Merge pull request #108 from Doha2012/master

Add jackson bidirectional relationship test

jackson/src/test/java/org/baeldung/jackson/bidirection/CustomListDeserializer.java

@@ -0,0 +1,19 @@
+package org.baeldung.jackson.bidirection;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.JsonDeserializer;
+
+public class CustomListDeserializer extends JsonDeserializer<List<ItemWithSerializer>> {
+
+    @Override
+    public List<ItemWithSerializer> deserialize(final JsonParser jsonparser, final DeserializationContext context) throws IOException, JsonProcessingException {
+        return new ArrayList<ItemWithSerializer>();
+    }
+
+}

jackson/src/test/java/org/baeldung/jackson/bidirection/CustomListSerializer.java

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+package org.baeldung.jackson.bidirection;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.JsonSerializer;
+import com.fasterxml.jackson.databind.SerializerProvider;
+
+public class CustomListSerializer extends JsonSerializer<List<ItemWithSerializer>> {
+
+    @Override
+    public void serialize(final List<ItemWithSerializer> items, final JsonGenerator generator, final SerializerProvider provider) throws IOException, JsonProcessingException {
+        final List<Integer> ids = new ArrayList<Integer>();
+        for (final ItemWithSerializer item : items) {
+            ids.add(item.id);
+        }
+        generator.writeObject(ids);
+    }
+}

jackson/src/test/java/org/baeldung/jackson/bidirection/Item.java

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+package org.baeldung.jackson.bidirection;
+
+
+public class Item {
+    public int id;
+    public String itemName;
+    public User owner;
+
+    public Item() {
+        super();
+    }
+
+    public Item(final int id, final String itemName, final User owner) {
+        this.id = id;
+        this.itemName = itemName;
+        this.owner = owner;
+    }
+}

jackson/src/test/java/org/baeldung/jackson/bidirection/ItemWithIdentity.java

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+package org.baeldung.jackson.bidirection;
+
+import com.fasterxml.jackson.annotation.JsonIdentityInfo;
+import com.fasterxml.jackson.annotation.ObjectIdGenerators;
+
+@JsonIdentityInfo(generator = ObjectIdGenerators.PropertyGenerator.class, property = "id")
+public class ItemWithIdentity {
+    public int id;
+    public String itemName;
+    public UserWithIdentity owner;
+
+    public ItemWithIdentity() {
+        super();
+    }
+
+    public ItemWithIdentity(final int id, final String itemName, final UserWithIdentity owner) {
+        this.id = id;
+        this.itemName = itemName;
+        this.owner = owner;
+    }
+}

jackson/src/test/java/org/baeldung/jackson/bidirection/ItemWithIgnore.java

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+package org.baeldung.jackson.bidirection;
+
+
+public class ItemWithIgnore {
+    public int id;
+    public String itemName;
+    public UserWithIgnore owner;
+
+    public ItemWithIgnore() {
+        super();
+    }
+
+    public ItemWithIgnore(final int id, final String itemName, final UserWithIgnore owner) {
+        this.id = id;
+        this.itemName = itemName;
+        this.owner = owner;
+    }
+}

jackson/src/test/java/org/baeldung/jackson/bidirection/ItemWithRef.java

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+package org.baeldung.jackson.bidirection;
+
+import com.fasterxml.jackson.annotation.JsonManagedReference;
+
+public class ItemWithRef {
+    public int id;
+    public String itemName;
+
+    @JsonManagedReference
+    public UserWithRef owner;
+
+    public ItemWithRef() {
+        super();
+    }
+
+    public ItemWithRef(final int id, final String itemName, final UserWithRef owner) {
+        this.id = id;
+        this.itemName = itemName;
+        this.owner = owner;
+    }
+}

jackson/src/test/java/org/baeldung/jackson/bidirection/ItemWithSerializer.java

@@ -0,0 +1,18 @@
+package org.baeldung.jackson.bidirection;
+
+
+public class ItemWithSerializer {
+    public int id;
+    public String itemName;
+    public UserWithSerializer owner;
+
+    public ItemWithSerializer() {
+        super();
+    }
+
+    public ItemWithSerializer(final int id, final String itemName, final UserWithSerializer owner) {
+        this.id = id;
+        this.itemName = itemName;
+        this.owner = owner;
+    }
+}

jackson/src/test/java/org/baeldung/jackson/bidirection/User.java

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+package org.baeldung.jackson.bidirection;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class User {
+    public int id;
+    public String name;
+    public List<Item> userItems;
+
+    public User() {
+        super();
+    }
+
+    public User(final int id, final String name) {
+        this.id = id;
+        this.name = name;
+        userItems = new ArrayList<Item>();
+    }
+
+    public void addItem(final Item item) {
+        userItems.add(item);
+    }
+}

jackson/src/test/java/org/baeldung/jackson/bidirection/UserWithIdentity.java

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+package org.baeldung.jackson.bidirection;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import com.fasterxml.jackson.annotation.JsonIdentityInfo;
+import com.fasterxml.jackson.annotation.ObjectIdGenerators;
+
+@JsonIdentityInfo(generator = ObjectIdGenerators.PropertyGenerator.class, property = "id")
+public class UserWithIdentity {
+    public int id;
+    public String name;
+    public List<ItemWithIdentity> userItems;
+
+    public UserWithIdentity() {
+        super();
+    }
+
+    public UserWithIdentity(final int id, final String name) {
+        this.id = id;
+        this.name = name;
+        userItems = new ArrayList<ItemWithIdentity>();
+    }
+
+    public void addItem(final ItemWithIdentity item) {
+        userItems.add(item);
+    }
+}

jackson/src/test/java/org/baeldung/jackson/bidirection/UserWithIgnore.java

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+package org.baeldung.jackson.bidirection;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import com.fasterxml.jackson.annotation.JsonIgnore;
+
+public class UserWithIgnore {
+    public int id;
+    public String name;
+
+    @JsonIgnore
+    public List<ItemWithIgnore> userItems;
+
+    public UserWithIgnore() {
+        super();
+    }
+
+    public UserWithIgnore(final int id, final String name) {
+        this.id = id;
+        this.name = name;
+        userItems = new ArrayList<ItemWithIgnore>();
+    }
+
+    public void addItem(final ItemWithIgnore item) {
+        userItems.add(item);
+    }
+}

jackson/src/test/java/org/baeldung/jackson/bidirection/UserWithRef.java

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+package org.baeldung.jackson.bidirection;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import com.fasterxml.jackson.annotation.JsonBackReference;
+
+public class UserWithRef {
+    public int id;
+    public String name;
+
+    @JsonBackReference
+    public List<ItemWithRef> userItems;
+
+    public UserWithRef() {
+        super();
+    }
+
+    public UserWithRef(final int id, final String name) {
+        this.id = id;
+        this.name = name;
+        userItems = new ArrayList<ItemWithRef>();
+    }
+
+    public void addItem(final ItemWithRef item) {
+        userItems.add(item);
+    }
+}

jackson/src/test/java/org/baeldung/jackson/bidirection/UserWithSerializer.java

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+package org.baeldung.jackson.bidirection;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+import com.fasterxml.jackson.databind.annotation.JsonSerialize;
+
+public class UserWithSerializer {
+    public int id;
+    public String name;
+
+    @JsonSerialize(using = CustomListSerializer.class)
+    @JsonDeserialize(using = CustomListDeserializer.class)
+    public List<ItemWithSerializer> userItems;
+
+    public UserWithSerializer() {
+        super();
+    }
+
+    public UserWithSerializer(final int id, final String name) {
+        this.id = id;
+        this.name = name;
+        userItems = new ArrayList<ItemWithSerializer>();
+    }
+
+    public void addItem(final ItemWithSerializer item) {
+        userItems.add(item);
+    }
+}

jackson/src/test/java/org/baeldung/jackson/test/JacksonBidirectionRelationTest.java

@@ -0,0 +1,119 @@
+package org.baeldung.jackson.test;
+
+import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.not;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertThat;
+
+import java.io.IOException;
+
+import org.baeldung.jackson.bidirection.Item;
+import org.baeldung.jackson.bidirection.ItemWithIdentity;
+import org.baeldung.jackson.bidirection.ItemWithIgnore;
+import org.baeldung.jackson.bidirection.ItemWithRef;
+import org.baeldung.jackson.bidirection.ItemWithSerializer;
+import org.baeldung.jackson.bidirection.User;
+import org.baeldung.jackson.bidirection.UserWithIdentity;
+import org.baeldung.jackson.bidirection.UserWithIgnore;
+import org.baeldung.jackson.bidirection.UserWithRef;
+import org.baeldung.jackson.bidirection.UserWithSerializer;
+import org.junit.Test;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+public class JacksonBidirectionRelationTest {
+
+    @Test(expected = JsonMappingException.class)
+    public void givenBidirectionRelation_whenSerialize_thenException() throws JsonProcessingException {
+        final User user = new User(1, "John");
+        final Item item = new Item(2, "book", user);
+        user.addItem(item);
+
+        final ObjectMapper mapper = new ObjectMapper();
+        mapper.writeValueAsString(item);
+    }
+
+    @Test
+    public void givenBidirectionRelation_whenUseJacksonReferenceAnnotation_thenCorrect() throws JsonProcessingException {
+        final UserWithRef user = new UserWithRef(1, "John");
+        final ItemWithRef item = new ItemWithRef(2, "book", user);
+        user.addItem(item);
+
+        final ObjectMapper mapper = new ObjectMapper();
+        final String result = mapper.writeValueAsString(item);
+
+        assertThat(result, containsString("book"));
+        assertThat(result, containsString("John"));
+        assertThat(result, not(containsString("userItems")));
+    }
+
+    @Test
+    public void givenBidirectionRelation_whenUseJsonIdentityInfo_thenCorrect() throws JsonProcessingException {
+        final UserWithIdentity user = new UserWithIdentity(1, "John");
+        final ItemWithIdentity item = new ItemWithIdentity(2, "book", user);
+        user.addItem(item);
+
+        final ObjectMapper mapper = new ObjectMapper();
+        final String result = mapper.writeValueAsString(item);
+
+        assertThat(result, containsString("book"));
+        assertThat(result, containsString("John"));
+        assertThat(result, containsString("userItems"));
+    }
+
+    @Test
+    public void givenBidirectionRelation_whenUseJsonIgnore_thenCorrect() throws JsonProcessingException {
+        final UserWithIgnore user = new UserWithIgnore(1, "John");
+        final ItemWithIgnore item = new ItemWithIgnore(2, "book", user);
+        user.addItem(item);
+
+        final ObjectMapper mapper = new ObjectMapper();
+        final String result = mapper.writeValueAsString(item);
+
+        assertThat(result, containsString("book"));
+        assertThat(result, containsString("John"));
+        assertThat(result, not(containsString("userItems")));
+    }
+
+    @Test
+    public void givenBidirectionRelation_whenUseCustomSerializer_thenCorrect() throws JsonProcessingException {
+        final UserWithSerializer user = new UserWithSerializer(1, "John");
+        final ItemWithSerializer item = new ItemWithSerializer(2, "book", user);
+        user.addItem(item);
+
+        final ObjectMapper mapper = new ObjectMapper();
+        final String result = mapper.writeValueAsString(item);
+
+        assertThat(result, containsString("book"));
+        assertThat(result, containsString("John"));
+        assertThat(result, containsString("userItems"));
+    }
+
+    @Test
+    public void givenBidirectionRelation_whenDeserializeUsingIdentity_thenCorrect() throws JsonProcessingException, IOException {
+        final String json = "{\"id\":2,\"itemName\":\"book\",\"owner\":{\"id\":1,\"name\":\"John\",\"userItems\":[2]}}";
+
+        final ObjectMapper mapper = new ObjectMapper();
+
+        final ItemWithIdentity item = mapper.reader(ItemWithIdentity.class).readValue(json);
+        assertEquals(2, item.id);
+        assertEquals("book", item.itemName);
+        assertEquals("John", item.owner.name);
+    }
+
+    @Test
+    public void givenBidirectionRelation_whenUseCustomDeserializer_thenCorrect() throws JsonProcessingException, IOException {
+        final String json = "{\"id\":2,\"itemName\":\"book\",\"owner\":{\"id\":1,\"name\":\"John\",\"userItems\":[2]}}";
+
+        final ObjectMapper mapper = new ObjectMapper();
+
+        final ItemWithSerializer item = mapper.reader(ItemWithSerializer.class).readValue(json);
+        assertEquals(2, item.id);
+        assertEquals("book", item.itemName);
+        assertEquals("John", item.owner.name);
+    }
+
+}
+