Tuesday, September 16, 2014

Boon JSON: Custom object serializer now works with super classes, and interfaces. (Example of using Guava HashCode)

related to

Boon JSON: Custom object serializer works with super classes, and interfaces (and example of using HashCodeGuava). 

Let's say you want to write a custom object serializer to work with Guava HashCode thingy or whatever else you need.
    public static String toJson(Object obj) {

        return createSerializer().serialize(obj).toString();

    private static JsonSerializer createSerializer() {
        JsonSerializerFactory factory = new JsonSerializerFactory()
                .addTypeSerializer(HashCode.class, new HashCodeSerializer()
        return factory.create();

    private static class HashCodeSerializer implements CustomObjectSerializer<HashCode> {
        public Class<HashCode> type() {
            return HashCode.class;

        public void serializeObject(JsonSerializerInternal serializer, HashCode instance, CharBuf builder) {
            serializer.serializeString(instance.toString(), builder);
You can use it as an object like so:
    public void test() {
        Hasher hasher = md5().newHasher();
        hasher.putString("heisann", Charset.defaultCharset());
        HashCode hash = hasher.hash();
        String actualJson = toJson(hash);

        ok = actualJson.equals("\"86c7c929d73e1d91c268c9f18d121212\"") || die(actualJson);

Or you can use it from a field like so:
The above works now.
It also works for fields.
    public static class Employee {
        String firstName = "Rick".intern();
        HashCode password = md5().newHasher().putString("BACON!", Charset.defaultCharset()).hash();


    public void testWithField() {
        Employee rick = new Employee();
        String actualJson = toJson(rick);

        /* Convert it back to an employee. */
        Map<String, Object> fromJson = (Map<String, Object>) fromJson(actualJson);

        /* Grab the password an convert it into a HashCode. */
        String password = idxStr(fromJson, "password");
        fromJson = Maps.copy(fromJson);
        /* Convert and shove it back into the map. */
        idx(fromJson, "password", HashCode.fromString(password));

        /* Now convert the map into an Employee. */
        Employee rick2 = fromMap(fromJson, Employee.class);

        ok = rick.firstName == rick2.firstName.intern() || die();

        ok = rick.password.equals(rick2.password) || die(rick2.password);


Example of Using BOON JSON Java, Example of using Guava HashCode, Example of doing custom field conversion in Boon, Example of being awesome. etc. 
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