.class)
+    public void givenBidirectionRelation_whenSerializingUser_thenException()
+            throws JsonProcessingException {
+
+        User user = new User(1, "John");
+        Item item = new Item(2, "book", user);
+        user.addItem(item);
+
+        System.out.println(new ObjectMapper().writeValueAsString(user));
+    }
+
+}
