XML Serialization and Deserialization with Jackson

In this section, we will discuss another important concept of Jackson, i.e., serialization and deserialization of XML data. By using Jackson, we can easily serialize a Java Object into XML data or deserialize it back to a Java object (POJO). In order to work with XML, we use Jackson “2.x”.

First, we will add Jackson “2.x”, dependency in our POM.xml file:

  <dependency>  <groupId>com.fasterxml.jackson.dataformat</groupId>      <artifactId>jackson-dataformat-xml</artifactId>      <version>2.11.1</version>  </dependency>  

Note: Please add the latest version of Jackson-dataformat-xml dependency.

Let’s understand how we work with XML by using Jackson in detail.

XmlMapper Object

XmlMapper is one of the most important classes from Jackson “2.x”. It is used for the serialization and deserialization of the XML data. So, the first step for serializing and deserializing XML data is to create an instance of the XmlMapper class in the following way:

Serializing Java Object into XML

ObjectMapper is a parent class of XmlMapper that is used for serializing JSON data. If we want to make any changes to the parent class, add some XML specific changes into the parent class. Let’s understand how we can use it for serializing the following Java class:

College.java

  class College {      //Creating properties of College class      public String name;        public String university;     public String address;   public String rank;       // default constructor   College(){    }  // parameterized constructor    College(String name, String university, String address, String rank){    this.name = name;    this.university = university;    this.address = address;    this.rank = rank;    }    // getters and setters   }  

Serialize POJO to XML String

We can easily convert POJO into XML string by simply creating an instance of XmlMapper class and use its writeValueAsString() method in the following way:

Let’s take an example to understand how we can use it to serialize Java Object into an XML string.

PojoToXMLExample1.java

  //import required classes and package if any    import java.io.IOException;    import java.util.Scanner;  import com.fasterxml.jackson.dataformat.xml.XmlMapper;  //create class PojoToXMLExample1  public class PojoToXMLExample1 {    //main() methods start    public static void main(String args[]) {    // create an instance of XmlMapper class    XmlMapper xmlMap = new XmlMapper();    // create Scanner class object    Scanner sc= new Scanner(System.in);         // using try-catch  try {    College colg;    String name, university, street, state, city, rank;    System.out.println(“Enter College Name:”);    name = sc.nextLine();    System.out.println(“Enter University Name:”);    university = sc.nextLine();      System.out.println(“Enter Street:”);    street = sc.nextLine();      System.out.println(“Enter City:”);    city = sc.nextLine();    System.out.println(“Enter State:”);    state = sc.nextLine();  System.out.println(“Enter College Rank:”);    rank = sc.nextLine();    // set values to College object by using constructor    colg = new College(name, university, new Address(street, state, city), rank);  // serialize College using xmlMap    String xmlString = xmlMap  .writeValueAsString(colg);    System.out.println(xmlString);    } catch (IOException e) {     e.printStackTrace();    }    //close Scanner class object    sc.close();    }    }  //create class College  class College {        //Creating properties of College class      public String name;        public String university;     public Address address;   public String rank;       // constructor    College(String name, String university, Address address, String rank){    this.name = name;    this.university = university;    this.address = address;    this.rank = rank;    }      }  //create class Address   class Address {    public String street;  public String state;  public String city;    Address(String street, String state, String city){      this.street = street;    this.state = state;    this.city = city;  }           }  

Output:

XML Serialization and Deserialization with Jackson

Serialize POJO to XML File

In order to serialize Java object into XML File, we simply create an instance of the XmlMapper class and use its writeValue() method. In the writeValue() method, we pass two parameters, i.e., location of the XML file and instance of Java object in the following way:

  XmlMapper xmlMap = new XmlMapper();  xmlMap.writeValue(file_location, java_object)  

Let’s take an example to understand how we can use it to serialize Java Object into an XML file.

PojoToXMLExample2.java

  import java.io.File;  //import required classes and package if any    import java.io.IOException;    import java.util.Scanner;    import com.fasterxml.jackson.dataformat.xml.XmlMapper;    //create class PojoToXMLExample2  public class PojoToXMLExample2 {      //main() methods start    public static void main(String args[]) {      // create an instance of XmlMapper class    XmlMapper xmlMap = new XmlMapper();      // create Scanner class object    Scanner sc= new Scanner(System.in);           // using try-catch  try {      College colg;      String name, university, street, state, city, rank;      System.out.println(“Enter College Name:”);    name = sc.nextLine();      System.out.println(“Enter University Name:”);    university = sc.nextLine();      System.out.println(“Enter Street:”);    street = sc.nextLine();      System.out.println(“Enter City:”);    city = sc.nextLine();    System.out.println(“Enter State:”);    state = sc.nextLine();    System.out.println(“Enter College Rank:”);    rank = sc.nextLine();      // set values to College  object by using constructor    colg = new College(name, university, new Address(street, state, city), rank);    // serialize College using xmlMap    xmlMap.writeValue(new File(“C:\Users\rastogi ji\Desktop\College.xml”), colg);    System.out.println(“College object is successfully serialize into College.xml file.”);                  } catch (IOException e) {     e.printStackTrace();    }      //close Scanner class object    sc.close();      }    }  //create class College  class College {        //Creating properties of College class      public String name;        public String university;     public Address address;   public String rank;       // constructor    College(String name, String university, Address address, String rank){    this.name = name;    this.university = university;    this.address = address;    this.rank = rank;    }      }  //create class Address   class Address {    public String street;  public String state;  public String city;    Address(String street, String state, String city){      this.street = street;    this.state = state;    this.city = city;  }           }  

Output:

XML Serialization and Deserialization with Jackson

Deserializing XML into POJO

Just like serializing, we can easily deserialize XML data into POJO by using XmlMapper class. Let’s understand how we can deserialize the data from the XML String or an XML file one by one.

We deserialize the following XML into POJO by using XmlMapper:

  <College>  <name>ABES</name>  <university>AKTU</university>  <address>  NH-24 GZB UP  </address>  <rank>1</rank>  </College>  

De-serialize data from the XML String

In order to deserialize the XML string into POJO, follow the steps given below:

1. Create an instance of the XmlMapper class in the following way:

2. Use the readValue() method of the XmlMapper class and pass the XML string and name of the class in which XML string is to be deserialized.

Let’s take an example to understand how we can use it to deserialize the XML string into POJO.

XMLToPojoExample1.java

  //import required classes and package if any    import com.fasterxml.jackson.core.JsonProcessingException;  import com.fasterxml.jackson.databind.JsonMappingException;  import com.fasterxml.jackson.dataformat.xml.XmlMapper;  import com.fasterxml.jackson.annotation.JsonProperty;  //create class XMLToPojoExample1  public class XMLToPojoExample1 {    //main() methods start    public static void main(String args[]) {    // create an instance of XmlMapper class    XmlMapper xmlMap = new XmlMapper();    // xmlString  String xmlString = “ABESAKTU”  + “
<address>NH-24 Highway GZB UP</address>
<p>1″;  try {  College colg = xmlMap.readValue(xmlString, College.class);  System.out.println(colg.getCollegeName());  System.out.println(colg.getUniversityName());  System.out.println(colg.getAddress());  System.out.println(colg.getRank());  } catch (JsonMappingException e) {  // TODO Auto-generated catch block  e.printStackTrace();  } catch (JsonProcessingException e) {  // TODO Auto-generated catch block  e.printStackTrace();  }  }    }  //create class College  class College {        //Creating properties of College class   @JsonProperty(“name”)  private String name;        @JsonProperty(“university”)  private String university;  private String address;  private String rank;     public String getCollegeName() {    return name;    }  public void setCollegeName(String name) {    this.name = name;    }    public String getUniversityName() {    return university;    }  public void setUniversityName(String university) {    this.university = university;  }  public String getAddress() {    return address;    }  public void setAddress(String address) {    this.address = address;    }  public String getRank() {    return rank;    }  public void setRank(String rank) {    this.rank = rank;    }    }  </p>

Output:

XML Serialization and Deserialization with Jackson

De-serialize data from the XML file

In order to deserialize the data of the XML file into POJO, we use the following steps:

1. Create an instance of the XmlMapper class in the following way:

2. Read data from xml file as a string and store it in a String variable.

3. Use the readValue() method of the XmlMapper class and pass the XML string and name of the class in which XML string is to be deserialized.

Let’s take an example to understand how we can use it to deserialize the data of XML file into POJO.

XMLToPojoExample2.java

  //import required classes and package if any    import com.fasterxml.jackson.core.JsonProcessingException;  import com.fasterxml.jackson.databind.JsonMappingException;  import com.fasterxml.jackson.dataformat.xml.XmlMapper;    import java.io.BufferedReader;  import java.io.File;  import java.io.FileInputStream;  import java.io.IOException;  import java.io.InputStream;  import java.io.InputStreamReader;  import com.fasterxml.jackson.annotation.JsonProperty;  //create class XMLToPojoExample2  public class XMLToPojoExample2 {    //main() methods start    public static void main(String args[]) throws IOException {    // create an instance of XmlMapper class    XmlMapper xmlMap = new XmlMapper();    // create instance of File  File file = new File(“C:\Users\rastogi ji\Desktop\College.xml”);  // read data from College.xml and store it into xmlString  String xmlString;  InputStream data = new FileInputStream(file);  StringBuilder builder = new StringBuilder();      String line;      BufferedReader reader = new BufferedReader(new InputStreamReader(data));      while ((line = reader.readLine()) != null) {          builder.append(line);      }      reader.close();      xmlString = builder.toString();      System.out.println(xmlString);  try {  //deserialize xmlString into POJO  College colg = xmlMap.readValue(xmlString, College.class);  System.out.println(colg.getCollegeName());  System.out.println(colg.getUniversityName());  System.out.println(colg.getAddress());  System.out.println(colg.getRank());    } catch (JsonMappingException e) {  // TODO Auto-generated catch block  e.printStackTrace();  } catch (JsonProcessingException e) {  // TODO Auto-generated catch block  e.printStackTrace();  }  }    }  //create class College  class College {        //Creating properties of College class   @JsonProperty(“name”)  private String name;        @JsonProperty(“university”)  private String university;    private String address;    private String rank;       public String getCollegeName() {    return name;    }  public void setCollegeName(String name) {    this.name = name;    }    public String getUniversityName() {    return university;    }  public void setUniversityName(String university) {    this.university = university;  }  public String getAddress() {    return address;    }  public void setAddress(String address) {    this.address = address;    }  public String getRank() {    return rank;    }  public void setRank(String rank) {    this.rank = rank;    }  }  

Output:

XML Serialization and Deserialization with Jackson

Handle Capitalized Elements

In this section, we will understand how we can handle the cases where we have XML with capitalized elements to deserialize, or we need to serialize Java objects to XML with one or more capitalized elements.

Let’s understand both the cases one by one with an example.

De-serialize data from the XML string

We de-serialize the following XML into POJO by using XmlMapper:

  <College>  <NAME>ABES</NAME>  <UNIVERSITY>AKTU</UNIVERSITY>  <address>  NH-24 GZB UP  </address>  <rank>1</rank>  </College>  

HandleCapitalizedElement1.java

  //import required classes and package if any      import com.fasterxml.jackson.core.JsonProcessingException;  import com.fasterxml.jackson.databind.JsonMappingException;  import com.fasterxml.jackson.dataformat.xml.XmlMapper;  import com.fasterxml.jackson.annotation.JsonProperty;    //create class HandleCapitalizedElement1  public class HandleCapitalizedElement1 {      //main() methods start    public static void main(String args[]) {      // create an instance of XmlMapper class    XmlMapper xmlMap = new XmlMapper();      // xmlString  String xmlString = “ABESAKTU”  + “
<address>NH-24 Highway GZB UP</address>
<p>1″;    try {    College colg = xmlMap.readValue(xmlString, College.class);    System.out.println(colg.getCollegeName());  System.out.println(colg.getUniversityName());  System.out.println(colg.getAddress());  System.out.println(colg.getRank());    } catch (JsonMappingException e) {  // TODO Auto-generated catch block  e.printStackTrace();  } catch (JsonProcessingException e) {  // TODO Auto-generated catch block  e.printStackTrace();  }  }    }  //create class College  class College {        //Creating properties of College class   @JsonProperty(“NAME”)  private String name;        @JsonProperty(“UNIVERSITY”)  private String university;    private String address;    private String rank;       public String getCollegeName() {    return name;    }  public void setCollegeName(String name) {    this.name = name;    }    public String getUniversityName() {    return university;    }  public void setUniversityName(String university) {    this.university = university;  }  public String getAddress() {    return address;    }  public void setAddress(String address) {    this.address = address;    }  public String getRank() {    return rank;    }  public void setRank(String rank) {    this.rank = rank;    }  }  </p>

Output:

XML Serialization and Deserialization with Jackson

Serialize POJO to the XML string

We serialize the POJO into the XML string or XML file with one or more capitalized elements in the following way:

HandleCapitalizedElement2.java

  //import required classes and package if any    import java.io.IOException;    import java.util.Scanner;    import com.fasterxml.jackson.annotation.JsonProperty;  import com.fasterxml.jackson.dataformat.xml.XmlMapper;    //create class HandleCapitalizedElement2  public class HandleCapitalizedElement2 {      //main() methods start    public static void main(String args[]) {      // create an instance of XmlMapper class    XmlMapper xmlMap = new XmlMapper();      // create Scanner class object    Scanner sc= new Scanner(System.in);           // using try-catch  try {      College colg;      String name, university, street, state, city, rank;      System.out.println(“Enter College Name:”);    name = sc.nextLine();      System.out.println(“Enter University Name:”);    university = sc.nextLine();      System.out.println(“Enter Street:”);    street = sc.nextLine();      System.out.println(“Enter City:”);    city = sc.nextLine();    System.out.println(“Enter State:”);    state = sc.nextLine();    System.out.println(“Enter College Rank:”);    rank = sc.nextLine();      // set values to College  object by using constructor    colg = new College(name, university, new Address(street, state, city), rank);    // serialize College using xmlMap    String xmlString = xmlMap  .writeValueAsString(colg);    System.out.println(xmlString);                  } catch (IOException e) {     e.printStackTrace();    }      //close Scanner class object    sc.close();      }    }  //create class College  class College {        //Creating properties of College class    @JsonProperty(“NAME”)  public String name;    @JsonProperty(“UNIVERSITY”)  public String university;     public Address address;   public String rank;       // constructor    College(String name, String university, Address address, String rank){    this.name = name;    this.university = university;    this.address = address;    this.rank = rank;    }      }  //create class Address   class Address {    public String street;  public String state;  public String city;    Address(String street, String state, String city){      this.street = street;    this.state = state;    this.city = city;  }           }  

Output:

XML Serialization and Deserialization with Jackson

Serialize/de-serialize List to/from XML

We can easily serialize an entire Java bean into a document by using XmlMapper class. We will create a Company.java class having fields such as comName, comEmail, address and contacts and serialize it into XML. We use the @JacksonXmlElementWrapper annotation for serializing the list.

SerializeListToXML.java

  //import required classes and package if any    import java.io.IOException;  import java.util.ArrayList;  import java.util.List;  import java.util.Scanner;    import com.fasterxml.jackson.dataformat.xml.XmlMapper;  import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlElementWrapper;    //create class SerializeListToXML  public class SerializeListToXML {      //main() methods start    public static void main(String args[]) {      // create an instance of XmlMapper class    XmlMapper xmlMap = new XmlMapper();      // create Scanner class object    Scanner sc= new Scanner(System.in);           // using try-catch  try {      Company company;      String name, email, mailingCity, mailingState, mailingStreet, shippingCity, shippingState, shippingStreet, con1, con2;    List<String> contacts = new ArrayList<String>();  List<Address> address = new ArrayList<Address>();    System.out.println(“Enter Company Name:”);    name = sc.nextLine();      System.out.println(“Enter Company Email:”);    email = sc.nextLine();      System.out.println(“Enter Mailing Street:”);    mailingStreet = sc.nextLine();      System.out.println(“Enter Mailing City:”);    mailingCity = sc.nextLine();    System.out.println(“Enter Mailing State:”);    mailingState = sc.nextLine();    System.out.println(“Enter Shipping Street:”);    shippingStreet = sc.nextLine();      System.out.println(“Enter Shipping City:”);    shippingCity = sc.nextLine();    System.out.println(“Enter Shipping State:”);    shippingState = sc.nextLine();    System.out.println(“Enter Contact 1:”);    con1 = sc.nextLine();      System.out.println(“Enter Contact 2:”);    con2 = sc.nextLine();      contacts.add(con1);  contacts.add(con2);  address.add(new Address(mailingStreet, mailingCity, mailingState));  address.add(new Address(shippingStreet, shippingCity, shippingState));    // set values to company  object by using constructor    company = new Company(name, email, address, contacts);    // serialize College using xmlMap    String xmlString = xmlMap  .writeValueAsString(company);    System.out.println(xmlString);                  } catch (IOException e) {     e.printStackTrace();    }      //close Scanner class object    sc.close();      }    }  //create class Company  class Company {        //Creating properties of Company class    public String comName;  public String comEmail;       @JacksonXmlElementWrapper(useWrapping = false)  public List<Address> address;   public List<String> contacts;       // constructor    Company(String comName, String comEmail, List<Address> address, List<String> contacts){    this.comName = comName;    this.comEmail = comEmail;    this.address = address;    this.contacts = contacts;    }    }  //create class Address   class Address {    public String street;  public String state;  public String city;    Address(String street, String state, String city){      this.street = street;    this.state = state;    this.city = city;  }           }  

Output:

XML Serialization and Deserialization with Jackson

XMLMapper class automatically deserialize the list xml element without using any additional annotation. Let’s take an example to understand how we use XMLMapper to deserialize XML string having list elements.

DeserializeListFromXML.java

  //import required classes and package if any    import com.fasterxml.jackson.core.JsonProcessingException;  import com.fasterxml.jackson.databind.JsonMappingException;  import com.fasterxml.jackson.dataformat.xml.XmlMapper;  import java.util.List;    //create class DeserializeListFromXML  public class DeserializeListFromXML {    //main() methods start    public static void main(String args[]) {      // create an instance of XmlMapper class    XmlMapper xmlMap = new XmlMapper();      // xmlString  String xmlString = “Tutor Aspirehelp@tutoraspire.com”  + “
<address>
<address>New York USA</address>
<address>New York USA</address>
</address>
<p>”  + “+1-xxx-xxx-xx+1-xxx-xxx-xx”;    try {    Company cmp = xmlMap.readValue(xmlString, Company.class);    System.out.println(cmp.getCompanyName());  System.out.println(cmp.getCompanyEmail());  System.out.println(cmp.getContacts());  System.out.println(cmp.getAddress());    } catch (JsonMappingException e) {  // TODO Auto-generated catch block  e.printStackTrace();  } catch (JsonProcessingException e) {  // TODO Auto-generated catch block  e.printStackTrace();  }  }    }  //create class Company  class Company {        //Creating properties of Company class    public String comName;    public String comEmail;       public List address;    public List contacts;       public String getCompanyName() {    return comName;    }  public void setCompanyName(String comName) {    this.comName = comName;    }  public String getCompanyEmail() {    return comEmail;    }  public void setCompanyEmail(String comEmail) {    this.comEmail = comEmail;    }    public List getContacts() {    return contacts;    }  public void setContacts(List contacts) {    this.contacts = contacts;  }  public List getAddress() {    return address;    }  public void setAddress(List address) {    this.address = address;    }  @Override      public String toString() {          return “Dataset{” +                  “Name=” + comName +                  “, Email=” + comEmail +                  “, Address=” + address +                  “, Contact=” + contacts +                  ‘}’;      }  }  </p>

Output:

XML Serialization and Deserialization with Jackson

Next TopicParsing String to JsonNode Jackson

XML Serialization and Deserialization with Jackson

XML Serialization and Deserialization with Jackson

Note: Please add the latest version of Jackson-dataformat-xml dependency.

XmlMapper Object

Serializing Java Object into XML

Serialize POJO to XML String

Serialize POJO to XML File

Deserializing XML into POJO

De-serialize data from the XML String

De-serialize data from the XML file

Handle Capitalized Elements

Serialize POJO to the XML string

Serialize/de-serialize List to/from XML

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