Using Gson fromJson() to Create Instances of Java Classes from JSON With Dynnamic @SerializedName Annotation Value

Question

I have this JSON snippet. My problem is the key under transactions{} in this example it is set to "Request ID 000002" However this is part of a response to an API request and that value will change. It will always be what is between the [] in the "found detail" property, but I won't know what it is until I POST the request and receive the response.

 "response_state" : {
      "filter_records_removed" : 0,
      "filter_records_reviewed" : 1,
      "filter_redaction" : false,
      "found" : 1,
      "found_detail" : "Found Records [Request ID 000002] available the time of query",
      "missing" : 0,
      "results" : true,
            "transactions" : {
                "Request ID 000002" : {
            "complete" : false,
            "confirmed" : false,
            "event_transaction_id" : "Request ID 000002",
            "event_type" : "software_update",
            "expiration_mark" : false,
            "expiry" : 1727559823240 
}
}

This is the Java Class. I can't really define the value of the @SerializedName ahead of time like it is here in the example.

public class EFDTransactions {
 
    @SerializedName("Request ID 000002")
    @Expose private EFDTransaction transaction; 
    

    public EFDTransactions() {
        // TODO Auto-generated constructor stub
    }

    public EFDTransaction getTransaction() {
        return transaction;
    }

    public void setTransaction(EFDTransaction transaction) {
        this.transaction = transaction;
    }

I am trying to create the class structure so that I can do something like this, where I have already created a JsonObject from the JSON string that was returned from the API request:

Gson rspgson = new GsonBuilder().excludeFieldsWithoutExposeAnnotation() 
                .create();//new Gson();
//responsejobj is the JsonObject created from the JSON string that is the response
        EFDTransactions trans = rspgson.fromJson(responsejobj,EFDTransactions.class);

Do I need to write a custom deserializer? I found this thread on using Reflection to modify the @SerializedName annotation value. I have not tried it yet. Is there another approach?

Modify a class definition's annotation string parameter at runtime

I found this thread, but this isn't Java: Set Dynamic SerializedName annotation for Gson data class

I found this thread and tried creating a Map, that did not work. The map was null after the fromJson(). It works using the above class with the test known value for @SerializedName: Set Dynamic SerializedName annotation in android java

Here is the same class I created with a Map

public class EFDTransactions {

@Expose public Map<String, EFDTransaction> transaction;


public EFDTransactions() {
    // TODO Auto-generated constructor stub
}

public Map<String, EFDTransaction> getTransaction() {
    return transaction;
}

It is transactions, with an s. It should work with the map. — Peter Adrian
– Peter Adrian, Commented Jun 20 at 8:31
to be clear the Map variable name should be "transactions" and not "transaction"? I just tried that, and it did not work. The Map now declaration looks like this: @Expose public Map<String, EFDTransaction> transactions; — crokett
– crokett, Commented Jun 20 at 12:45

crokett · Accepted Answer · 2025-06-21 01:05:17Z

0

I figured out the problem. I had this where the RootObject class has an EFDTransaction class defined that then has the Map<> defined in it:



public class RootObject {
    
    
    @SerializedName("transactions") 
    @Expose private EFDTransactions transaction; 
    
}

public class EFDTransactions {

    @Expose public Map<String, EFDTransaction> transactions = new HashMap<String, EFDTransaction>();
}

public class EFDEventTransaction {
    
    @SerializedName("complete") 
    @Expose private boolean complete; 
}

What I should have done is this where the Map<> is defined directly in the RootObject class



public class RootObject {
    
    @SerializedName("transactions") 
    @Expose public Map<String, EFDTransaction> transactions = new HashMap<String, EFDTransaction>();
    
}

answered Jun 21 at 1:05

crokett

1,2341 gold badge22 silver badges39 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Using Gson fromJson() to Create Instances of Java Classes from JSON With Dynnamic @SerializedName Annotation Value

1 Answer 1

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related