Gunakan EnhancedDocument tanpa DynamoDB

Meskipun Anda biasanya menggunakan instance EnhancedDocument untuk membaca dan menulis item DynamoDB tipe dokumen, itu juga dapat digunakan secara independen dari DynamoDB.

Anda dapat menggunakan kemampuan mereka EnhancedDocuments untuk mengkonversi antara string JSON atau objek kustom ke peta tingkat rendah AttributeValues seperti yang ditunjukkan dalam contoh berikut.

    public static void conversionWithoutDynamoDbExample() {
        Address address = new Address();
        address.setCity("my city");
        address.setState("my state");
        address.setStreet("my street");
        address.setZipCode("00000");

        // Build an EnhancedDocument instance for its conversion functionality alone.
        EnhancedDocument addressEnhancedDoc = EnhancedDocument.builder()
                // Important: You must specify attribute converter providers when you build an EnhancedDocument instance not used with a DynamoDB table.
                .attributeConverterProviders(new CustomAttributeConverterProvider(), DefaultAttributeConverterProvider.create())
                .put("addressDoc", address, Address.class)
                .build();

        // Convert address to a low-level item representation.
        final Map<String, AttributeValue> addressAsAttributeMap = addressEnhancedDoc.getMapOfUnknownType("addressDoc");
        logger.info("addressAsAttributeMap: {}", addressAsAttributeMap.toString());

        // Convert address to a JSON string.
        String addressAsJsonString = addressEnhancedDoc.getJson("addressDoc");
        logger.info("addressAsJsonString: {}", addressAsJsonString);
        // Convert addressEnhancedDoc back to an Address instance.
        Address addressConverted =  addressEnhancedDoc.get("addressDoc", Address.class);
        logger.info("addressConverted: {}", addressConverted.toString());
    }

   /* Console output:
          addressAsAttributeMap: {zipCode=AttributeValue(S=00000), state=AttributeValue(S=my state), street=AttributeValue(S=my street), city=AttributeValue(S=my city)}
          addressAsJsonString: {"zipCode":"00000","state":"my state","street":"my street","city":"my city"}
          addressConverted: Address{street='my street', city='my city', state='my state', zipCode='00000'}
   */ 

catatan

Bila Anda menggunakan dokumen yang disempurnakan independen dari tabel DynamoDB, pastikan Anda secara eksplisit menetapkan penyedia konverter atribut pada pembangun.

Sebaliknya, skema tabel dokumen memasok penyedia konverter ketika dokumen yang disempurnakan digunakan dengan tabel DynamoDB.