Perform CRUD operations - Amazon SDK for Java 2.x
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Perform CRUD operations

After you define an EnhancedDocument instance, you can save it to a DynamoDB table. The following code snippet uses the personDocument that was created from individual elements.


After you read an enhanced document instance from DynamoDB, you can extract the individual attribute values using getters as shown in the following code snippet that access the data saved from the personDocument. Alternatively, you can extract the complete content to a JSON string as shown in the last part of the example code.

// Read the item. EnhancedDocument personDocFromDb = documentDynamoDbTable.getItem(Key.builder().partitionValue(50).build()); // Access top-level attributes."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 ->; // {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) -> {"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) {; // 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) {"Type of phone: {}", type.s()); // Type of phone: Home // Type of phone: Work } } }); String jsonPerson = personDocFromDb.toJson();; // {"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 instances can be used with any method of DynamoDbTable or DynamoDbEnhancedClient in place of mapped data classes.