Custom Json serialization format for MonetaryAmount JSR354 / moneta, How to register the Serializer properly

Question

Hello stackoverflow experts

I have the following InvoiceItem Class which has monetary Amounts

import jakarta.json.bind.annotation.JsonbProperty;
import jakarta.json.bind.annotation.JsonbTypeSerializer;
import jakarta.json.bind.serializer.JsonbSerializer;
import jakarta.json.bind.serializer.SerializationContext;
import jakarta.json.stream.JsonGenerator;
import jakarta.persistence.*;
import lombok.Getter;
import lombok.Setter;
import org.eclipse.persistence.annotations.UuidGenerator;
import org.javamoney.moneta.FastMoney;

@Entity
@UuidGenerator(name = "INVOICE_ITEM_GEN")
@Table(name = "invoice_items")
public class InvoiceItem {
    @Getter
    @Setter
    @jakarta.persistence.Id
    @JsonbProperty("id")
    @GeneratedValue(generator = "INVOICE_ITEM_GEN")
    private String Id;

    @Getter
    @Setter
    @Column(name = "name")
    @JsonbProperty("name")
    private String Name;

    @Getter
    @Setter
    @Convert(converter = PersistentFastMoney.class)
    @Column(name = "price")
    @JsonbProperty("price")
    private FastMoney Price;

    public InvoiceItem() {
    }

    public InvoiceItem(String name, String price) {
        this.setName(name);
        this.setPrice(FastMoney.parse(price));
    }
}

I generate this sucessfully in my function from a different input.

import jakarta.ws.rs.Consumes;
import jakarta.ws.rs.POST;
import jakarta.ws.rs.Path;
import jakarta.ws.rs.Produces;
import jakarta.ws.rs.core.MediaType;

@Path("/invoices")
public class InvoiceSystem {

    @POST
    @Produces(MediaType.APPLICATION_JSON)
    @Consumes(MediaType.APPLICATION_JSON)
    public Invoice CreateNewInvoice(InvoiceInput input) {
        var invoice = new Invoice();
        invoice.setCreditor(new InvoiceParty());
        for (var item: input.getItems()) {
            invoice.Items.add(item.toInvoiceItem());
        }

        return invoice;
    }
}

the toInvoiceItem uses the Contructor of InvoiceItem with two string parameters. Now I want to print the Class as JSON back to the Consumer after it has been created.

But this fails with

<body><h1>HTTP Status 500 - Internal Server Error</h1>
<hr/>
<p><b>type</b> Exception report</p>
<p><b>message</b>Internal Server Error</p>
<p><b>description</b>The server encountered an internal error that prevented it from fulfilling this request.</p>
<p><b>exception</b>
<pre>javax.servlet.ServletException: javax.json.bind.JsonbException: Unable to serialize property &#39;Items&#39; from com.openflowlabs.faktura.Invoice</pre>
</p><p><b>root cause</b>
<pre>javax.json.bind.JsonbException: Unable to serialize property &#39;Items&#39; from com.openflowlabs.faktura.Invoice</pre>
</p><p><b>root cause</b>
<pre>javax.json.bind.JsonbException: Unable to serialize property &#39;price&#39; from com.openflowlabs.faktura.InvoiceItem</pre>
</p><p><b>root cause</b>
<pre>javax.json.bind.JsonbException: Unable to serialize property &#39;context&#39; from org.javamoney.moneta.FastMoney</pre>
</p><p><b>root cause</b>
<pre>javax.json.bind.JsonbException: Unable to serialize property &#39;amountType&#39; from javax.money.MonetaryContext</pre>
</p><p><b>root cause</b>
<pre>javax.json.bind.JsonbException: Unable to serialize property &#39;annotatedInterfaces&#39; from java.lang.Class</pre>
</p><p><b>root cause</b>
<pre>javax.json.bind.JsonbException: Unable to serialize property &#39;annotatedOwnerType&#39; from sun.reflect.annotation.AnnotatedTypeFactory.AnnotatedTypeBaseImpl</pre>
</p><p><b>root cause</b>
<pre>javax.json.bind.JsonbException: Error getting value on: javax.money.MonetaryAmount</pre>
</p><p><b>root cause</b>
<pre>java.lang.IllegalAccessException: class org.eclipse.yasson.internal.model.ReflectionPropagation cannot access class sun.reflect.annotation.AnnotatedTypeFactory$AnnotatedTypeBaseImpl &#40;in module java.base&#41; because module java.base does not export sun.reflect.annotation to unnamed module @50c1e8e3</pre>
</p><p><b>note</b> <u>The full stack traces of the exception and its root causes are available in the Payara Server
    5.2022.1 #badassfish logs.</u></p>
<hr/>
<h3>Payara Server 5.2022.1 #badassfish</h3></body>

I know I need a Custom Serializer, but I tried for a day every possible way to make one but my App simply wont eat the Annotation

How do I make a Custom serializer for the org.javamoney.moneta.FastMoney Class so that I can simply annotate all fields that have this class with @JsonbTypeSerializer(FastMoneySerializer.class) like for example Invoice Item

@Getter
@Setter
@Convert(converter = PersistentFastMoney.class)
@Column(name = "price")
@JsonbProperty("price")
@JsonbTypeSerializer(FastMoneySerializer.class)
private FastMoney Price;

Is this possible somehow? Is there some documentation on how I would need to make the Serializer so it returns the JSON like this?

{
  "name": "Testing",
  "price": "CHF 20"
}

Thanks for any pointers and or Solutions I am really stuck and can't find a tutorial on how to make these Serializers work. If you have a Libarary with good documentation that would also help.

Trying Jackson based on https://stackoverflow.com/questions/11230954/jax-rs-jackson-json-provider-date-format-issue/11233594#11233594 did also not work.... — Toasterson, Feb 27 '22 at 19:21
The stacktrace shows you are using `javax.json` for the runtime, but your code uses `jakarta.json`. — Paul Samsotha, Feb 28 '22 at 03:01
Ah, I am using jakarta in my own code but the moneta library is using javax... Whats the best way to intercept the transformation before it hits moneta so I can do the transformation to JSON — Toasterson, Mar 01 '22 at 18:43

score 0 · Accepted Answer · answered Mar 01 '22 at 20:39

OK, I found a solution.

If you want to use jakarta.json your runtime needs to support it. I was using Pyara which says it supports Jakarta EE9 but somehow it does not. Switching to GlassFish solved that problem. The Correct Serializer was then done like this

package org.mypackage;

import jakarta.json.bind.serializer.JsonbSerializer;
import jakarta.json.bind.serializer.SerializationContext;
import jakarta.json.stream.JsonGenerator;
import org.javamoney.moneta.FastMoney;

public class FastMoneySerializer implements JsonbSerializer<FastMoney> {

    @Override
    public void serialize(FastMoney obj, JsonGenerator generator, SerializationContext ctx) {
        var str = obj.toString();
        generator.write(str);
    }
}

You can then add it to a property that has the FastMoney type like so:

package com.openflowlabs.faktura;

import jakarta.json.bind.annotation.JsonbAnnotation;
import jakarta.json.bind.annotation.JsonbProperty;
import jakarta.json.bind.annotation.JsonbTypeSerializer;
import jakarta.json.bind.serializer.JsonbSerializer;
import jakarta.json.bind.serializer.SerializationContext;
import jakarta.json.stream.JsonGenerator;
import jakarta.persistence.*;
import lombok.Getter;
import lombok.Setter;
import org.eclipse.persistence.annotations.UuidGenerator;
import org.javamoney.moneta.FastMoney;

@Entity
@UuidGenerator(name = "INVOICE_ITEM_GEN")
@Table(name = "invoice_items")
public class InvoiceItem {
    @Getter
    @Setter
    @jakarta.persistence.Id
    @JsonbProperty("id")
    @GeneratedValue(generator = "INVOICE_ITEM_GEN")
    private String Id;

    @Getter
    @Setter
    @Column(name = "name")
    @JsonbProperty("name")
    private String Name;

    @Getter
    @Setter
    @Convert(converter = PersistentFastMoney.class)
    @Column(name = "price")
    @JsonbProperty("price")
    @JsonbTypeSerializer(FastMoneySerializer.class)
    private FastMoney Price;

    public InvoiceItem() {
    }

    public InvoiceItem(String name, String price) {
        this.setName(name);
        this.setPrice(FastMoney.parse(price));
    }
}

can you explain why this works or the concept behind this solution please — kinsley kajiva, Feb 15 '23 at 21:53
Well, payara was not supporting Jakarta EE9 properly at the time of writing. The code in the solution works in Glassfish. — Toasterson, Feb 15 '23 at 22:27

Custom Json serialization format for MonetaryAmount JSR354 / moneta, How to register the Serializer properly

1 Answers1