執行 CRUD 作業

定義EnhancedDocument執行個體之後，您可以將其儲存至 DynamoDB 表格。下列程式碼片段會使用從個別元素建立的 PersDocument。

documentDynamoDbTable.putItem(personDocument);

從 DynamoDB 讀取增強的文件執行個體之後，您可以使用 getter 擷取個別屬性值，如下列程式碼片段所示，這些程式碼片段可存取從中儲存的資料。personDocument或者，您也可以將完整內容擷取至 JSON 字串，如範例程式碼的最後一部分所示。

        // Read the item.
        EnhancedDocument personDocFromDb = documentDynamoDbTable.getItem(Key.builder().partitionValue(50).build());

        // Access top-level attributes.
        logger.info("Name: {} {}", personDocFromDb.getString("firstName"), personDocFromDb.getString("lastName"));
        // Name: Shirley Rodriguez

        // Typesafe access of a deeply nested attribute. The addressMapEnhancedType shown previously defines the shape of an addresses map.
        Map<String, Map<String, String>> addresses = personDocFromDb.getMap("addresses", EnhancedType.of(String.class), addressMapEnhancedType);
        addresses.keySet().forEach(k -> logger.info(addresses.get(k).toString()));
        // {zipCode=00002, city=Any Town, street=123 Any Street, state=ME}

        // Alternatively, work with AttributeValue types checking along the way for deeply nested attributes.
        Map<String, AttributeValue> addressesMap = personDocFromDb.getMapOfUnknownType("addresses");
        addressesMap.keySet().forEach((String k) -> {
            logger.info("Looking at data for [{}] address", k);
            // Looking at data for [home] address
            AttributeValue value = addressesMap.get(k);
            AttributeValue cityValue = value.m().get("city");
            if (cityValue != null) {
                logger.info(cityValue.s());
                // Any Town
            }
        });

        List<AttributeValue> phoneNumbers = personDocFromDb.getListOfUnknownType("phoneNumbers");
        phoneNumbers.forEach((AttributeValue av) -> {
            if (av.hasM()) {
                AttributeValue type = av.m().get("type");
                if (type.s() != null) {
                    logger.info("Type of phone: {}", type.s());
                    // Type of phone: Home
                    // Type of phone: Work
                }
            }
        });

        String jsonPerson = personDocFromDb.toJson();
        logger.info(jsonPerson);
        // {"firstName":"Shirley","lastName":"Rodriguez","addresses":{"home":{"zipCode":"00002","city":"Any Town","street":"123 Any Street","state":"ME"}},"hobbies":["Theater","Golf"],
        //     "id":50,"nullAttribute":null,"age":53,"phoneNumbers":[{"number":"555-0140","type":"Home"},{"number":"555-0155","type":"Work"}]}

EnhancedDocument實例可以與任何方法一起使用，DynamoDbTable也DynamoDbEnhancedClient可以代替映射的數據類。