[BAEL-19675] - Move articles out of jackson part 2

jackson-2/README.md

@@ -6,10 +6,7 @@ This module contains articles about Jackson.
 The "REST With Spring" Classes: http://bit.ly/restwithspring
 
 ### Relevant Articles: 
-- [Mapping Multiple JSON Fields to a Single Java Field](https://www.baeldung.com/json-multiple-fields-single-java-field)
-- [How to Process YAML with Jackson](https://www.baeldung.com/jackson-yaml)
 - [Working with Tree Model Nodes in Jackson](https://www.baeldung.com/jackson-json-node-tree-model)
-- [Converting JSON to CSV in Java](https://www.baeldung.com/java-converting-json-to-csv)
 - [Compare Two JSON Objects with Jackson](https://www.baeldung.com/jackson-compare-two-json-objects)
 - [Calling Default Serializer from Custom Serializer in Jackson](https://www.baeldung.com/jackson-call-default-serializer-from-custom-serializer)
 - More articles: [[<-- prev]](/../jackson)

jackson-2/pom.xml

@@ -14,20 +14,6 @@
 
     <dependencies>
 
-        <!-- YAML -->
-        <dependency>
-            <groupId>com.fasterxml.jackson.dataformat</groupId>
-            <artifactId>jackson-dataformat-yaml</artifactId>
-            <version>${jackson.version}</version>
-        </dependency>
-        
-        <!-- CSV -->
-        <dependency>
-            <groupId>com.fasterxml.jackson.dataformat</groupId>
-            <artifactId>jackson-dataformat-csv</artifactId>
-            <version>${jackson.version}</version>
-        </dependency>        
-
         <!-- Allow use of LocalDate -->
         <dependency>
             <groupId>com.fasterxml.jackson.datatype</groupId>

jackson-annotations/src/test/java/com/baeldung/jackson/ignore/JacksonSerializationIgnoreUnitTest.java

@@ -18,7 +18,6 @@ import com.baeldung.jackson.ignore.dtos.MyMixInForIgnoreType;
 import com.baeldung.jackson.ignore.dtos.MyDtoIgnoreField;
 import com.baeldung.jackson.ignore.dtos.MyDtoIgnoreFieldByName;
 import com.baeldung.jackson.ignore.dtos.MyDtoIgnoreNull;
-import com.baeldung.jackson.ignore.dtos.MyDtoNullKeySerializer;
 import com.fasterxml.jackson.annotation.JsonInclude.Include;
 import com.fasterxml.jackson.core.JsonGenerator;
 import com.fasterxml.jackson.core.JsonParseException;
@@ -191,88 +190,4 @@ public class JacksonSerializationIgnoreUnitTest {
         System.out.println(dtoAsString);
     }
 
-    // map
-
-    @Test
-    public final void givenIgnoringMapNullValue_whenWritingMapObjectWithNullValue_thenIgnored() throws JsonProcessingException {
-        final ObjectMapper mapper = new ObjectMapper();
-        // mapper.configure(SerializationFeature.WRITE_NULL_MAP_VALUES, false);
-        mapper.setSerializationInclusion(Include.NON_NULL);
-
-        final MyDto dtoObject1 = new MyDto();
-
-        final Map<String, MyDto> dtoMap = new HashMap<String, MyDto>();
-        dtoMap.put("dtoObject1", dtoObject1);
-        dtoMap.put("dtoObject2", null);
-
-        final String dtoMapAsString = mapper.writeValueAsString(dtoMap);
-
-        assertThat(dtoMapAsString, containsString("dtoObject1"));
-        assertThat(dtoMapAsString, not(containsString("dtoObject2")));
-        System.out.println(dtoMapAsString);
-    }
-
-    @Test
-    public final void givenIgnoringMapValueObjectWithNullField_whenWritingMapValueObjectWithNullField_thenIgnored() throws JsonProcessingException {
-        final ObjectMapper mapper = new ObjectMapper();
-        mapper.setSerializationInclusion(Include.NON_NULL);
-
-        final MyDto dtoObject = new MyDto();
-
-        final Map<String, MyDto> dtoMap = new HashMap<String, MyDto>();
-        dtoMap.put("dtoObject", dtoObject);
-
-        final String dtoMapAsString = mapper.writeValueAsString(dtoMap);
-
-        assertThat(dtoMapAsString, containsString("dtoObject"));
-        assertThat(dtoMapAsString, not(containsString("stringValue")));
-        System.out.println(dtoMapAsString);
-    }
-
-    @Test
-    public final void givenAllowingMapObjectWithNullKey_whenWriting_thenCorrect() throws JsonProcessingException {
-        final ObjectMapper mapper = new ObjectMapper();
-        mapper.getSerializerProvider()
-            .setNullKeySerializer(new MyDtoNullKeySerializer());
-
-        final MyDto dtoObject1 = new MyDto();
-        dtoObject1.setStringValue("dtoObjectString1");
-        final MyDto dtoObject2 = new MyDto();
-        dtoObject2.setStringValue("dtoObjectString2");
-
-        final Map<String, MyDto> dtoMap = new HashMap<String, MyDto>();
-        dtoMap.put(null, dtoObject1);
-        dtoMap.put("obj2", dtoObject2);
-
-        final String dtoMapAsString = mapper.writeValueAsString(dtoMap);
-
-        System.out.println(dtoMapAsString);
-        assertThat(dtoMapAsString, containsString("\"\""));
-        assertThat(dtoMapAsString, containsString("dtoObjectString1"));
-        assertThat(dtoMapAsString, containsString("obj2"));
-    }
-
-    @Test
-    public final void givenAllowingMapObjectOneNullKey_whenWritingMapObjectWithTwoNullKeys_thenOverride() throws JsonProcessingException {
-        final ObjectMapper mapper = new ObjectMapper();
-        mapper.getSerializerProvider()
-            .setNullKeySerializer(new MyDtoNullKeySerializer());
-
-        final MyDto dtoObject1 = new MyDto();
-        dtoObject1.setStringValue("dtoObject1String");
-
-        final MyDto dtoObject2 = new MyDto();
-        dtoObject2.setStringValue("dtoObject2String");
-
-        final Map<String, MyDto> dtoMap = new HashMap<String, MyDto>();
-        dtoMap.put(null, dtoObject1);
-        dtoMap.put(null, dtoObject2);
-
-        final String dtoMapAsString = mapper.writeValueAsString(dtoMap);
-
-        assertThat(dtoMapAsString, not(containsString("dtoObject1String")));
-        assertThat(dtoMapAsString, containsString("dtoObject2String"));
-        System.out.println(dtoMapAsString);
-    }
-
 }

jackson-conversions-2/README.md

@@ -0,0 +1,14 @@
+## Jackson Conversions
+
+This module contains articles about Jackson conversions.
+
+### Relevant Articles:
+- [Mapping a Dynamic JSON Object with Jackson](https://www.baeldung.com/jackson-mapping-dynamic-object)
+- [Jackson Unmarshalling JSON with Unknown Properties](https://www.baeldung.com/jackson-deserialize-json-unknown-properties)
+- [Ignore Null Fields with Jackson](https://www.baeldung.com/jackson-ignore-null-fields)
+- [Mapping Multiple JSON Fields to a Single Java Field](https://www.baeldung.com/json-multiple-fields-single-java-field)
+- [Convert XML to JSON Using Jackson](https://www.baeldung.com/jackson-convert-xml-json)
+- [Converting JSON to CSV in Java](https://www.baeldung.com/java-converting-json-to-csv)
+- [How to Process YAML with Jackson](https://www.baeldung.com/jackson-yaml)
+- [Jackson Streaming API](https://www.baeldung.com/jackson-streaming-api)
+- More articles: [[<-- prev]](../jackson-conversions)

jackson-conversions-2/pom.xml

@@ -0,0 +1,67 @@
+<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>jackson-conversions-2</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <name>jackson-conversions-2</name>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-java</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../parent-java</relativePath>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-databind</artifactId>
+            <version>${jackson.version}</version>
+        </dependency>
+        <!--jackson for xml -->
+        <dependency>
+            <groupId>com.fasterxml.jackson.dataformat</groupId>
+            <artifactId>jackson-dataformat-xml</artifactId>
+            <version>${jackson.version}</version>
+        </dependency>
+        <!-- YAML -->
+        <dependency>
+            <groupId>com.fasterxml.jackson.dataformat</groupId>
+            <artifactId>jackson-dataformat-yaml</artifactId>
+            <version>${jackson.version}</version>
+        </dependency>
+        <!-- Allow use of LocalDate -->
+        <dependency>
+            <groupId>com.fasterxml.jackson.datatype</groupId>
+            <artifactId>jackson-datatype-jsr310</artifactId>
+            <version>2.9.8</version>
+        </dependency>
+        <!-- CSV -->
+        <dependency>
+            <groupId>com.fasterxml.jackson.dataformat</groupId>
+            <artifactId>jackson-dataformat-csv</artifactId>
+            <version>${jackson.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${assertj.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <finalName>jackson-conversions-2</finalName>
+        <resources>
+            <resource>
+                <directory>src/main/resources</directory>
+                <filtering>true</filtering>
+            </resource>
+        </resources>
+    </build>
+
+    <properties>
+        <assertj.version>3.11.0</assertj.version>
+    </properties>
+
+</project>

jackson-conversions-2/src/main/java/com/baeldung/jackson/csv/JsonCsvConverter.java

@@ -3,8 +3,6 @@ package com.baeldung.jackson.csv;
 import java.io.File;
 import java.io.IOException;
 
-import com.baeldung.jackson.entities.OrderLine;
-import com.baeldung.jackson.mixin.OrderLineForCsv;
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.MappingIterator;
 import com.fasterxml.jackson.databind.ObjectMapper;

jackson-conversions-2/src/main/java/com/baeldung/jackson/csv/OrderLine.java

@@ -1,4 +1,4 @@
-package com.baeldung.jackson.entities;
+package com.baeldung.jackson.csv;
 
 import java.math.BigDecimal;
 

jackson-conversions-2/src/main/java/com/baeldung/jackson/csv/OrderLineForCsv.java

@@ -1,4 +1,4 @@
-package com.baeldung.jackson.mixin;
+package com.baeldung.jackson.csv;
 
 import java.math.BigDecimal;
 

jackson-conversions-2/src/main/java/com/baeldung/jackson/dynamicobject/Product.java

@@ -1,4 +1,4 @@
-package com.baeldung.jackson.deserialization.dynamicobject;
+package com.baeldung.jackson.dynamicobject;
 
 import java.util.LinkedHashMap;
 import java.util.Map;

jackson-conversions-2/src/main/java/com/baeldung/jackson/dynamicobject/ProductJsonNode.java

@@ -1,4 +1,4 @@
-package com.baeldung.jackson.deserialization.dynamicobject;
+package com.baeldung.jackson.dynamicobject;
 
 import com.fasterxml.jackson.databind.JsonNode;
 

jackson-conversions-2/src/main/java/com/baeldung/jackson/dynamicobject/ProductMap.java

@@ -1,4 +1,4 @@
-package com.baeldung.jackson.deserialization.dynamicobject;
+package com.baeldung.jackson.dynamicobject;
 
 import java.util.Map;
 

jackson-conversions-2/src/main/java/com/baeldung/jackson/multiplefields/Weather.java

@@ -1,4 +1,4 @@
-package com.baeldung.jackson.entities;
+package com.baeldung.jackson.multiplefields;
 
 import com.fasterxml.jackson.annotation.JsonAlias;
 import com.fasterxml.jackson.annotation.JsonProperty;

jackson-conversions-2/src/main/java/com/baeldung/jackson/unknownproperties/MyDto.java

@@ -0,0 +1,54 @@
+package com.baeldung.jackson.unknownproperties;
+
+public class MyDto {
+
+    private String stringValue;
+    private int intValue;
+    private boolean booleanValue;
+
+    public MyDto() {
+        super();
+    }
+
+    public MyDto(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;
+    }
+
+    //
+
+    @Override
+    public String toString() {
+        return "MyDto [stringValue=" + stringValue + ", intValue=" + intValue + ", booleanValue=" + booleanValue + "]";
+    }
+
+}

jackson-conversions-2/src/main/java/com/baeldung/jackson/unknownproperties/MyDtoIgnoreType.java

@@ -1,4 +1,4 @@
-package com.baeldung.jackson.dtos.ignore;
+package com.baeldung.jackson.unknownproperties;
 
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 

jackson-conversions-2/src/main/java/com/baeldung/jackson/unknownproperties/MyDtoIgnoreUnknown.java

@@ -1,4 +1,4 @@
-package com.baeldung.jackson.dtos.ignore;
+package com.baeldung.jackson.unknownproperties;
 
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 

jackson-conversions-2/src/main/java/com/baeldung/jackson/yaml/Order.java

@@ -1,4 +1,4 @@
-package com.baeldung.jackson.entities;
+package com.baeldung.jackson.yaml;
 
 import java.time.LocalDate;
 import java.util.ArrayList;

jackson-conversions-2/src/main/java/com/baeldung/jackson/yaml/OrderLine.java

@@ -0,0 +1,49 @@
+package com.baeldung.jackson.yaml;
+
+import java.math.BigDecimal;
+
+public class OrderLine {
+    private String item;
+    private int quantity;
+    private BigDecimal unitPrice;
+    
+    public OrderLine() {
+        
+    }
+
+    public OrderLine(String item, int quantity, BigDecimal unitPrice) {
+        super();
+        this.item = item;
+        this.quantity = quantity;
+        this.unitPrice = unitPrice;
+    }
+
+    public String getItem() {
+        return item;
+    }
+
+    public void setItem(String item) {
+        this.item = item;
+    }
+
+    public int getQuantity() {
+        return quantity;
+    }
+
+    public void setQuantity(int quantity) {
+        this.quantity = quantity;
+    }
+
+    public BigDecimal getUnitPrice() {
+        return unitPrice;
+    }
+
+    public void setUnitPrice(BigDecimal unitPrice) {
+        this.unitPrice = unitPrice;
+    }
+
+    @Override
+    public String toString() {
+        return "OrderLine [item=" + item + ", quantity=" + quantity + ", unitPrice=" + unitPrice + "]";
+    }
+}

jackson-conversions-2/src/test/java/com/baeldung/jackson/csv/CsvUnitTest.java

@@ -18,30 +18,30 @@ public class CsvUnitTest {
 
     @Test
     public void givenJsonInput_thenWriteCsv() throws JsonParseException, JsonMappingException, IOException {
-        JsonCsvConverter.JsonToCsv(new File("src/main/resources/orderLines.json"), 
-            new File("src/main/resources/csvFromJson.csv"));
+        JsonCsvConverter.JsonToCsv(new File("src/main/resources/csv/orderLines.json"),
+            new File("src/main/resources/csv/csvFromJson.csv"));
         
-        assertEquals(readFile("src/main/resources/csvFromJson.csv"),
-            readFile("src/test/resources/expectedCsvFromJson.csv"));
+        assertEquals(readFile("src/main/resources/csv/csvFromJson.csv"),
+            readFile("src/test/resources/csv/expectedCsvFromJson.csv"));
     }
     
     @Test
     public void givenCsvInput_thenWritesJson() throws JsonParseException, JsonMappingException, IOException {
-        JsonCsvConverter.csvToJson(new File("src/main/resources/orderLines.csv"), 
-            new File("src/main/resources/jsonFromCsv.json"));
+        JsonCsvConverter.csvToJson(new File("src/main/resources/csv/orderLines.csv"),
+            new File("src/main/resources/csv/jsonFromCsv.json"));
         
-        assertEquals(readFile("src/main/resources/jsonFromCsv.json"),
-            readFile("src/test/resources/expectedJsonFromCsv.json"));
+        assertEquals(readFile("src/main/resources/csv/jsonFromCsv.json"),
+            readFile("src/test/resources/csv/expectedJsonFromCsv.json"));
         
     }
     
     @Test
     public void givenJsonInput_thenWriteFormattedCsvOutput() throws JsonParseException, JsonMappingException, IOException {
-        JsonCsvConverter.JsonToFormattedCsv(new File("src/main/resources/orderLines.json"), 
-            new File("src/main/resources/formattedCsvFromJson.csv"));
+        JsonCsvConverter.JsonToFormattedCsv(new File("src/main/resources/csv/orderLines.json"),
+            new File("src/main/resources/csv/formattedCsvFromJson.csv"));
 
-        assertEquals(readFile("src/main/resources/formattedCsvFromJson.csv"),
-            readFile("src/test/resources/expectedFormattedCsvFromJson.csv"));
+        assertEquals(readFile("src/main/resources/csv/formattedCsvFromJson.csv"),
+            readFile("src/test/resources/csv/expectedFormattedCsvFromJson.csv"));
         
     }
     

jackson-conversions-2/src/test/java/com/baeldung/jackson/dynamicobject/DynamicObjectDeserializationUnitTest.java

@@ -1,4 +1,4 @@
-package com.baeldung.jackson.deserialization.dynamicobject;
+package com.baeldung.jackson.dynamicobject;
 
 import static org.assertj.core.api.Assertions.assertThat;
 

jackson-conversions-2/src/test/java/com/baeldung/jackson/ignorenullfields/IgnoreNullFieldsUnitTest.java

@@ -0,0 +1,52 @@
+package com.baeldung.jackson.ignorenullfields;
+
+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 IgnoreNullFieldsUnitTest {
+
+    @Test
+    public final void givenNullsIgnoredOnClass_whenWritingObjectWithNullField_thenIgnored() throws JsonProcessingException {
+        final ObjectMapper mapper = new ObjectMapper();
+        final MyDtoIgnoreNull dtoObject = new MyDtoIgnoreNull();
+
+        final String dtoAsString = mapper.writeValueAsString(dtoObject);
+
+        assertThat(dtoAsString, containsString("intValue"));
+        assertThat(dtoAsString, containsString("booleanValue"));
+        assertThat(dtoAsString, not(containsString("stringValue")));
+        System.out.println(dtoAsString);
+    }
+
+    @Test
+    public final void givenNullsIgnoredGlobally_whenWritingObjectWithNullField_thenIgnored() throws JsonProcessingException {
+        final ObjectMapper mapper = new ObjectMapper();
+        mapper.setSerializationInclusion(Include.NON_NULL);
+        final MyDto dtoObject = new MyDto();
+
+        final String dtoAsString = mapper.writeValueAsString(dtoObject);
+
+        assertThat(dtoAsString, containsString("intValue"));
+        assertThat(dtoAsString, containsString("booleanValue"));
+        assertThat(dtoAsString, not(containsString("stringValue")));
+        System.out.println(dtoAsString);
+    }
+
+}

jackson-conversions-2/src/test/java/com/baeldung/jackson/ignorenullfields/MyDto.java

@@ -0,0 +1,54 @@
+package com.baeldung.jackson.ignorenullfields;
+
+public class MyDto {
+
+    private String stringValue;
+    private int intValue;
+    private boolean booleanValue;
+
+    public MyDto() {
+        super();
+    }
+
+    public MyDto(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;
+    }
+
+    //
+
+    @Override
+    public String toString() {
+        return "MyDto [stringValue=" + stringValue + ", intValue=" + intValue + ", booleanValue=" + booleanValue + "]";
+    }
+
+}

jackson-conversions-2/src/test/java/com/baeldung/jackson/ignorenullfields/MyDtoIgnoreNull.java

@@ -0,0 +1,51 @@
+package com.baeldung.jackson.ignorenullfields;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonInclude.Include;
+
+@JsonInclude(Include.NON_NULL)
+public class MyDtoIgnoreNull {
+
+    private String stringValue;
+    private int intValue;
+    private boolean booleanValue;
+
+    public MyDtoIgnoreNull() {
+        super();
+    }
+
+    public MyDtoIgnoreNull(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-conversions-2/src/test/java/com/baeldung/jackson/multiplefields/MapMultipleFieldsToSingleFieldUnitTest.java

@@ -1,13 +1,12 @@
-package com.baeldung.jackson.deserialization.jsonalias;
+package com.baeldung.jackson.multiplefields;
 
 import static org.junit.Assert.assertEquals;
 
 import org.junit.Test;
 
-import com.baeldung.jackson.entities.Weather;
 import com.fasterxml.jackson.databind.ObjectMapper;
 
-public class JsonAliasUnitTest {
+public class MapMultipleFieldsToSingleFieldUnitTest {
 
     @Test
     public void givenTwoJsonFormats_whenDeserialized_thenWeatherObjectsCreated() throws Exception {

jackson-conversions-2/src/test/java/com/baeldung/jackson/streaming/StreamingAPIUnitTest.java

@@ -13,7 +13,7 @@ import static junit.framework.Assert.assertNull;
 import static junit.framework.Assert.assertTrue;
 import static junit.framework.TestCase.assertEquals;
 
-public class JacksonStreamingAPIUnitTest {
+public class StreamingAPIUnitTest {
 
     @Test
     public void givenJsonGenerator_whenAppendJsonToIt_thenGenerateJson() throws IOException {

jackson-conversions-2/src/test/java/com/baeldung/jackson/unknownproperties/UnknownPropertiesUnitTest.java

@@ -0,0 +1,80 @@
+package com.baeldung.jackson.unknownproperties;
+
+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.exc.UnrecognizedPropertyException;
+import org.junit.Test;
+
+import java.io.IOException;
+
+import static org.hamcrest.Matchers.equalTo;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertThat;
+
+public class UnknownPropertiesUnitTest {
+
+    @Test
+    public final void givenNotAllFieldsHaveValuesInJson_whenDeserializingAJsonToAClass_thenCorrect() throws JsonParseException, JsonMappingException, IOException {
+        final String jsonAsString = "{\"stringValue\":\"a\",\"booleanValue\":true}";
+        final ObjectMapper mapper = new ObjectMapper();
+
+        final MyDto readValue = mapper.readValue(jsonAsString, MyDto.class);
+
+        assertNotNull(readValue);
+        assertThat(readValue.getStringValue(), equalTo("a"));
+        assertThat(readValue.isBooleanValue(), equalTo(true));
+    }
+
+    // tests - json with unknown fields
+
+    @Test(expected = UnrecognizedPropertyException.class)
+    public final void givenJsonHasUnknownValues_whenDeserializingAJsonToAClass_thenExceptionIsThrown() throws JsonParseException, JsonMappingException, IOException {
+        final String jsonAsString = "{\"stringValue\":\"a\",\"intValue\":1,\"booleanValue\":true,\"stringValue2\":\"something\"}";
+        final ObjectMapper mapper = new ObjectMapper();
+
+        final MyDto readValue = mapper.readValue(jsonAsString, MyDto.class);
+
+        assertNotNull(readValue);
+        assertThat(readValue.getStringValue(), equalTo("a"));
+        assertThat(readValue.isBooleanValue(), equalTo(true));
+        assertThat(readValue.getIntValue(), equalTo(1));
+    }
+
+    @Test
+    public final void givenJsonHasUnknownValuesButJacksonIsIgnoringUnknownFields_whenDeserializing_thenCorrect() throws JsonParseException, JsonMappingException, IOException {
+        final String jsonAsString = // @formatter:off
+                "{\"stringValue\":\"a\"," +
+                "\"intValue\":1," +
+                "\"booleanValue\":true," +
+                "\"stringValue2\":\"something\"}"; // @formatter:on
+        final ObjectMapper mapper = new ObjectMapper();
+        mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
+
+        final MyDto readValue = mapper.readValue(jsonAsString, MyDto.class);
+
+        assertNotNull(readValue);
+        assertThat(readValue.getStringValue(), equalTo("a"));
+        assertThat(readValue.isBooleanValue(), equalTo(true));
+        assertThat(readValue.getIntValue(), equalTo(1));
+    }
+
+    @Test
+    public final void givenJsonHasUnknownValuesButUnknownFieldsAreIgnoredOnClass_whenDeserializing_thenCorrect() throws JsonParseException, JsonMappingException, IOException {
+        final String jsonAsString = // @formatter:off
+                "{\"stringValue\":\"a\"," +
+                "\"intValue\":1," +
+                "\"booleanValue\":true," +
+                "\"stringValue2\":\"something\"}"; // @formatter:on
+        final ObjectMapper mapper = new ObjectMapper();
+
+        final MyDtoIgnoreUnknown readValue = mapper.readValue(jsonAsString, MyDtoIgnoreUnknown.class);
+
+        assertNotNull(readValue);
+        assertThat(readValue.getStringValue(), equalTo("a"));
+        assertThat(readValue.isBooleanValue(), equalTo(true));
+        assertThat(readValue.getIntValue(), equalTo(1));
+    }
+
+}

jackson-conversions-2/src/test/java/com/baeldung/jackson/yaml/YamlUnitTest.java

@@ -15,8 +15,6 @@ import java.util.List;
 import org.junit.Before;
 import org.junit.Test;
 
-import com.baeldung.jackson.entities.Order;
-import com.baeldung.jackson.entities.OrderLine;
 import com.fasterxml.jackson.core.JsonGenerationException;
 import com.fasterxml.jackson.core.JsonParseException;
 import com.fasterxml.jackson.databind.JsonMappingException;
@@ -37,7 +35,7 @@ public class YamlUnitTest {
 
     @Test
     public void givenYamlInput_ObjectCreated() throws JsonParseException, JsonMappingException, IOException {
-        Order order = mapper.readValue(new File("src/main/resources/orderInput.yaml"), Order.class);
+        Order order = mapper.readValue(new File("src/test/resources/yaml/orderInput.yaml"), Order.class);
         assertEquals("A001", order.getOrderNo());
         assertEquals(LocalDate.parse("2019-04-17", DateTimeFormatter.ISO_DATE), order.getDate());
         assertEquals("Customer, Joe", order.getCustomerName());
@@ -55,9 +53,9 @@ public class YamlUnitTest {
             LocalDate.parse("2019-04-18", DateTimeFormatter.ISO_DATE), 
             "Customer, Jane", 
             lines);
-        mapper.writeValue(new File("src/main/resources/orderOutput.yaml"), order);
+        mapper.writeValue(new File("src/test/resources/yaml/orderOutput.yaml"), order);
 
-        File outputYaml = new File("src/main/resources/orderOutput.yaml");
+        File outputYaml = new File("src/test/resources/yaml/orderOutput.yaml");
         assertTrue(outputYaml.exists());
     }
 }

jackson-conversions/README.md

@@ -0,0 +1,16 @@
+## Jackson Conversions
+
+This module contains articles about Jackson conversions.
+
+### Relevant Articles:
+- [Jackson – Unmarshall to Collection/Array](https://www.baeldung.com/jackson-collection-array)
+- [Jackson Date](https://www.baeldung.com/jackson-serialize-dates)
+- [Jackson – Working with Maps and Nulls](https://www.baeldung.com/jackson-map-null-values-or-null-key)
+- [Jackson – Decide What Fields Get Serialized/Deserialized](https://www.baeldung.com/jackson-field-serializable-deserializable-or-not)
+- [XML Serialization and Deserialization with Jackson](https://www.baeldung.com/jackson-xml-serialization-and-deserialization)
+- [Map Serialization and Deserialization with Jackson](https://www.baeldung.com/jackson-map)
+- [How to Serialize and Deserialize Enums with Jackson](https://www.baeldung.com/jackson-serialize-enums)
+- [Jackson – Marshall String to JsonNode](https://www.baeldung.com/jackson-json-to-jsonnode)
+- [Mapping Nested Values with Jackson](https://www.baeldung.com/jackson-nested-values)
+- [Deserialize Immutable Objects with Jackson](https://www.baeldung.com/jackson-deserialize-immutable-objects)
+- More articles: [[next -->]](../jackson-conversions-2)

jackson-conversions/pom.xml

@@ -0,0 +1,49 @@
+<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>jackson-conversions</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <name>jackson-conversions</name>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-java</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../parent-java</relativePath>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-databind</artifactId>
+            <version>${jackson.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.datatype</groupId>
+            <artifactId>jackson-datatype-joda</artifactId>
+            <version>${jackson.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.datatype</groupId>
+            <artifactId>jackson-datatype-jsr310</artifactId>
+            <version>${jackson.version}</version>
+        </dependency>
+        <!--jackson for xml -->
+        <dependency>
+            <groupId>com.fasterxml.jackson.dataformat</groupId>
+            <artifactId>jackson-dataformat-xml</artifactId>
+            <version>${jackson.version}</version>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <finalName>jackson-conversions</finalName>
+        <resources>
+            <resource>
+                <directory>src/main/resources</directory>
+                <filtering>true</filtering>
+            </resource>
+        </resources>
+    </build>
+
+</project>

jackson-conversions/src/main/java/com/baeldung/jackson/enums/deserialization/City.java

@@ -1,4 +1,4 @@
-package com.baeldung.jackson.deserialization.enums;
+package com.baeldung.jackson.enums.deserialization;
 
 public class City {
 

jackson-conversions/src/main/java/com/baeldung/jackson/enums/deserialization/Distance.java

@@ -1,4 +1,4 @@
-package com.baeldung.jackson.deserialization.enums;
+package com.baeldung.jackson.enums.deserialization;
 
 public enum Distance {
 

jackson-conversions/src/main/java/com/baeldung/jackson/enums/deserialization/customdeserializer/City.java

@@ -1,4 +1,4 @@
-package com.baeldung.jackson.deserialization.enums.customdeserializer;
+package com.baeldung.jackson.enums.deserialization.customdeserializer;
 
 public class City {
 

jackson-conversions/src/main/java/com/baeldung/jackson/enums/deserialization/customdeserializer/CustomEnumDeserializer.java

@@ -1,4 +1,4 @@
-package com.baeldung.jackson.deserialization.enums.customdeserializer;
+package com.baeldung.jackson.enums.deserialization.customdeserializer;
 
 import java.io.IOException;
 import com.fasterxml.jackson.core.JsonParser;

jackson-conversions/src/main/java/com/baeldung/jackson/enums/deserialization/customdeserializer/Distance.java

@@ -1,4 +1,4 @@
-package com.baeldung.jackson.deserialization.enums.customdeserializer;
+package com.baeldung.jackson.enums.deserialization.customdeserializer;
 
 import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
 

jackson-conversions/src/main/java/com/baeldung/jackson/enums/deserialization/jsoncreator/City.java

@@ -1,4 +1,4 @@
-package com.baeldung.jackson.deserialization.enums.jsoncreator;
+package com.baeldung.jackson.enums.deserialization.jsoncreator;
 
 public class City {
 

jackson-conversions/src/main/java/com/baeldung/jackson/enums/deserialization/jsoncreator/Distance.java

@@ -1,4 +1,4 @@
-package com.baeldung.jackson.deserialization.enums.jsoncreator;
+package com.baeldung.jackson.enums.deserialization.jsoncreator;
 
 import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonProperty;

jackson-conversions/src/main/java/com/baeldung/jackson/enums/deserialization/jsonproperty/City.java

@@ -1,4 +1,4 @@
-package com.baeldung.jackson.deserialization.enums.jsonproperty;
+package com.baeldung.jackson.enums.deserialization.jsonproperty;
 
 public class City {
     

jackson-conversions/src/main/java/com/baeldung/jackson/enums/deserialization/jsonproperty/Distance.java

@@ -1,4 +1,4 @@
-package com.baeldung.jackson.deserialization.enums.jsonproperty;
+package com.baeldung.jackson.enums.deserialization.jsonproperty;
 
 import com.fasterxml.jackson.annotation.JsonProperty;
 

jackson-conversions/src/main/java/com/baeldung/jackson/enums/deserialization/jsonvalue/City.java

@@ -1,4 +1,4 @@
-package com.baeldung.jackson.deserialization.enums.jsonvalue;
+package com.baeldung.jackson.enums.deserialization.jsonvalue;
 
 public class City {
     

jackson-conversions/src/main/java/com/baeldung/jackson/enums/deserialization/jsonvalue/Distance.java

@@ -1,4 +1,4 @@
-package com.baeldung.jackson.deserialization.enums.jsonvalue;
+package com.baeldung.jackson.enums.deserialization.jsonvalue;
 
 import com.fasterxml.jackson.annotation.JsonValue;
 

jackson-conversions/src/main/java/com/baeldung/jackson/enums/serialization/Distance.java

@@ -1,6 +1,6 @@
-package com.baeldung.jackson.enums;
+package com.baeldung.jackson.enums.serialization;
 
-import com.baeldung.jackson.serialization.DistanceSerializer;
+import com.baeldung.jackson.enums.serialization.DistanceSerializer;
 import com.fasterxml.jackson.databind.annotation.JsonSerialize;
 
 /**

jackson-conversions/src/main/java/com/baeldung/jackson/enums/serialization/DistanceSerializer.java

@@ -1,8 +1,7 @@
-package com.baeldung.jackson.serialization;
+package com.baeldung.jackson.enums.serialization;
 
 import java.io.IOException;
 
-import com.baeldung.jackson.enums.Distance;
 import com.fasterxml.jackson.core.JsonGenerator;
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.SerializerProvider;

jackson-conversions/src/main/java/com/baeldung/jackson/enums/withEnum/DistanceEnumSimple.java

@@ -1,4 +1,4 @@
-package com.baeldung.jackson.dtos.withEnum;
+package com.baeldung.jackson.enums.withEnum;
 
 public enum DistanceEnumSimple {
     KILOMETER("km", 1000), MILE("miles", 1609.34), METER("meters", 1), INCH("inches", 0.0254), CENTIMETER("cm", 0.01), MILLIMETER("mm", 0.001);

jackson-conversions/src/main/java/com/baeldung/jackson/enums/withEnum/DistanceEnumWithJsonFormat.java

@@ -1,4 +1,4 @@
-package com.baeldung.jackson.dtos.withEnum;
+package com.baeldung.jackson.enums.withEnum;
 
 import com.fasterxml.jackson.annotation.JsonFormat;
 

jackson-conversions/src/main/java/com/baeldung/jackson/enums/withEnum/DistanceEnumWithValue.java

@@ -1,4 +1,4 @@
-package com.baeldung.jackson.dtos.withEnum;
+package com.baeldung.jackson.enums.withEnum;
 
 import com.fasterxml.jackson.annotation.JsonValue;
 

jackson-conversions/src/main/java/com/baeldung/jackson/enums/withEnum/MyDtoWithEnumCustom.java

@@ -1,6 +1,6 @@
-package com.baeldung.jackson.dtos.withEnum;
+package com.baeldung.jackson.enums.withEnum;
 
-import com.baeldung.jackson.enums.Distance;
+import com.baeldung.jackson.enums.serialization.Distance;
 
 public class MyDtoWithEnumCustom {
 

jackson-conversions/src/main/java/com/baeldung/jackson/enums/withEnum/MyDtoWithEnumJsonFormat.java

@@ -1,4 +1,4 @@
-package com.baeldung.jackson.dtos.withEnum;
+package com.baeldung.jackson.enums.withEnum;
 
 public class MyDtoWithEnumJsonFormat {
 

jackson-conversions/src/main/java/com/baeldung/jackson/immutable/Employee.java

@@ -1,4 +1,4 @@
-package com.baeldung.jackson.deserialization.immutable;
+package com.baeldung.jackson.immutable;
 
 import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonProperty;

jackson-conversions/src/main/java/com/baeldung/jackson/immutable/Person.java

@@ -1,4 +1,4 @@
-package com.baeldung.jackson.deserialization.immutable;
+package com.baeldung.jackson.immutable;
 
 import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
 import com.fasterxml.jackson.databind.annotation.JsonPOJOBuilder;

jackson-conversions/src/main/java/com/baeldung/jackson/map/ClassWithAMap.java

@@ -1,8 +1,7 @@
-package com.baeldung.jackson.entities;
+package com.baeldung.jackson.map;
 
 import java.util.Map;
 
-import com.baeldung.jackson.serialization.MyPairDeserializer;
 import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.databind.annotation.JsonDeserialize;

jackson-conversions/src/main/java/com/baeldung/jackson/map/MyPair.java

@@ -1,4 +1,4 @@
-package com.baeldung.jackson.entities;
+package com.baeldung.jackson.map;
 
 import com.fasterxml.jackson.annotation.JsonValue;
 

jackson-conversions/src/main/java/com/baeldung/jackson/map/MyPairDeserializer.java

@@ -1,8 +1,7 @@
-package com.baeldung.jackson.serialization;
+package com.baeldung.jackson.map;
 
 import java.io.IOException;
 
-import com.baeldung.jackson.entities.MyPair;
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.DeserializationContext;
 import com.fasterxml.jackson.databind.KeyDeserializer;

jackson-conversions/src/main/java/com/baeldung/jackson/map/MyPairSerializer.java

@@ -1,9 +1,8 @@
-package com.baeldung.jackson.serialization;
+package com.baeldung.jackson.map;
 
 import java.io.IOException;
 import java.io.StringWriter;
 
-import com.baeldung.jackson.entities.MyPair;
 import com.fasterxml.jackson.core.JsonGenerator;
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.JsonSerializer;

jackson-conversions/src/main/java/com/baeldung/jackson/mapnull/MyDto.java

@@ -0,0 +1,54 @@
+package com.baeldung.jackson.mapnull;
+
+public class MyDto {
+
+    private String stringValue;
+    private int intValue;
+    private boolean booleanValue;
+
+    public MyDto() {
+        super();
+    }
+
+    public MyDto(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;
+    }
+
+    //
+
+    @Override
+    public String toString() {
+        return "MyDto [stringValue=" + stringValue + ", intValue=" + intValue + ", booleanValue=" + booleanValue + "]";
+    }
+
+}

jackson-conversions/src/main/java/com/baeldung/jackson/mapnull/MyDtoNullKeySerializer.java

@@ -1,4 +1,4 @@
-package com.baeldung.jackson.ignore.dtos;
+package com.baeldung.jackson.mapnull;
 
 import java.io.IOException;
 

jackson-conversions/src/main/java/com/baeldung/jackson/tocollection/MyDto.java

@@ -0,0 +1,54 @@
+package com.baeldung.jackson.tocollection;
+
+public class MyDto {
+
+    private String stringValue;
+    private int intValue;
+    private boolean booleanValue;
+
+    public MyDto() {
+        super();
+    }
+
+    public MyDto(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;
+    }
+
+    //
+
+    @Override
+    public String toString() {
+        return "MyDto [stringValue=" + stringValue + ", intValue=" + intValue + ", booleanValue=" + booleanValue + "]";
+    }
+
+}

jackson-conversions/src/main/java/com/baeldung/jackson/xml/Address.java

@@ -0,0 +1,33 @@
+package com.baeldung.jackson.xml;
+
+public class Address {
+
+    String streetNumber;
+    String streetName;
+    String city;
+
+    public String getStreetNumber() {
+        return streetNumber;
+    }
+
+    public void setStreetNumber(String streetNumber) {
+        this.streetNumber = streetNumber;
+    }
+
+    public String getStreetName() {
+        return streetName;
+    }
+
+    public void setStreetName(String streetName) {
+        this.streetName = streetName;
+    }
+
+    public String getCity() {
+        return city;
+    }
+
+    public void setCity(String city) {
+        this.city = city;
+    }
+
+}

jackson-conversions/src/main/java/com/baeldung/jackson/xml/Person.java

@@ -0,0 +1,47 @@
+package com.baeldung.jackson.xml;
+
+import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlRootElement;
+
+import java.util.ArrayList;
+import java.util.List;
+
+@JacksonXmlRootElement(localName = "person")
+public final class Person {
+    private String firstName;
+    private String lastName;
+    private List<String> phoneNumbers = new ArrayList<>();
+    private List<Address> address = new ArrayList<>();
+
+    public List<Address> getAddress() {
+        return address;
+    }
+
+    public void setAddress(List<Address> address) {
+        this.address = address;
+    }
+
+    public String getFirstName() {
+        return firstName;
+    }
+
+    public void setFirstName(String firstName) {
+        this.firstName = firstName;
+    }
+
+    public String getLastName() {
+        return lastName;
+    }
+
+    public void setLastName(String lastName) {
+        this.lastName = lastName;
+    }
+
+    public List<String> getPhoneNumbers() {
+        return phoneNumbers;
+    }
+
+    public void setPhoneNumbers(List<String> phoneNumbers) {
+        this.phoneNumbers = phoneNumbers;
+    }
+
+}

jackson-conversions/src/test/java/com/baeldung/jackson/date/JacksonDateUnitTest.java

@@ -1,4 +1,4 @@
-package com.baeldung.jackson.test;
+package com.baeldung.jackson.date;
 
 import static org.hamcrest.Matchers.containsString;
 import static org.junit.Assert.assertEquals;

jackson-conversions/src/test/java/com/baeldung/jackson/enums/deserialization/DefaultEnumDeserializationUnitTest.java

@@ -1,7 +1,8 @@
-package com.baeldung.jackson.deserialization.enums;
+package com.baeldung.jackson.enums.deserialization;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import java.io.IOException;
+
 import org.junit.Test;
 import com.fasterxml.jackson.core.JsonParseException;
 import com.fasterxml.jackson.databind.ObjectMapper;

jackson-conversions/src/test/java/com/baeldung/jackson/enums/deserialization/customdeserializer/EnumCustomDeserializationUnitTest.java

@@ -1,7 +1,8 @@
-package com.baeldung.jackson.deserialization.enums.customdeserializer;
+package com.baeldung.jackson.enums.deserialization.customdeserializer;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import java.io.IOException;
+
 import org.junit.Test;
 import com.fasterxml.jackson.core.JsonParseException;
 import com.fasterxml.jackson.databind.ObjectMapper;

jackson-conversions/src/test/java/com/baeldung/jackson/enums/deserialization/jsoncreator/EnumDeserializationUsingJsonCreatorUnitTest.java

@@ -1,7 +1,8 @@
-package com.baeldung.jackson.deserialization.enums.jsoncreator;
+package com.baeldung.jackson.enums.deserialization.jsoncreator;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import java.io.IOException;
+
 import org.junit.Test;
 import com.fasterxml.jackson.core.JsonParseException;
 import com.fasterxml.jackson.databind.ObjectMapper;

jackson-conversions/src/test/java/com/baeldung/jackson/enums/deserialization/jsonproperty/EnumDeserializationUsingJsonPropertyUnitTest.java

@@ -1,7 +1,8 @@
-package com.baeldung.jackson.deserialization.enums.jsonproperty;
+package com.baeldung.jackson.enums.deserialization.jsonproperty;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import java.io.IOException;
+
 import org.junit.Test;
 import com.fasterxml.jackson.core.JsonParseException;
 import com.fasterxml.jackson.databind.ObjectMapper;

jackson-conversions/src/test/java/com/baeldung/jackson/enums/deserialization/jsonvalue/EnumDeserializationUsingJsonValueUnitTest.java

@@ -1,7 +1,8 @@
-package com.baeldung.jackson.deserialization.enums.jsonvalue;
+package com.baeldung.jackson.enums.deserialization.jsonvalue;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import java.io.IOException;
+
 import org.junit.Test;
 import com.fasterxml.jackson.core.JsonParseException;
 import com.fasterxml.jackson.databind.ObjectMapper;

jackson-conversions/src/test/java/com/baeldung/jackson/enums/serialization/JacksonEnumSerializationUnitTest.java

@@ -1,8 +1,9 @@
-package com.baeldung.jackson.enums;
+package com.baeldung.jackson.enums.serialization;
 
 import static org.hamcrest.Matchers.containsString;
 import static org.junit.Assert.assertThat;
 import java.io.IOException;
+
 import org.junit.Test;
 import com.fasterxml.jackson.core.JsonParseException;
 import com.fasterxml.jackson.databind.ObjectMapper;

jackson-conversions/src/test/java/com/baeldung/jackson/enums/serialization/JacksonSerializationEnumsUnitTest.java

@@ -1,4 +1,4 @@
-package com.baeldung.jackson.test;
+package com.baeldung.jackson.enums.serialization;
 
 import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.is;
@@ -8,12 +8,12 @@ import java.io.IOException;
 
 import org.junit.Test;
 
-import com.baeldung.jackson.dtos.withEnum.DistanceEnumSimple;
-import com.baeldung.jackson.dtos.withEnum.DistanceEnumWithJsonFormat;
-import com.baeldung.jackson.dtos.withEnum.DistanceEnumWithValue;
-import com.baeldung.jackson.dtos.withEnum.MyDtoWithEnumCustom;
-import com.baeldung.jackson.dtos.withEnum.MyDtoWithEnumJsonFormat;
-import com.baeldung.jackson.enums.Distance;
+import com.baeldung.jackson.enums.withEnum.DistanceEnumSimple;
+import com.baeldung.jackson.enums.withEnum.DistanceEnumWithJsonFormat;
+import com.baeldung.jackson.enums.withEnum.DistanceEnumWithValue;
+import com.baeldung.jackson.enums.withEnum.MyDtoWithEnumCustom;
+import com.baeldung.jackson.enums.withEnum.MyDtoWithEnumJsonFormat;
+import com.baeldung.jackson.enums.serialization.Distance;
 import com.fasterxml.jackson.core.JsonParseException;
 import com.fasterxml.jackson.databind.ObjectMapper;
 

jackson-conversions/src/test/java/com/baeldung/jackson/field/JacksonFieldUnitTest.java

@@ -1,4 +1,4 @@
-package com.baeldung.jackson.test;
+package com.baeldung.jackson.field;
 
 import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.equalTo;
@@ -7,10 +7,6 @@ import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertThat;
 
 import java.io.IOException;
-
-import com.baeldung.jackson.field.MyDtoAccessLevel;
-import com.baeldung.jackson.field.MyDtoWithSetter;
-import com.baeldung.jackson.field.MyDtoWithGetter;
 import org.junit.Test;
 
 import com.fasterxml.jackson.annotation.JsonAutoDetect.Visibility;

jackson-conversions/src/test/java/com/baeldung/jackson/immutable/ImmutableObjectDeserializationUnitTest.java

@@ -1,4 +1,4 @@
-package com.baeldung.jackson.deserialization.immutable;
+package com.baeldung.jackson.immutable;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
 import org.junit.Test;

jackson-conversions/src/test/java/com/baeldung/jackson/map/JacksonMapDeserializeUnitTest.java

@@ -1,4 +1,4 @@
-package com.baeldung.jackson.deserialization;
+package com.baeldung.jackson.map;
 
 import java.io.IOException;
 import java.util.HashMap;
@@ -7,8 +7,6 @@ import java.util.Map;
 import org.junit.Assert;
 import org.junit.Test;
 
-import com.baeldung.jackson.entities.ClassWithAMap;
-import com.baeldung.jackson.entities.MyPair;
 import com.fasterxml.jackson.core.JsonParseException;
 import com.fasterxml.jackson.core.type.TypeReference;
 import com.fasterxml.jackson.databind.JsonMappingException;

jackson-conversions/src/test/java/com/baeldung/jackson/map/JacksonMapSerializeUnitTest.java

@@ -1,4 +1,4 @@
-package com.baeldung.jackson.serialization;
+package com.baeldung.jackson.map;
 
 import java.util.HashMap;
 import java.util.Map;
@@ -6,7 +6,6 @@ import java.util.Map;
 import org.junit.Assert;
 import org.junit.Test;
 
-import com.baeldung.jackson.entities.MyPair;
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.annotation.JsonSerialize;

jackson-conversions/src/test/java/com/baeldung/jackson/mapnull/JacksonMapNullUnitTest.java

@@ -0,0 +1,109 @@
+package com.baeldung.jackson.mapnull;
+
+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 java.util.HashMap;
+import java.util.Map;
+
+import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.not;
+import static org.junit.Assert.assertThat;
+
+public class JacksonMapNullUnitTest {
+
+    @Test
+    public final void givenIgnoringMapNullValue_whenWritingMapObjectWithNullValue_thenIgnored() throws JsonProcessingException {
+        final ObjectMapper mapper = new ObjectMapper();
+        // mapper.configure(SerializationFeature.WRITE_NULL_MAP_VALUES, false);
+        mapper.setSerializationInclusion(Include.NON_NULL);
+
+        final MyDto dtoObject1 = new MyDto();
+
+        final Map<String, MyDto> dtoMap = new HashMap<String, MyDto>();
+        dtoMap.put("dtoObject1", dtoObject1);
+        dtoMap.put("dtoObject2", null);
+
+        final String dtoMapAsString = mapper.writeValueAsString(dtoMap);
+
+        assertThat(dtoMapAsString, containsString("dtoObject1"));
+        assertThat(dtoMapAsString, not(containsString("dtoObject2")));
+        System.out.println(dtoMapAsString);
+    }
+
+    @Test
+    public final void givenIgnoringMapValueObjectWithNullField_whenWritingMapValueObjectWithNullField_thenIgnored() throws JsonProcessingException {
+        final ObjectMapper mapper = new ObjectMapper();
+        mapper.setSerializationInclusion(Include.NON_NULL);
+
+        final MyDto dtoObject = new MyDto();
+
+        final Map<String, MyDto> dtoMap = new HashMap<String, MyDto>();
+        dtoMap.put("dtoObject", dtoObject);
+
+        final String dtoMapAsString = mapper.writeValueAsString(dtoMap);
+
+        assertThat(dtoMapAsString, containsString("dtoObject"));
+        assertThat(dtoMapAsString, not(containsString("stringValue")));
+        System.out.println(dtoMapAsString);
+    }
+
+    @Test
+    public final void givenAllowingMapObjectWithNullKey_whenWriting_thenCorrect() throws JsonProcessingException {
+        final ObjectMapper mapper = new ObjectMapper();
+        mapper.getSerializerProvider()
+            .setNullKeySerializer(new MyDtoNullKeySerializer());
+
+        final MyDto dtoObject1 = new MyDto();
+        dtoObject1.setStringValue("dtoObjectString1");
+        final MyDto dtoObject2 = new MyDto();
+        dtoObject2.setStringValue("dtoObjectString2");
+
+        final Map<String, MyDto> dtoMap = new HashMap<String, MyDto>();
+        dtoMap.put(null, dtoObject1);
+        dtoMap.put("obj2", dtoObject2);
+
+        final String dtoMapAsString = mapper.writeValueAsString(dtoMap);
+
+        System.out.println(dtoMapAsString);
+        assertThat(dtoMapAsString, containsString("\"\""));
+        assertThat(dtoMapAsString, containsString("dtoObjectString1"));
+        assertThat(dtoMapAsString, containsString("obj2"));
+    }
+
+    @Test
+    public final void givenAllowingMapObjectOneNullKey_whenWritingMapObjectWithTwoNullKeys_thenOverride() throws JsonProcessingException {
+        final ObjectMapper mapper = new ObjectMapper();
+        mapper.getSerializerProvider()
+            .setNullKeySerializer(new MyDtoNullKeySerializer());
+
+        final MyDto dtoObject1 = new MyDto();
+        dtoObject1.setStringValue("dtoObject1String");
+
+        final MyDto dtoObject2 = new MyDto();
+        dtoObject2.setStringValue("dtoObject2String");
+
+        final Map<String, MyDto> dtoMap = new HashMap<String, MyDto>();
+        dtoMap.put(null, dtoObject1);
+        dtoMap.put(null, dtoObject2);
+
+        final String dtoMapAsString = mapper.writeValueAsString(dtoMap);
+
+        assertThat(dtoMapAsString, not(containsString("dtoObject1String")));
+        assertThat(dtoMapAsString, containsString("dtoObject2String"));
+        System.out.println(dtoMapAsString);
+    }
+
+}

jackson-conversions/src/test/java/com/baeldung/jackson/nested/DeserializeWithNestedPropertiesUnitTest.java

@@ -1,70 +1,70 @@
-package com.baeldung.jackson.deserialization.nested;
-
-import static org.junit.Assert.*;
-
-import java.io.IOException;
-
-import org.junit.Test;
-
-import com.fasterxml.jackson.databind.JsonNode;
-import com.fasterxml.jackson.databind.ObjectMapper;
-import com.fasterxml.jackson.databind.module.SimpleModule;
-
-public class DeserializeWithNestedPropertiesUnitTest {
-
-    private String SOURCE_JSON = "{\"id\":\"957c43f2-fa2e-42f9-bf75-6e3d5bb6960a\",\"name\":\"The Best Product\",\"brand\":{\"id\":\"9bcd817d-0141-42e6-8f04-e5aaab0980b6\",\"name\":\"ACME Products\",\"owner\":{\"id\":\"b21a80b1-0c09-4be3-9ebd-ea3653511c13\",\"name\":\"Ultimate Corp, Inc.\"}}}";
-
-    @Test
-    public void whenUsingAnnotations_thenOk() throws IOException {
-        Product product = new ObjectMapper().readerFor(Product.class)
-            .readValue(SOURCE_JSON);
-
-        assertEquals(product.getName(), "The Best Product");
-        assertEquals(product.getBrandName(), "ACME Products");
-        assertEquals(product.getOwnerName(), "Ultimate Corp, Inc.");
-    }
-
-    @Test
-    public void whenUsingJsonNode_thenOk() throws IOException {
-        JsonNode productNode = new ObjectMapper().readTree(SOURCE_JSON);
-
-        Product product = new Product();
-        product.setId(productNode.get("id")
-            .textValue());
-        product.setName(productNode.get("name")
-            .textValue());
-        product.setBrandName(productNode.get("brand")
-            .get("name")
-            .textValue());
-        product.setOwnerName(productNode.get("brand")
-            .get("owner")
-            .get("name")
-            .textValue());
-
-        assertEquals(product.getName(), "The Best Product");
-        assertEquals(product.getBrandName(), "ACME Products");
-        assertEquals(product.getOwnerName(), "Ultimate Corp, Inc.");
-    }
-
-    @Test
-    public void whenUsingDeserializerManuallyRegistered_thenOk() throws IOException {
-        ObjectMapper mapper = new ObjectMapper();
-        SimpleModule module = new SimpleModule();
-        module.addDeserializer(Product.class, new ProductDeserializer());
-        mapper.registerModule(module);
-
-        Product product = mapper.readValue(SOURCE_JSON, Product.class);
-        assertEquals(product.getName(), "The Best Product");
-        assertEquals(product.getBrandName(), "ACME Products");
-        assertEquals(product.getOwnerName(), "Ultimate Corp, Inc.");
-    }
-
-    @Test
-    public void whenUsingDeserializerAutoRegistered_thenOk() throws IOException {
-        ObjectMapper mapper = new ObjectMapper();
-        Product product = mapper.readValue(SOURCE_JSON, Product.class);
-        assertEquals(product.getName(), "The Best Product");
-        assertEquals(product.getBrandName(), "ACME Products");
-        assertEquals(product.getOwnerName(), "Ultimate Corp, Inc.");
-    }
-}
+package com.baeldung.jackson.nested;
+
+import static org.junit.Assert.*;
+
+import java.io.IOException;
+
+import org.junit.Test;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.module.SimpleModule;
+
+public class DeserializeWithNestedPropertiesUnitTest {
+
+    private String SOURCE_JSON = "{\"id\":\"957c43f2-fa2e-42f9-bf75-6e3d5bb6960a\",\"name\":\"The Best Product\",\"brand\":{\"id\":\"9bcd817d-0141-42e6-8f04-e5aaab0980b6\",\"name\":\"ACME Products\",\"owner\":{\"id\":\"b21a80b1-0c09-4be3-9ebd-ea3653511c13\",\"name\":\"Ultimate Corp, Inc.\"}}}";
+
+    @Test
+    public void whenUsingAnnotations_thenOk() throws IOException {
+        Product product = new ObjectMapper().readerFor(Product.class)
+            .readValue(SOURCE_JSON);
+
+        assertEquals(product.getName(), "The Best Product");
+        assertEquals(product.getBrandName(), "ACME Products");
+        assertEquals(product.getOwnerName(), "Ultimate Corp, Inc.");
+    }
+
+    @Test
+    public void whenUsingJsonNode_thenOk() throws IOException {
+        JsonNode productNode = new ObjectMapper().readTree(SOURCE_JSON);
+
+        Product product = new Product();
+        product.setId(productNode.get("id")
+            .textValue());
+        product.setName(productNode.get("name")
+            .textValue());
+        product.setBrandName(productNode.get("brand")
+            .get("name")
+            .textValue());
+        product.setOwnerName(productNode.get("brand")
+            .get("owner")
+            .get("name")
+            .textValue());
+
+        assertEquals(product.getName(), "The Best Product");
+        assertEquals(product.getBrandName(), "ACME Products");
+        assertEquals(product.getOwnerName(), "Ultimate Corp, Inc.");
+    }
+
+    @Test
+    public void whenUsingDeserializerManuallyRegistered_thenOk() throws IOException {
+        ObjectMapper mapper = new ObjectMapper();
+        SimpleModule module = new SimpleModule();
+        module.addDeserializer(Product.class, new ProductDeserializer());
+        mapper.registerModule(module);
+
+        Product product = mapper.readValue(SOURCE_JSON, Product.class);
+        assertEquals(product.getName(), "The Best Product");
+        assertEquals(product.getBrandName(), "ACME Products");
+        assertEquals(product.getOwnerName(), "Ultimate Corp, Inc.");
+    }
+
+    @Test
+    public void whenUsingDeserializerAutoRegistered_thenOk() throws IOException {
+        ObjectMapper mapper = new ObjectMapper();
+        Product product = mapper.readValue(SOURCE_JSON, Product.class);
+        assertEquals(product.getName(), "The Best Product");
+        assertEquals(product.getBrandName(), "ACME Products");
+        assertEquals(product.getOwnerName(), "Ultimate Corp, Inc.");
+    }
+}

jackson-conversions/src/test/java/com/baeldung/jackson/nested/Product.java

@@ -1,55 +1,55 @@
-package com.baeldung.jackson.deserialization.nested;
-
-import java.util.Map;
-
-import com.fasterxml.jackson.annotation.JsonProperty;
-import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
-
-@JsonDeserialize(using = ProductDeserializer.class)
-public class Product {
-
-    private String id;
-    private String name;
-    private String brandName;
-    private String ownerName;
-
-    public String getId() {
-        return id;
-    }
-
-    public void setId(String id) {
-        this.id = id;
-    }
-
-    public String getName() {
-        return name;
-    }
-
-    public void setName(String name) {
-        this.name = name;
-    }
-
-    public String getBrandName() {
-        return brandName;
-    }
-
-    public void setBrandName(String brandName) {
-        this.brandName = brandName;
-    }
-
-    public String getOwnerName() {
-        return ownerName;
-    }
-
-    public void setOwnerName(String ownerName) {
-        this.ownerName = ownerName;
-    }
-
-    @SuppressWarnings("unchecked")
-    @JsonProperty("brand")
-    private void unpackNested(Map<String, Object> brand) {
-        this.brandName = (String) brand.get("name");
-        Map<String, String> owner = (Map<String, String>) brand.get("owner");
-        this.ownerName = owner.get("name");
-    }
+package com.baeldung.jackson.nested;
+
+import java.util.Map;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+
+@JsonDeserialize(using = ProductDeserializer.class)
+public class Product {
+
+    private String id;
+    private String name;
+    private String brandName;
+    private String ownerName;
+
+    public String getId() {
+        return id;
+    }
+
+    public void setId(String id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getBrandName() {
+        return brandName;
+    }
+
+    public void setBrandName(String brandName) {
+        this.brandName = brandName;
+    }
+
+    public String getOwnerName() {
+        return ownerName;
+    }
+
+    public void setOwnerName(String ownerName) {
+        this.ownerName = ownerName;
+    }
+
+    @SuppressWarnings("unchecked")
+    @JsonProperty("brand")
+    private void unpackNested(Map<String, Object> brand) {
+        this.brandName = (String) brand.get("name");
+        Map<String, String> owner = (Map<String, String>) brand.get("owner");
+        this.ownerName = owner.get("name");
+    }
 }

jackson-conversions/src/test/java/com/baeldung/jackson/nested/ProductDeserializer.java

@@ -1,40 +1,40 @@
-package com.baeldung.jackson.deserialization.nested;
-
-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;
-
-@SuppressWarnings("serial")
-public class ProductDeserializer extends StdDeserializer<Product> {
-
-    public ProductDeserializer() {
-        this(null);
-    }
-
-    public ProductDeserializer(Class<?> vc) {
-        super(vc);
-    }
-
-    @Override
-    public Product deserialize(JsonParser jp, DeserializationContext ctxt) throws IOException, JsonProcessingException {
-        JsonNode productNode = jp.getCodec()
-            .readTree(jp);
-        Product product = new Product();
-        product.setId(productNode.get("id")
-            .textValue());
-        product.setName(productNode.get("name")
-            .textValue());
-        product.setBrandName(productNode.get("brand")
-            .get("name")
-            .textValue());
-        product.setOwnerName(productNode.get("brand")
-            .get("owner")
-            .get("name")
-            .textValue());
-        return product;
-    }
-}
+package com.baeldung.jackson.nested;
+
+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;
+
+@SuppressWarnings("serial")
+public class ProductDeserializer extends StdDeserializer<Product> {
+
+    public ProductDeserializer() {
+        this(null);
+    }
+
+    public ProductDeserializer(Class<?> vc) {
+        super(vc);
+    }
+
+    @Override
+    public Product deserialize(JsonParser jp, DeserializationContext ctxt) throws IOException, JsonProcessingException {
+        JsonNode productNode = jp.getCodec()
+            .readTree(jp);
+        Product product = new Product();
+        product.setId(productNode.get("id")
+            .textValue());
+        product.setName(productNode.get("name")
+            .textValue());
+        product.setBrandName(productNode.get("brand")
+            .get("name")
+            .textValue());
+        product.setOwnerName(productNode.get("brand")
+            .get("owner")
+            .get("name")
+            .textValue());
+        return product;
+    }
+}

jackson-conversions/src/test/java/com/baeldung/jackson/tocollection/JacksonCollectionDeserializationUnitTest.java

@@ -1,4 +1,4 @@
-package com.baeldung.jackson.test;
+package com.baeldung.jackson.tocollection;
 
 import static org.hamcrest.Matchers.instanceOf;
 import static org.junit.Assert.assertThat;
@@ -6,8 +6,6 @@ import static org.junit.Assert.assertThat;
 import java.io.IOException;
 import java.util.LinkedHashMap;
 import java.util.List;
-
-import com.baeldung.jackson.dtos.MyDto;
 import org.junit.Test;
 
 import com.fasterxml.jackson.core.JsonParseException;

jackson-conversions/src/test/java/com/baeldung/jackson/tojsonnode/StringToJsonNodeUnitTest.java

@@ -0,0 +1,51 @@
+package com.baeldung.jackson.tojsonnode;
+
+import com.fasterxml.jackson.core.JsonFactory;
+import com.fasterxml.jackson.core.JsonParseException;
+import com.fasterxml.jackson.core.JsonParser;
+import org.junit.Test;
+
+import java.io.IOException;
+
+import static org.hamcrest.Matchers.equalTo;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertThat;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+public class StringToJsonNodeUnitTest {
+
+    @Test
+    public final void whenParsingJsonStringIntoJsonNode_thenCorrect() throws JsonParseException, IOException {
+        final String jsonString = "{\"k1\":\"v1\",\"k2\":\"v2\"}";
+
+        final ObjectMapper mapper = new ObjectMapper();
+        final JsonNode actualObj = mapper.readTree(jsonString);
+
+        assertNotNull(actualObj);
+    }
+
+    @Test
+    public final void givenUsingLowLevelDetails_whenParsingJsonStringIntoJsonNode_thenCorrect() throws JsonParseException, IOException {
+        final String jsonString = "{\"k1\":\"v1\",\"k2\":\"v2\"}";
+
+        final ObjectMapper mapper = new ObjectMapper();
+        final JsonFactory factory = mapper.getFactory();
+        final JsonParser parser = factory.createParser(jsonString);
+        final JsonNode actualObj = mapper.readTree(parser);
+
+        assertNotNull(actualObj);
+    }
+
+    @Test
+    public final void givenTheJsonNode_whenRetrievingDataFromId_thenCorrect() throws JsonParseException, IOException {
+        final String jsonString = "{\"k1\":\"v1\",\"k2\":\"v2\"}";
+        final ObjectMapper mapper = new ObjectMapper();
+        final JsonNode actualObj = mapper.readTree(jsonString);
+
+        // When
+        final JsonNode jsonNode1 = actualObj.get("k1");
+        assertThat(jsonNode1.textValue(), equalTo("v1"));
+    }
+
+}

jackson-conversions/src/test/java/com/baeldung/jackson/xml/XMLSerializeDeserializeUnitTest.java

@@ -16,8 +16,6 @@ import java.util.List;
 
 import org.junit.Test;
 
-import com.baeldung.jackson.dtos.Address;
-import com.baeldung.jackson.dtos.Person;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.dataformat.xml.XmlMapper;