[BAEL-19676] - Move articles out of jackson part 3

jackson-custom-conversions/src/main/java/com/baeldung/defaultserializercustomserializer/File.java

@@ -0,0 +1,25 @@
+package com.baeldung.defaultserializercustomserializer;
+
+public class File {
+
+    private Long id;
+
+    private String name;
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+}

jackson-custom-conversions/src/main/java/com/baeldung/defaultserializercustomserializer/Folder.java

@@ -0,0 +1,82 @@
+package com.baeldung.defaultserializercustomserializer;
+
+import java.util.ArrayList;
+import java.util.Date;
+import java.util.List;
+
+import com.fasterxml.jackson.annotation.JsonIgnore;
+
+public class Folder {
+
+    private Long id;
+
+    private String name;
+
+    private String owner;
+
+    private Date created;
+
+    private Date modified;
+
+    private Date lastAccess;
+
+    @JsonIgnore
+    private List<File> files = new ArrayList<>();
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getOwner() {
+        return owner;
+    }
+
+    public void setOwner(String owner) {
+        this.owner = owner;
+    }
+
+    public Date getCreated() {
+        return created;
+    }
+
+    public void setCreated(Date created) {
+        this.created = created;
+    }
+
+    public Date getModified() {
+        return modified;
+    }
+
+    public void setModified(Date modified) {
+        this.modified = modified;
+    }
+
+    public Date getLastAccess() {
+        return lastAccess;
+    }
+
+    public void setLastAccess(Date lastAccess) {
+        this.lastAccess = lastAccess;
+    }
+
+    public List<File> getFiles() {
+        return files;
+    }
+
+    public void setFiles(List<File> files) {
+        this.files = files;
+    }
+
+}

jackson-custom-conversions/src/main/java/com/baeldung/defaultserializercustomserializer/FolderBeanSerializerModifier.java

@@ -0,0 +1,20 @@
+package com.baeldung.defaultserializercustomserializer;
+
+import com.fasterxml.jackson.databind.BeanDescription;
+import com.fasterxml.jackson.databind.JsonSerializer;
+import com.fasterxml.jackson.databind.SerializationConfig;
+import com.fasterxml.jackson.databind.ser.BeanSerializerModifier;
+
+public class FolderBeanSerializerModifier extends BeanSerializerModifier {
+
+    @Override
+    public JsonSerializer<?> modifySerializer(SerializationConfig config, BeanDescription beanDesc, JsonSerializer<?> serializer) {
+
+        if (beanDesc.getBeanClass().equals(Folder.class)) {
+            return new FolderSerializerWithDefaultSerializerStored((JsonSerializer<Object>) serializer);
+        }
+
+        return serializer;
+    }
+
+}

jackson-custom-conversions/src/main/java/com/baeldung/defaultserializercustomserializer/FolderSerializer.java

@@ -0,0 +1,34 @@
+package com.baeldung.defaultserializercustomserializer;
+
+import java.io.IOException;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import com.fasterxml.jackson.databind.ser.std.StdSerializer;
+
+public class FolderSerializer extends StdSerializer<Folder> {
+
+    public FolderSerializer() {
+        super(Folder.class);
+    }
+
+    @Override
+    public void serialize(Folder value, JsonGenerator gen, SerializerProvider provider) throws IOException {
+
+        gen.writeStartObject();
+        gen.writeStringField("name", value.getName());
+
+        gen.writeArrayFieldStart("files");
+        for (File file : value.getFiles()) {
+            gen.writeStartObject();
+            gen.writeNumberField("id", file.getId());
+            gen.writeStringField("name", file.getName());
+            gen.writeEndObject();
+        }
+        gen.writeEndArray();
+
+        gen.writeEndObject();
+
+    }
+
+}

jackson-custom-conversions/src/main/java/com/baeldung/defaultserializercustomserializer/FolderSerializerWithCallingOwnSerializer.java

@@ -0,0 +1,29 @@
+package com.baeldung.defaultserializercustomserializer;
+
+import java.io.IOException;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import com.fasterxml.jackson.databind.ser.std.StdSerializer;
+
+public class FolderSerializerWithCallingOwnSerializer extends StdSerializer<Folder> {
+
+    public FolderSerializerWithCallingOwnSerializer() {
+        super(Folder.class);
+    }
+
+    @Override
+    public void serialize(Folder value, JsonGenerator gen, SerializerProvider provider) throws IOException {
+
+        gen.writeStartObject();
+        gen.writeStringField("name", value.getName());
+
+        provider.defaultSerializeField("files", value.getFiles(), gen);
+
+        provider.defaultSerializeField("details", value, gen);
+
+        gen.writeEndObject();
+
+    }
+
+}

jackson-custom-conversions/src/main/java/com/baeldung/defaultserializercustomserializer/FolderSerializerWithDefaultSerializerStored.java

@@ -0,0 +1,34 @@
+package com.baeldung.defaultserializercustomserializer;
+
+import java.io.IOException;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.databind.JsonSerializer;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import com.fasterxml.jackson.databind.ser.std.StdSerializer;
+
+public class FolderSerializerWithDefaultSerializerStored extends StdSerializer<Folder> {
+
+    private final JsonSerializer<Object> defaultSerializer;
+
+    public FolderSerializerWithDefaultSerializerStored(JsonSerializer<Object> defaultSerializer) {
+        super(Folder.class);
+        this.defaultSerializer = defaultSerializer;
+    }
+
+    @Override
+    public void serialize(Folder value, JsonGenerator gen, SerializerProvider provider) throws IOException {
+
+        gen.writeStartObject();
+        gen.writeStringField("name", value.getName());
+
+        provider.defaultSerializeField("files", value.getFiles(), gen);
+
+        gen.writeFieldName("details");
+        defaultSerializer.serialize(value, gen, provider);
+
+        gen.writeEndObject();
+
+    }
+
+}

jackson-custom-conversions/src/main/java/com/baeldung/defaultserializercustomserializer/FolderSerializerWithInternalObjectMapper.java

@@ -0,0 +1,33 @@
+package com.baeldung.defaultserializercustomserializer;
+
+import java.io.IOException;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import com.fasterxml.jackson.databind.ser.std.StdSerializer;
+
+public class FolderSerializerWithInternalObjectMapper extends StdSerializer<Folder> {
+
+    public FolderSerializerWithInternalObjectMapper() {
+        super(Folder.class);
+    }
+
+    @Override
+    public void serialize(Folder value, JsonGenerator gen, SerializerProvider provider) throws IOException {
+
+        gen.writeStartObject();
+        gen.writeStringField("name", value.getName());
+
+        // we access internal mapper to delegate the serialization of File list  
+        ObjectMapper mapper = (ObjectMapper) gen.getCodec();
+
+        gen.writeFieldName("files");
+        String stringValue = mapper.writeValueAsString(value.getFiles());
+        gen.writeRawValue(stringValue);
+
+        gen.writeEndObject();
+
+    }
+
+}

jackson-custom-conversions/src/main/java/com/baeldung/defaultserializercustomserializer/FolderSerializerWithSerializerProvider.java

@@ -0,0 +1,28 @@
+package com.baeldung.defaultserializercustomserializer;
+
+import java.io.IOException;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import com.fasterxml.jackson.databind.ser.std.StdSerializer;
+
+public class FolderSerializerWithSerializerProvider extends StdSerializer<Folder> {
+
+    public FolderSerializerWithSerializerProvider() {
+        super(Folder.class);
+    }
+
+    @Override
+    public void serialize(Folder value, JsonGenerator gen, SerializerProvider provider) throws IOException {
+
+        gen.writeStartObject();
+        gen.writeStringField("name", value.getName());
+
+        // we delegate the File list serialization to its default serializer
+        provider.defaultSerializeField("files", value.getFiles(), gen);
+
+        gen.writeEndObject();
+
+    }
+
+}

jackson-custom-conversions/src/main/java/com/baeldung/deserialization/ActorJackson.java

@@ -0,0 +1,61 @@
+package com.baeldung.deserialization;
+
+import java.text.DateFormat;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+import java.util.List;
+import java.util.Locale;
+import java.util.TimeZone;
+
+public class ActorJackson {
+
+    private String imdbId;
+    private Date dateOfBirth;
+    private List<String> filmography;
+
+    public ActorJackson() {
+        super();
+    }
+
+    public ActorJackson(String imdbId, Date dateOfBirth, List<String> filmography) {
+        super();
+        this.imdbId = imdbId;
+        this.dateOfBirth = dateOfBirth;
+        this.filmography = filmography;
+    }
+
+    @Override
+    public String toString() {
+        return "ActorJackson [imdbId=" + imdbId + ", dateOfBirth=" + formatDateOfBirth() + ", filmography=" + filmography + "]";
+    }
+
+    public String getImdbId() {
+        return imdbId;
+    }
+
+    public void setImdbId(String imdbId) {
+        this.imdbId = imdbId;
+    }
+
+    public Date getDateOfBirth() {
+        return dateOfBirth;
+    }
+
+    public void setDateOfBirth(Date dateOfBirth) {
+        this.dateOfBirth = dateOfBirth;
+    }
+
+    public List<String> getFilmography() {
+        return filmography;
+    }
+
+    public void setFilmography(List<String> filmography) {
+        this.filmography = filmography;
+    }
+
+    private String formatDateOfBirth() {
+        final DateFormat formatter = new SimpleDateFormat("EEE MMM dd hh:mm:ss zzz yyyy", Locale.US);
+        formatter.setTimeZone(TimeZone.getTimeZone("GMT"));
+        return formatter.format(dateOfBirth);
+    }
+}

jackson-custom-conversions/src/main/java/com/baeldung/deserialization/Item.java

@@ -0,0 +1,32 @@
+package com.baeldung.deserialization;
+
+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;
+    }
+
+    // API
+
+    public int getId() {
+        return id;
+    }
+
+    public String getItemName() {
+        return itemName;
+    }
+
+    public User getOwner() {
+        return owner;
+    }
+
+}

jackson-custom-conversions/src/main/java/com/baeldung/deserialization/ItemDeserializer.java

@@ -0,0 +1,39 @@
+package com.baeldung.deserialization;
+
+import java.io.IOException;
+
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.deser.std.StdDeserializer;
+import com.fasterxml.jackson.databind.node.IntNode;
+
+public class ItemDeserializer extends StdDeserializer<Item> {
+
+    private static final long serialVersionUID = 1883547683050039861L;
+
+    public ItemDeserializer() {
+        this(null);
+    }
+
+    public ItemDeserializer(final Class<?> vc) {
+        super(vc);
+    }
+
+    /**
+     * {"id":1,"itemNr":"theItem","owner":2}
+     */
+    @Override
+    public Item deserialize(final JsonParser jp, final DeserializationContext ctxt) throws IOException, JsonProcessingException {
+        final JsonNode node = jp.getCodec()
+            .readTree(jp);
+        final int id = (Integer) ((IntNode) node.get("id")).numberValue();
+        final String itemName = node.get("itemName")
+            .asText();
+        final int userId = (Integer) ((IntNode) node.get("createdBy")).numberValue();
+
+        return new Item(id, itemName, new User(userId, null));
+    }
+
+}

jackson-custom-conversions/src/main/java/com/baeldung/deserialization/ItemDeserializerOnClass.java

@@ -0,0 +1,39 @@
+package com.baeldung.deserialization;
+
+import java.io.IOException;
+
+import com.fasterxml.jackson.core.JsonParser;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.deser.std.StdDeserializer;
+import com.fasterxml.jackson.databind.node.IntNode;
+
+public class ItemDeserializerOnClass extends StdDeserializer<ItemWithDeserializer> {
+
+    private static final long serialVersionUID = 5579141241817332594L;
+
+    public ItemDeserializerOnClass() {
+        this(null);
+    }
+
+    public ItemDeserializerOnClass(final Class<?> vc) {
+        super(vc);
+    }
+
+    /**
+     * {"id":1,"itemNr":"theItem","owner":2}
+     */
+    @Override
+    public ItemWithDeserializer deserialize(final JsonParser jp, final DeserializationContext ctxt) throws IOException, JsonProcessingException {
+        final JsonNode node = jp.getCodec()
+            .readTree(jp);
+        final int id = (Integer) ((IntNode) node.get("id")).numberValue();
+        final String itemName = node.get("itemName")
+            .asText();
+        final int userId = (Integer) ((IntNode) node.get("owner")).numberValue();
+
+        return new ItemWithDeserializer(id, itemName, new User(userId, null));
+    }
+
+}

jackson-custom-conversions/src/main/java/com/baeldung/deserialization/ItemWithDeserializer.java

@@ -0,0 +1,31 @@
+package com.baeldung.deserialization;
+
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+
+@JsonDeserialize(using = ItemDeserializerOnClass.class)
+public class ItemWithDeserializer {
+    public final int id;
+    public final String itemName;
+    public final User owner;
+
+    public ItemWithDeserializer(final int id, final String itemName, final User owner) {
+        this.id = id;
+        this.itemName = itemName;
+        this.owner = owner;
+    }
+
+    // API
+
+    public int getId() {
+        return id;
+    }
+
+    public String getItemName() {
+        return itemName;
+    }
+
+    public User getOwner() {
+        return owner;
+    }
+
+}

jackson-custom-conversions/src/main/java/com/baeldung/deserialization/Movie.java

@@ -0,0 +1,50 @@
+package com.baeldung.deserialization;
+
+import java.util.List;
+
+public class Movie {
+
+    private String imdbId;
+    private String director;
+    private List<ActorJackson> actors;
+
+    public Movie(String imdbId, String director, List<ActorJackson> actors) {
+        super();
+        this.imdbId = imdbId;
+        this.director = director;
+        this.actors = actors;
+    }
+
+    public Movie() {
+        super();
+    }
+
+    @Override
+    public String toString() {
+        return "Movie [imdbId=" + imdbId + ", director=" + director + ", actors=" + actors + "]";
+    }
+
+    public String getImdbId() {
+        return imdbId;
+    }
+
+    public void setImdbId(String imdbId) {
+        this.imdbId = imdbId;
+    }
+
+    public String getDirector() {
+        return director;
+    }
+
+    public void setDirector(String director) {
+        this.director = director;
+    }
+
+    public List<ActorJackson> getActors() {
+        return actors;
+    }
+
+    public void setActors(List<ActorJackson> actors) {
+        this.actors = actors;
+    }
+}

jackson-custom-conversions/src/main/java/com/baeldung/deserialization/User.java

@@ -0,0 +1,26 @@
+package com.baeldung.deserialization;
+
+public class User {
+    public int id;
+    public String name;
+
+    public User() {
+        super();
+    }
+
+    public User(final int id, final String name) {
+        this.id = id;
+        this.name = name;
+    }
+
+    // API
+
+    public int getId() {
+        return id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+}

jackson-custom-conversions/src/main/java/com/baeldung/serialization/Item.java

@@ -0,0 +1,32 @@
+package com.baeldung.serialization;
+
+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;
+    }
+
+    // API
+
+    public int getId() {
+        return id;
+    }
+
+    public String getItemName() {
+        return itemName;
+    }
+
+    public User getOwner() {
+        return owner;
+    }
+
+}

jackson-custom-conversions/src/main/java/com/baeldung/serialization/ItemSerializer.java

@@ -0,0 +1,31 @@
+package com.baeldung.serialization;
+
+import java.io.IOException;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import com.fasterxml.jackson.databind.ser.std.StdSerializer;
+
+public class ItemSerializer extends StdSerializer<Item> {
+
+    private static final long serialVersionUID = 6739170890621978901L;
+
+    public ItemSerializer() {
+        this(null);
+    }
+
+    public ItemSerializer(final Class<Item> t) {
+        super(t);
+    }
+
+    @Override
+    public final void serialize(final Item value, final JsonGenerator jgen, final SerializerProvider provider) throws IOException, JsonProcessingException {
+        jgen.writeStartObject();
+        jgen.writeNumberField("id", value.id);
+        jgen.writeStringField("itemName", value.itemName);
+        jgen.writeNumberField("owner", value.owner.id);
+        jgen.writeEndObject();
+    }
+
+}

jackson-custom-conversions/src/main/java/com/baeldung/serialization/ItemSerializerOnClass.java

@@ -0,0 +1,31 @@
+package com.baeldung.serialization;
+
+import java.io.IOException;
+
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import com.fasterxml.jackson.databind.ser.std.StdSerializer;
+
+public class ItemSerializerOnClass extends StdSerializer<ItemWithSerializer> {
+
+    private static final long serialVersionUID = -1760959597313610409L;
+
+    public ItemSerializerOnClass() {
+        this(null);
+    }
+
+    public ItemSerializerOnClass(final Class<ItemWithSerializer> t) {
+        super(t);
+    }
+
+    @Override
+    public final void serialize(final ItemWithSerializer value, final JsonGenerator jgen, final SerializerProvider provider) throws IOException, JsonProcessingException {
+        jgen.writeStartObject();
+        jgen.writeNumberField("id", value.id);
+        jgen.writeStringField("itemName", value.itemName);
+        jgen.writeNumberField("owner", value.owner.id);
+        jgen.writeEndObject();
+    }
+
+}

jackson-custom-conversions/src/main/java/com/baeldung/serialization/ItemWithSerializer.java

@@ -0,0 +1,32 @@
+package com.baeldung.serialization;
+
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+import com.fasterxml.jackson.databind.annotation.JsonSerialize;
+
+@JsonSerialize(using = ItemSerializerOnClass.class)
+public class ItemWithSerializer {
+    public final int id;
+    public final String itemName;
+    public final User owner;
+
+    public ItemWithSerializer(final int id, final String itemName, final User owner) {
+        this.id = id;
+        this.itemName = itemName;
+        this.owner = owner;
+    }
+
+    // API
+
+    public int getId() {
+        return id;
+    }
+
+    public String getItemName() {
+        return itemName;
+    }
+
+    public User getOwner() {
+        return owner;
+    }
+
+}

jackson-custom-conversions/src/main/java/com/baeldung/serialization/User.java

@@ -0,0 +1,26 @@
+package com.baeldung.serialization;
+
+public class User {
+    public int id;
+    public String name;
+
+    public User() {
+        super();
+    }
+
+    public User(final int id, final String name) {
+        this.id = id;
+        this.name = name;
+    }
+
+    // API
+
+    public int getId() {
+        return id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+}

jackson-custom-conversions/src/main/java/com/baeldung/skipfields/Address.java

@@ -0,0 +1,40 @@
+package com.baeldung.skipfields;
+
+public class Address implements Hidable {
+    private String city;
+    private String country;
+    private boolean hidden;
+
+    public Address(final String city, final String country, final boolean hidden) {
+        super();
+        this.city = city;
+        this.country = country;
+        this.hidden = hidden;
+    }
+
+    public String getCity() {
+        return city;
+    }
+
+    public void setCity(final String city) {
+        this.city = city;
+    }
+
+    public String getCountry() {
+        return country;
+    }
+
+    public void setCountry(final String country) {
+        this.country = country;
+    }
+
+    @Override
+    public boolean isHidden() {
+        return hidden;
+    }
+
+    public void setHidden(final boolean hidden) {
+        this.hidden = hidden;
+    }
+
+}

jackson-custom-conversions/src/main/java/com/baeldung/skipfields/Hidable.java

@@ -0,0 +1,8 @@
+package com.baeldung.skipfields;
+
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+
+@JsonIgnoreProperties("hidden")
+public interface Hidable {
+    boolean isHidden();
+}

jackson-custom-conversions/src/main/java/com/baeldung/skipfields/HidableSerializer.java

@@ -0,0 +1,29 @@
+package com.baeldung.skipfields;
+
+import java.io.IOException;
+
+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 HidableSerializer extends JsonSerializer<Hidable> {
+
+    private JsonSerializer<Object> defaultSerializer;
+
+    public HidableSerializer(final JsonSerializer<Object> serializer) {
+        defaultSerializer = serializer;
+    }
+
+    @Override
+    public void serialize(final Hidable value, final JsonGenerator jgen, final SerializerProvider provider) throws IOException, JsonProcessingException {
+        if (value.isHidden())
+            return;
+        defaultSerializer.serialize(value, jgen, provider);
+    }
+
+    @Override
+    public boolean isEmpty(final SerializerProvider provider, final Hidable value) {
+        return (value == null || value.isHidden());
+    }
+}

jackson-custom-conversions/src/main/java/com/baeldung/skipfields/MyDtoWithFilter.java

@@ -0,0 +1,50 @@
+package com.baeldung.skipfields;
+
+import com.fasterxml.jackson.annotation.JsonFilter;
+
+@JsonFilter("myFilter")
+public class MyDtoWithFilter {
+
+    private String stringValue;
+    private int intValue;
+    private boolean booleanValue;
+
+    public MyDtoWithFilter() {
+        super();
+    }
+
+    public MyDtoWithFilter(final String stringValue, final int intValue, final boolean booleanValue) {
+        super();
+
+        this.stringValue = stringValue;
+        this.intValue = intValue;
+        this.booleanValue = booleanValue;
+    }
+
+    // API
+
+    public String getStringValue() {
+        return stringValue;
+    }
+
+    public void setStringValue(final String stringValue) {
+        this.stringValue = stringValue;
+    }
+
+    public int getIntValue() {
+        return intValue;
+    }
+
+    public void setIntValue(final int intValue) {
+        this.intValue = intValue;
+    }
+
+    public boolean isBooleanValue() {
+        return booleanValue;
+    }
+
+    public void setBooleanValue(final boolean booleanValue) {
+        this.booleanValue = booleanValue;
+    }
+
+}

jackson-custom-conversions/src/main/java/com/baeldung/skipfields/Person.java

@@ -0,0 +1,40 @@
+package com.baeldung.skipfields;
+
+public class Person implements Hidable {
+    private String name;
+    private Address address;
+    private boolean hidden;
+
+    public Person(final String name, final Address address, final boolean hidden) {
+        super();
+        this.name = name;
+        this.address = address;
+        this.hidden = hidden;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(final String name) {
+        this.name = name;
+    }
+
+    public Address getAddress() {
+        return address;
+    }
+
+    public void setAddress(final Address address) {
+        this.address = address;
+    }
+
+    @Override
+    public boolean isHidden() {
+        return hidden;
+    }
+
+    public void setHidden(final boolean hidden) {
+        this.hidden = hidden;
+    }
+
+}

jackson-custom-conversions/src/test/java/com/baeldung/defaultserializercustomserializer/CallingDefaultSerializerUnitTest.java

@@ -0,0 +1,164 @@
+package com.baeldung.defaultserializercustomserializer;
+
+import static org.junit.Assert.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.io.IOException;
+import java.time.Instant;
+import java.util.ArrayList;
+import java.util.Date;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import com.fasterxml.jackson.core.type.TypeReference;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.module.SimpleModule;
+
+public class CallingDefaultSerializerUnitTest {
+
+    private ObjectMapper mapper;
+    private Folder mockFolder;
+    private TypeReference<HashMap<String, Object>> mapType;
+
+    @Before
+    public void setup() {
+
+        mapType = new TypeReference<HashMap<String, Object>>() {
+        };
+
+        mapper = new ObjectMapper();
+
+        mockFolder = new Folder();
+        mockFolder.setId(1L);
+        mockFolder.setName("Root Folder");
+        mockFolder.setOwner("root");
+        mockFolder.setCreated(Date.from(Instant.now().minusSeconds(60)));
+        mockFolder.setModified(Date.from(Instant.now().minusSeconds(30)));
+        mockFolder.setLastAccess(Date.from(Instant.now()));
+
+        File file1 = new File();
+        file1.setId(1L);
+        file1.setName("File 1");
+
+        File file2 = new File();
+        file2.setId(2L);
+        file2.setName("File 2");
+
+        List<File> files = new ArrayList<>();
+        files.add(file1);
+        files.add(file2);
+        mockFolder.setFiles(files);
+
+    }
+
+    @Test
+    public void givenFolder_whenSerialized_onlyNameAndFilesFieldsSerialized() throws IOException {
+
+        SimpleModule module = new SimpleModule();
+        module.addSerializer(new FolderSerializer());
+        mapper.registerModule(module);
+
+        String json = mapper.writeValueAsString(mockFolder);
+
+        HashMap<String, Object> actual = mapper.readValue(json, mapType);
+
+        assertTrue(actual.containsKey("name"));
+        assertTrue(actual.containsKey("files"));
+        assertEquals(mockFolder.getName(), actual.get("name"));
+
+        List actualFiles = (List) actual.get("files");
+        assertEquals(mockFolder.getFiles().size(), actualFiles.size());
+        
+    }
+
+    @Test
+    public void givenFolder_whenSerializedWithSerializerProvider_onlyNameAndFilesFieldsSerialized() throws IOException {
+
+        SimpleModule module = new SimpleModule();
+        module.addSerializer(new FolderSerializerWithSerializerProvider());
+        mapper.registerModule(module);
+
+        String json = mapper.writeValueAsString(mockFolder);
+
+        HashMap<String, Object> actual = mapper.readValue(json, mapType);
+
+        assertTrue(actual.containsKey("name"));
+        assertTrue(actual.containsKey("files"));
+        assertEquals(mockFolder.getName(), actual.get("name"));
+
+        List actualFiles = (List) actual.get("files");
+        assertEquals(mockFolder.getFiles().size(), actualFiles.size());
+
+    }
+
+    @Test
+    public void givenFolder_whenSerializedWithInternalObjectMapper_onlyNameAndFilesFieldsSerialized() throws IOException {
+
+        SimpleModule module = new SimpleModule();
+        module.addSerializer(new FolderSerializerWithInternalObjectMapper());
+        mapper.registerModule(module);
+
+        String json = mapper.writeValueAsString(mockFolder);
+
+        HashMap<String, Object> actual = mapper.readValue(json, mapType);
+
+        assertTrue(actual.containsKey("name"));
+        assertTrue(actual.containsKey("files"));
+        assertEquals(mockFolder.getName(), actual.get("name"));
+
+        List actualFiles = (List) actual.get("files");
+        assertEquals(mockFolder.getFiles().size(), actualFiles.size());
+
+    }
+
+    @Test(expected = StackOverflowError.class)
+    public void givenFolder_whenSerializedWithCallingOwnSerializer_exceptionOccured() throws IOException {
+
+        SimpleModule module = new SimpleModule();
+        module.addSerializer(new FolderSerializerWithCallingOwnSerializer());
+        mapper.registerModule(module);
+
+        mapper.writeValueAsString(mockFolder);
+        
+    }
+
+    @Test
+    public void givenFolder_whenSerializedWithDefaultSerializerStored_NameAndFilesAndDetailsFieldsSerialized() throws IOException {
+
+        SimpleModule module = new SimpleModule();
+        module.setSerializerModifier(new FolderBeanSerializerModifier());
+        mapper.registerModule(module);
+
+        String json = mapper.writeValueAsString(mockFolder);
+        
+        HashMap<String, Object> actual = mapper.readValue(json, mapType);
+
+        assertTrue(actual.containsKey("name"));
+        assertTrue(actual.containsKey("files"));
+        assertEquals(mockFolder.getName(), actual.get("name"));
+
+        List actualFiles = (List) actual.get("files");
+        assertEquals(mockFolder.getFiles().size(), actualFiles.size());
+        
+        Map actualDetails = (Map) actual.get("details");
+        assertTrue(actualDetails.containsKey("id"));
+        assertTrue(actualDetails.containsKey("name"));
+        assertTrue(actualDetails.containsKey("owner"));
+        assertTrue(actualDetails.containsKey("created"));
+        assertTrue(actualDetails.containsKey("modified"));
+        assertTrue(actualDetails.containsKey("lastAccess"));
+        
+        assertEquals(mockFolder.getId().longValue(), ((Number)actualDetails.get("id")).longValue());
+        assertEquals(mockFolder.getName(), actualDetails.get("name"));
+        assertEquals(mockFolder.getOwner(), actualDetails.get("owner"));
+        assertEquals(mockFolder.getCreated(), new Date((long) actualDetails.get("created")));
+        assertEquals(mockFolder.getModified(), new Date((long) actualDetails.get("modified")));
+        assertEquals(mockFolder.getLastAccess(), new Date((long) actualDetails.get("lastAccess")));
+
+    }
+
+}

jackson-custom-conversions/src/test/java/com/baeldung/deserialization/CustomDeserializationUnitTest.java

@@ -0,0 +1,84 @@
+package com.baeldung.deserialization;
+
+import com.fasterxml.jackson.core.JsonParseException;
+import com.fasterxml.jackson.databind.DeserializationFeature;
+import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.SerializationFeature;
+import com.fasterxml.jackson.databind.module.SimpleModule;
+import org.junit.Test;
+
+import java.io.IOException;
+import java.time.ZoneId;
+import java.time.ZonedDateTime;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.CoreMatchers.not;
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.notNullValue;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertThat;
+
+public class CustomDeserializationUnitTest {
+
+    @Test
+    public final void whenDeserializingTheStandardRepresentation_thenCorrect() throws JsonParseException, JsonMappingException, IOException {
+        final String json = "{\"id\":1,\"itemName\":\"theItem\",\"owner\":{\"id\":2,\"name\":\"theUser\"}}";
+
+        final Item readValue = new ObjectMapper().readValue(json, Item.class);
+        assertThat(readValue, notNullValue());
+    }
+
+    @Test
+    public final void whenDeserializingANonStandardRepresentation_thenCorrect() throws JsonParseException, JsonMappingException, IOException {
+        final String json = "{\"id\":1,\"itemName\":\"theItem\",\"createdBy\":2}";
+        final ObjectMapper mapper = new ObjectMapper();
+
+        final SimpleModule module = new SimpleModule();
+        module.addDeserializer(Item.class, new ItemDeserializer());
+        mapper.registerModule(module);
+
+        final Item readValue = mapper.readValue(json, Item.class);
+        assertThat(readValue, notNullValue());
+    }
+
+    @Test
+    public final void givenDeserializerIsOnClass_whenDeserializingCustomRepresentation_thenCorrect() throws JsonParseException, JsonMappingException, IOException {
+        final String json = "{\"id\":1,\"itemName\":\"theItem\",\"owner\":2}";
+
+        final ItemWithDeserializer readValue = new ObjectMapper().readValue(json, ItemWithDeserializer.class);
+        assertThat(readValue, notNullValue());
+    }
+
+    @Test
+    public void whenDeserialisingZonedDateTimeWithDefaults_thenTimeZoneIsNotPreserved() throws IOException {
+        ObjectMapper objectMapper = new ObjectMapper();
+        objectMapper.findAndRegisterModules();
+        objectMapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
+        // construct a new instance of ZonedDateTime
+        ZonedDateTime now = ZonedDateTime.now(ZoneId.of("Europe/Berlin"));
+        String converted = objectMapper.writeValueAsString(now);
+        // restore an instance of ZonedDateTime from String
+        ZonedDateTime restored = objectMapper.readValue(converted, ZonedDateTime.class);
+        System.out.println("serialized: " + now);
+        System.out.println("restored: " + restored);
+        assertThat(now, is(not(restored)));
+    }
+
+    @Test
+    public void whenDeserialisingZonedDateTimeWithFeaturesDisabled_thenTimeZoneIsPreserved() throws IOException {
+        ObjectMapper objectMapper = new ObjectMapper();
+        objectMapper.findAndRegisterModules();
+        objectMapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
+        objectMapper.disable(DeserializationFeature.ADJUST_DATES_TO_CONTEXT_TIME_ZONE);
+        // construct a new instance of ZonedDateTime
+        ZonedDateTime now = ZonedDateTime.now(ZoneId.of("Europe/Berlin"));
+        String converted = objectMapper.writeValueAsString(now);
+        // restore an instance of ZonedDateTime from String
+        ZonedDateTime restored = objectMapper.readValue(converted, ZonedDateTime.class);
+        System.out.println("serialized: " + now);
+        System.out.println("restored: " + restored);
+        assertThat(now, is(restored));
+    }
+
+}

jackson-custom-conversions/src/test/java/com/baeldung/serialization/CustomSerializationUnitTest.java

@@ -0,0 +1,52 @@
+package com.baeldung.serialization;
+
+import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.not;
+import static org.hamcrest.Matchers.notNullValue;
+import static org.junit.Assert.assertThat;
+
+import java.io.IOException;
+import java.util.List;
+import org.junit.Test;
+
+import com.fasterxml.jackson.annotation.JsonAutoDetect.Visibility;
+import com.fasterxml.jackson.annotation.PropertyAccessor;
+import com.fasterxml.jackson.core.JsonGenerationException;
+import com.fasterxml.jackson.core.JsonParseException;
+import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.module.SimpleModule;
+import com.google.common.collect.Lists;
+
+public class CustomSerializationUnitTest {
+
+    @Test
+    public final void whenSerializing_thenNoExceptions() throws JsonGenerationException, JsonMappingException, IOException {
+        final Item myItem = new Item(1, "theItem", new User(2, "theUser"));
+        final String serialized = new ObjectMapper().writeValueAsString(myItem);
+        System.out.println(serialized);
+    }
+
+    @Test
+    public final void whenSerializingWithCustomSerializer_thenNoExceptions() throws JsonGenerationException, JsonMappingException, IOException {
+        final Item myItem = new Item(1, "theItem", new User(2, "theUser"));
+
+        final ObjectMapper mapper = new ObjectMapper();
+
+        final SimpleModule simpleModule = new SimpleModule();
+        simpleModule.addSerializer(Item.class, new ItemSerializer());
+        mapper.registerModule(simpleModule);
+
+        final String serialized = mapper.writeValueAsString(myItem);
+        System.out.println(serialized);
+    }
+
+    @Test
+    public final void givenSerializerRegisteredOnClass_whenSerializingWithCustomSerializer_thenNoExceptions() throws JsonGenerationException, JsonMappingException, IOException {
+        final ItemWithSerializer myItem = new ItemWithSerializer(1, "theItem", new User(2, "theUser"));
+
+        final String serialized = new ObjectMapper().writeValueAsString(myItem);
+        System.out.println(serialized);
+    }
+
+}

jackson-custom-conversions/src/test/java/com/baeldung/skipfields/IgnoreFieldsWithFilterUnitTest.java

@@ -0,0 +1,89 @@
+package com.baeldung.skipfields;
+
+import com.fasterxml.jackson.annotation.JsonInclude.Include;
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.core.JsonParseException;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.SerializerProvider;
+import com.fasterxml.jackson.databind.ser.BeanPropertyWriter;
+import com.fasterxml.jackson.databind.ser.FilterProvider;
+import com.fasterxml.jackson.databind.ser.PropertyFilter;
+import com.fasterxml.jackson.databind.ser.PropertyWriter;
+import com.fasterxml.jackson.databind.ser.impl.SimpleBeanPropertyFilter;
+import com.fasterxml.jackson.databind.ser.impl.SimpleFilterProvider;
+import org.junit.Test;
+
+import java.io.IOException;
+
+import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.not;
+import static org.junit.Assert.assertThat;
+
+public class IgnoreFieldsWithFilterUnitTest {
+
+    @Test
+    public final void givenTypeHasFilterThatIgnoresFieldByName_whenDtoIsSerialized_thenCorrect() throws JsonParseException, IOException {
+        final ObjectMapper mapper = new ObjectMapper();
+        final SimpleBeanPropertyFilter theFilter = SimpleBeanPropertyFilter.serializeAllExcept("intValue");
+        final FilterProvider filters = new SimpleFilterProvider().addFilter("myFilter", theFilter);
+
+        final MyDtoWithFilter dtoObject = new MyDtoWithFilter();
+        dtoObject.setIntValue(12);
+
+        final String dtoAsString = mapper.writer(filters)
+            .writeValueAsString(dtoObject);
+
+        assertThat(dtoAsString, not(containsString("intValue")));
+        assertThat(dtoAsString, containsString("booleanValue"));
+        assertThat(dtoAsString, containsString("stringValue"));
+        System.out.println(dtoAsString);
+    }
+
+    @Test
+    public final void givenTypeHasFilterThatIgnoresNegativeInt_whenDtoIsSerialized_thenCorrect() throws JsonParseException, IOException {
+        final PropertyFilter theFilter = new SimpleBeanPropertyFilter() {
+            @Override
+            public final void serializeAsField(final Object pojo, final JsonGenerator jgen, final SerializerProvider provider, final PropertyWriter writer) throws Exception {
+                if (include(writer)) {
+                    if (!writer.getName()
+                        .equals("intValue")) {
+                        writer.serializeAsField(pojo, jgen, provider);
+                        return;
+                    }
+
+                    final int intValue = ((MyDtoWithFilter) pojo).getIntValue();
+                    if (intValue >= 0) {
+                        writer.serializeAsField(pojo, jgen, provider);
+                    }
+                } else if (!jgen.canOmitFields()) { // since 2.3
+                    writer.serializeAsOmittedField(pojo, jgen, provider);
+                }
+            }
+
+            @Override
+            protected final boolean include(final BeanPropertyWriter writer) {
+                return true;
+            }
+
+            @Override
+            protected final boolean include(final PropertyWriter writer) {
+                return true;
+            }
+        };
+        final FilterProvider filters = new SimpleFilterProvider().addFilter("myFilter", theFilter);
+
+        final MyDtoWithFilter dtoObject = new MyDtoWithFilter();
+        dtoObject.setIntValue(-1);
+
+        final ObjectMapper mapper = new ObjectMapper();
+        final String dtoAsString = mapper.writer(filters)
+            .writeValueAsString(dtoObject);
+
+        assertThat(dtoAsString, not(containsString("intValue")));
+        assertThat(dtoAsString, containsString("booleanValue"));
+        assertThat(dtoAsString, containsString("stringValue"));
+        System.out.println(dtoAsString);
+    }
+
+}

jackson-custom-conversions/src/test/java/com/baeldung/skipfields/JacksonDynamicIgnoreUnitTest.java

@@ -0,0 +1,96 @@
+package com.baeldung.skipfields;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import java.util.Arrays;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import com.fasterxml.jackson.annotation.JsonInclude.Include;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.BeanDescription;
+import com.fasterxml.jackson.databind.JsonSerializer;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.SerializationConfig;
+import com.fasterxml.jackson.databind.module.SimpleModule;
+import com.fasterxml.jackson.databind.ser.BeanSerializerModifier;
+
+public class JacksonDynamicIgnoreUnitTest {
+
+    private ObjectMapper mapper = new ObjectMapper();
+
+    @Before
+    public void setUp() {
+        mapper.setSerializationInclusion(Include.NON_EMPTY);
+        mapper.registerModule(new SimpleModule() {
+            @Override
+            public void setupModule(final SetupContext context) {
+                super.setupModule(context);
+                context.addBeanSerializerModifier(new BeanSerializerModifier() {
+                    @Override
+                    public JsonSerializer<?> modifySerializer(final SerializationConfig config, final BeanDescription beanDesc, final JsonSerializer<?> serializer) {
+                        if (Hidable.class.isAssignableFrom(beanDesc.getBeanClass())) {
+                            return new HidableSerializer((JsonSerializer<Object>) serializer);
+                        }
+                        return serializer;
+                    }
+                });
+            }
+        });
+    }
+
+    @Test
+    public void whenNotHidden_thenCorrect() throws JsonProcessingException {
+        final Address ad = new Address("ny", "usa", false);
+        final Person person = new Person("john", ad, false);
+        final String result = mapper.writeValueAsString(person);
+
+        assertTrue(result.contains("name"));
+        assertTrue(result.contains("john"));
+        assertTrue(result.contains("address"));
+        assertTrue(result.contains("usa"));
+
+        System.out.println("Not Hidden = " + result);
+    }
+
+    @Test
+    public void whenAddressHidden_thenCorrect() throws JsonProcessingException {
+        final Address ad = new Address("ny", "usa", true);
+        final Person person = new Person("john", ad, false);
+        final String result = mapper.writeValueAsString(person);
+
+        assertTrue(result.contains("name"));
+        assertTrue(result.contains("john"));
+        assertFalse(result.contains("address"));
+        assertFalse(result.contains("usa"));
+
+        System.out.println("Address Hidden = " + result);
+    }
+
+    @Test
+    public void whenAllHidden_thenCorrect() throws JsonProcessingException {
+        final Address ad = new Address("ny", "usa", false);
+        final Person person = new Person("john", ad, true);
+        final String result = mapper.writeValueAsString(person);
+
+        assertTrue(result.length() == 0);
+
+        System.out.println("All Hidden = " + result);
+    }
+
+    @Test
+    public void whenSerializeList_thenCorrect() throws JsonProcessingException {
+        final Address ad1 = new Address("tokyo", "jp", true);
+        final Address ad2 = new Address("london", "uk", false);
+        final Address ad3 = new Address("ny", "usa", false);
+        final Person p1 = new Person("john", ad1, false);
+        final Person p2 = new Person("tom", ad2, true);
+        final Person p3 = new Person("adam", ad3, false);
+
+        final String result = mapper.writeValueAsString(Arrays.asList(p1, p2, p3));
+
+        System.out.println(result);
+    }
+}