Jackson JSON processor overwrites properties of object during deserialization - json

Question

I have interesting problem. Jackson overwrites values of properties on the 'parent' object with values of properties of 'child' object that have same name. So, to be more precise, this is Java structure I have
public class Contact {
...
String name;
List<Email> emails;
List<PhoneNumbers> phoneNumbers;
Account account;
...
}
public class Account {
...
String accountName;
List<Email> emails;
List<PhoneNumbers> phoneNumbers;
Account account;
...
}
So, when I form Contact JSON object and send it to server, everything goes fine until BeanDeserializer comes into account property of Contact class. Then, it starts reading proeprties of account part of JSON, which is ok, but does not create Account instance to set it on contact - it writes values of account's properties into properties with same names of Contact instance.
I am confused and not sure where to start looking how to fix this.

Answer 1

I'm not able to reproduce any problem similar to what's described in the original question.
The following example, created based on the descriptions in the original question, works as expected, without errors or improper deserialization.
import java.util.LinkedList;
import java.util.List;
import org.codehaus.jackson.annotate.JsonAutoDetect.Visibility;
import org.codehaus.jackson.annotate.JsonCreator;
import org.codehaus.jackson.annotate.JsonProperty;
import org.codehaus.jackson.map.ObjectMapper;
public class JacksonFoo
{
public static void main(String[] args) throws Exception
{
Account account1 = new Account();
account1.accountName = "account 1";
account1.emails = new LinkedList<Email>();
account1.emails.add(new Email("email_11#google.com"));
account1.emails.add(new Email("email_12#google.com"));
account1.phoneNumbers = new LinkedList<PhoneNumbers>();
account1.phoneNumbers.add(new PhoneNumbers(1111, 1112));
account1.phoneNumbers.add(new PhoneNumbers(1113, 1114));
Account account2 = new Account();
account2.accountName = "account 2";
account2.emails = new LinkedList<Email>();
account2.emails.add(new Email("email_21#google.com"));
account2.emails.add(new Email("email_22#google.com"));
account2.phoneNumbers = new LinkedList<PhoneNumbers>();
account2.phoneNumbers.add(new PhoneNumbers(2221, 2222));
account2.phoneNumbers.add(new PhoneNumbers(2223, 2224));
account2.account = account1;
Contact contact = new Contact();
contact.name = "contact";
contact.emails = new LinkedList<Email>();
contact.emails.add(new Email("email_31#google.com"));
contact.emails.add(new Email("email_32#google.com"));
contact.phoneNumbers = new LinkedList<PhoneNumbers>();
contact.phoneNumbers.add(new PhoneNumbers(3331, 3332));
contact.phoneNumbers.add(new PhoneNumbers(3333, 3334));
contact.account = account2;
ObjectMapper mapper = new ObjectMapper();
mapper.setVisibilityChecker(
mapper.getVisibilityChecker()
.withFieldVisibility(Visibility.ANY));
String account1Json = mapper.writeValueAsString(account1);
String account2Json = mapper.writeValueAsString(account2);
String contactJson = mapper.writeValueAsString(contact);
System.out.println(account1Json); // {"accountName":"account 1","emails":[{"email":"email_11#google.com"},{"email":"email_12#google.com"}],"phoneNumbers":[{"phone1":1111,"phone2":1112},{"phone1":1113,"phone2":1114}],"account":null}
System.out.println(account2Json); // {"accountName":"account 2","emails":[{"email":"email_21#google.com"},{"email":"email_22#google.com"}],"phoneNumbers":[{"phone1":2221,"phone2":2222},{"phone1":2223,"phone2":2224}],"account":{"accountName":"account 1","emails":[{"email":"email_11#google.com"},{"email":"email_12#google.com"}],"phoneNumbers":[{"phone1":1111,"phone2":1112},{"phone1":1113,"phone2":1114}],"account":null}}
System.out.println(contactJson); // {"name":"contact","emails":[{"email":"email_31#google.com"},{"email":"email_32#google.com"}],"phoneNumbers":[{"phone1":3331,"phone2":3332},{"phone1":3333,"phone2":3334}],"account":{"accountName":"account 2","emails":[{"email":"email_21#google.com"},{"email":"email_22#google.com"}],"phoneNumbers":[{"phone1":2221,"phone2":2222},{"phone1":2223,"phone2":2224}],"account":{"accountName":"account 1","emails":[{"email":"email_11#google.com"},{"email":"email_12#google.com"}],"phoneNumbers":[{"phone1":1111,"phone2":1112},{"phone1":1113,"phone2":1114}],"account":null}}}
Account account1Copy = mapper.readValue(account1Json, Account.class);
Account account2Copy = mapper.readValue(account2Json, Account.class);
Contact contactCopy = mapper.readValue(contactJson, Contact.class);
System.out.println(account1.equals(account1Copy)); // true
System.out.println(account2.equals(account2Copy)); // true
System.out.println(contact.equals(contactCopy)); // true
}
}
class Contact
{
String name;
List<Email> emails;
List<PhoneNumbers> phoneNumbers;
Account account;
#Override
public boolean equals(Object o)
{
Contact c = (Contact) o;
if (name.equals(c.name))
if (emails.containsAll(c.emails))
if (c.emails.containsAll(emails))
if (phoneNumbers.containsAll(c.phoneNumbers))
if (c.phoneNumbers.containsAll(phoneNumbers))
return account.equals(c.account);
return false;
}
}
class Account
{
String accountName;
List<Email> emails;
List<PhoneNumbers> phoneNumbers;
Account account;
#Override
public boolean equals(Object o)
{
Account a = (Account) o;
if (accountName.equals(a.accountName))
if (emails.containsAll(a.emails))
if (a.emails.containsAll(emails))
if (phoneNumbers.containsAll(a.phoneNumbers))
if (a.phoneNumbers.containsAll(phoneNumbers))
if (account != null && a.account != null)
return account.equals(a.account);
else if (account == null && a.account == null)
return true;
return false;
}
}
class Email
{
String email;
#JsonCreator
Email(#JsonProperty("email") String e) {email = e;}
#Override
public boolean equals(Object o)
{
Email e = (Email) o;
return email.equals(e.email);
}
}
class PhoneNumbers
{
long phone1;
long phone2;
#JsonCreator
PhoneNumbers(#JsonProperty("phone1") long p1, #JsonProperty("phone2")long p2) {phone1 = p1; phone2 = p2;}
#Override
public boolean equals(Object o)
{
PhoneNumbers p = (PhoneNumbers) o;
return phone1 == p.phone1 && phone2 == p.phone2;
}
}