Firebase serialization names

Question

I created an object to send some data to firebase. As an example, I use firebase user example:

public class User {
    public String username;
    public String email;

    public User() {
        // Default constructor required for calls to DataSnapshot.getValue(User.class)
    }

    public User(String username, String email) {
        this.username = username;
        this.email = email;
    }
}

I want to encode property names that are sent to firebase. Currently keys are sent using variable names. I want to encode keys something like Useraname and Email, like Gson is doing. I don't want to change variable names.

@SerializateName("Username")
public String username;
@SerializateName("Username")
public String email;

I used @SerializateName(), but is not working. Same with @PropertyName that is used by Firebse, is not working. What I can use in order to serializare custom keys?

Update 1

public class Pojo {
    @PropertyName("Guid")
    public String guid;

   @PropertyName("Name")
   public String name;

   public String getPojoGuid() {
       return guid;
   }

   public void setPojoGuid(String guid) {
       this.guid = guid;
   }
}

As you can see in the image, it saves keys based on variable names. I changed property name from annotation for one field and when i save it, it ignores it, but when i change variable name, it save as new entry with key for that new varialbe name.

In this documentation is a method toMap(). If i do like that, is working (is not convenient for me), but is not working with @PropertyName.

Update 2

If i mark getters and setters with @Exclude and class with @IgnoreExtraProperties is working. I don't have to use toMap() method example from documetation. Is using specified name from @PropertyName. Not a good thing in my opinion, create confuses.

@PropertyName works for me with version 11.0.2 of the SDK. What version are you using? — Bob Snyder, Jul 25 '17 at 17:48
Please share the minimum code that reproduces the problem when you serialize/deserializing a POJO with `PropertyName` annotations. — Frank van Puffelen, Jul 26 '17 at 04:23
Can you help me with this [question](https://stackoverflow.com/questions/47438092/in-app-billing-connect-to-firebase-and-get-products) please? — StuartDTO, Nov 27 '17 at 09:33

score 20 · Accepted Answer · edited Jul 26 '17 at 15:19

The Firebase SDK uses the annotation it finds for the property whenever it gets or sets its value. That means you need to consider how Firebase gets/sets the value, and annotate each place it looks.

Since you're declaring a getter method, Firebase will use that to get the value of the property. It will use the field for setting the value. So the annotation needs to be on both:

public class Pojo {
   @PropertyName("Guid")
   public String guid;

   @PropertyName("Name")
   public String name;

   @PropertyName("Guid")
   public String getPojoGuid() {
       return guid;
   }

   @PropertyName("Guid")
   public void setPojoGuid(String guid) {
       this.guid = guid;
   }
}

If you'd have getters and setters, the annotation would need to be on those, but not on the fields anymore:

public class Pojo {
   private String guid;
   private String name;

   @PropertyName("Guid")
   public String getPojoGuid() {
       return guid;
   }

   @PropertyName("Guid")
   public void setPojoGuid(String value) {
       guid = value;
   }

   @PropertyName("Name")
   public void setPojoGuid(String guid) {
       this.guid = guid;
   }

   @PropertyName("Name")
   public void setPojoGuid(String value) {
       name = value;
   }
}

Yup. Good point. I updated the code fragment in my answer. Note that you can also just use public fields without getters. I now frequently do this in answer, simply because it's less code to share. — Frank van Puffelen, Jul 26 '17 at 14:56

Alex Mamo · Answer 2 · 2019-09-10T08:09:52.293

3

What you are looking for is the feature of SDK Version 9.2 in which you can now use a new @PropertyName attribute to specify the name to use when serializing a field from a Java model class to the database. This replaces the @JsonProperty attribute.

@PropertyName("Username")
public String username;
@PropertyName("Email")
public String email;

See also this post in which Frank van Puffelen explains very clearly this concept.

edited Sep 10 '19 at 08:09

answered Jul 25 '17 at 15:28

Alex Mamo

130,605
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I use the latest version. I specified in my question that I tried using `@PropertyName`. – Cătălin Florescu Jul 26 '17 at 12:34

score 2 · Answer 3 · answered Jul 25 '17 at 14:52

2

@PropertyName :

Marks a field to be renamed when serialized. link

you have to use @PropertyName with public fields and no need for getters/setters

answered Jul 25 '17 at 14:52

Oussema Aroua

5,225
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1

Is not working. It update keys with same variable name, like `username`, not `@PropertyName("Username")` – Cătălin Florescu Jul 25 '17 at 15:07
Can you help me with this [question](https://stackoverflow.com/questions/47438092/in-app-billing-connect-to-firebase-and-get-products) please? – StuartDTO Nov 27 '17 at 09:33

Firebase serialization names

3 Answers3

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