Question

I’m facing a problem to deserialize an XML file which have successfully been serialized with the Simple XML Serialization framework (simpleframework.org).

There is an exception thrown:

org.simpleframework.xml.core.PersistenceException: Constructor not matched for class projet.sarelo.Note

This is the call:

Serializer serializer = new Persister();
File xmlFile = new File(path);
ContactList contactList = serializer.read(ContactList.class, xmlFile); <== Error

My ContactList.java

@Root(strict=false, name="ContacList")
public class ContactList {      
    @ElementArray (name = "Contacts")
    Contact [] contact;     
}   

My Note.java

public class Note {
    @Element(required=false)
    private String note;

    public Note(String note) {
        super();
        this.note = note;
    }

    public String getNote() {
        return note;
    }
}

My Contact.java

@Root
public class Contact {
@Attribute(name = "id") 
public String id;       

@Element(name="Nom", required=false)                
String name; 

@ElementArray(name="Phones", required=false)
Phone [] phone; 

@ElementArray(name = "Emails", required=false)
Email [] email; 

@ElementArray(name = "Adresses", required=false)
Adresses [] adresses;

@ElementArray(name = "Notes", required=false)
Note [] note;

public Contact(String id, String name) {
    super();
    this.id = id;
    this.name = name;
}

public String getName() {
    return name;
}   

public String getId(){
    return id;
}
}

And this is the XML file I’m trying to deserialize.

<ContactList>
<Contacts length="5">
  <contact id="1">
     <Adresses length="0"/>
     <Emails length="0"/>
     <Notes length="1">
        <note>
           <note>dgfdg</note>
        </note>
     </Notes>
  </contact>
  <contact id="2">
     <Adresses length="1">
        <adresses>
           <city>Paris </city>
           <postcode>751234 </postcode>
           <state>France</state>
           <street>Pignon</street>
        </adresses>
     </Adresses>
     <Emails length="1">
        <email type="home">
           <home>[e-mail]</home>
        </email>
     </Emails>
     <Nom>Nicolas  Sarkozy </Nom>
     <Notes length="1">
        <note>
           <note>Je suis le president de toute la france. Le grand president</note>
        </note>
     </Notes>
     <Phones length="2">
        <phone>
           <home>+33 1234</home>
        </phone>
        <phone>
           <mobile>+33 0612</mobile>
        </phone>
     </Phones>
  </contact>
    ...
</Contacts>
</ContactList>

Answer 1

No-Arg Constructor

I don’t know this particular XML framework, but, usually you need a constructor that takes no parameters/arguments for each class that you wish to be deserialized. Such constructors are known as a “no-arg”, “0-argument”, or (formally) nullary constructor.

Otherwise, the framework cannot instantiate the class.